Package 'MSstatsPTM'

Title: Statistical Characterization of Post-translational Modifications
Description: MSstatsPTM provides general statistical methods for quantitative characterization of post-translational modifications (PTMs). Supports DDA, DIA, SRM, and tandem mass tag (TMT) labeling. Typically, the analysis involves the quantification of PTM sites (i.e., modified residues) and their corresponding proteins, as well as the integration of the quantification results. MSstatsPTM provides functions for summarization, estimation of PTM site abundance, and detection of changes in PTMs across experimental conditions.
Authors: Devon Kohler [aut, cre], Tsung-Heng Tsai [aut], Ting Huang [aut], Mateusz Staniak [aut], Meena Choi [aut], Olga Vitek [aut]
Maintainer: Devon Kohler <[email protected]>
License: Artistic-2.0
Version: 2.7.1
Built: 2024-09-25 03:24:25 UTC
Source: https://github.com/bioc/MSstatsPTM

Help Index


Annotate modification site

Description

annotSite annotates modified sites as their residues and locations.

Usage

annotSite(aaIndex, residue, lenIndex = NULL)

Arguments

aaIndex

An integer vector. Location of the sites.

residue

A string vector. Amino acid residue.

lenIndex

An integer. Default is NULL

Value

A string.

Examples

annotSite(10, "K")
annotSite(10, "K", 3L)

Visualization for explanatory data analysis

Description

To illustrate the quantitative data and quality control of MS runs, dataProcessPlotsPTM takes the quantitative data from dataSummarizationPTM or dataSummarizationPTM_TMT to plot the following : (1) profile plot (specify "ProfilePlot" in option type), to identify the potential sources of variation for each protein; (2) quality control plot (specify "QCPlot" in option type), to evaluate the systematic bias between MS runs.

Usage

dataProcessPlotsPTM(
  data,
  type = "PROFILEPLOT",
  ylimUp = FALSE,
  ylimDown = FALSE,
  x.axis.size = 10,
  y.axis.size = 10,
  text.size = 4,
  text.angle = 90,
  legend.size = 7,
  dot.size.profile = 2,
  ncol.guide = 5,
  width = 10,
  height = 12,
  ptm.title = "All PTMs",
  protein.title = "All Proteins",
  which.PTM = "all",
  which.Protein = NULL,
  originalPlot = TRUE,
  summaryPlot = TRUE,
  address = ""
)

Arguments

data

name of the list with PTM and (optionally) Protein data, which can be the output of the MSstatsPTM dataSummarizationPTM or dataSummarizationPTM_TMT functions.

type

choice of visualization. "ProfilePlot" represents profile plot of log intensities across MS runs. "QCPlot" represents box plots of log intensities across channels and MS runs.

ylimUp

upper limit for y-axis in the log scale. FALSE(Default) for Profile Plot and QC Plot uses the upper limit as rounded off maximum of log2(intensities) after normalization + 3..

ylimDown

lower limit for y-axis in the log scale. FALSE(Default) for Profile Plot and QC Plot uses 0..

x.axis.size

size of x-axis labeling for "Run" and "channel in Profile Plot and QC Plot.

y.axis.size

size of y-axis labels. Default is 10.

text.size

size of labels represented each condition at the top of Profile plot and QC plot. Default is 4.

text.angle

angle of labels represented each condition at the top of Profile plot and QC plot. Default is 0.

legend.size

size of legend above Profile plot. Default is 7.

dot.size.profile

size of dots in Profile plot. Default is 2.

ncol.guide

number of columns for legends at the top of plot. Default is 5.

width

width of the saved pdf file. Default is 10.

height

height of the saved pdf file. Default is 10.

ptm.title

title of overall PTM QC plot

protein.title

title of overall Protein QC plot

which.PTM

PTM list to draw plots. List can be names of PTMs or order numbers of PTMs. Default is "all", which generates all plots for each protein. For QC plot, "allonly" will generate one QC plot with all proteins.

which.Protein

List of proteins to plot. Will plot all PTMs associated with listed Proteins. Default is NULL which will default to which.PTM.

originalPlot

TRUE(default) draws original profile plots, without normalization.

summaryPlot

TRUE(default) draws profile plots with protein summarization for each channel and MS run.

address

the name of folder that will store the results. Default folder is the current working directory. The other assigned folder has to be existed under the current working directory. An output pdf file is automatically created with the default name of "ProfilePlot.pdf" or "QCplot.pdf". The command address can help to specify where to store the file as well as how to modify the beginning of the file name. If address=FALSE, plot will be not saved as pdf file but showed in window.

Value

plot or pdf

Examples

# QCPlot
dataProcessPlotsPTM(summary.data,
                    type = 'QCPLOT',
                    which.PTM = "allonly",
                    address = FALSE)
                    
#ProfilePlot
dataProcessPlotsPTM(summary.data,
                    type = 'PROFILEPLOT',
                    which.PTM = "Q9UQ80_K376",
                    address = FALSE)

Data summarization function for label-free MS experiments targeting PTMs.

Description

Utilizes functionality from MSstats to clean, summarize, and normalize PTM and protein level data. Imputes missing values, performs normalization, and summarizes data. PTM data is summarized up to the modification and protein data is summarized up to the protein level. Takes as input the output of the included converters (see included raw.input data object for required input format).

Usage

dataSummarizationPTM(
  data,
  logTrans = 2,
  normalization = "equalizeMedians",
  normalization.PTM = "equalizeMedians",
  nameStandards = NULL,
  nameStandards.PTM = NULL,
  featureSubset = "all",
  featureSubset.PTM = "all",
  remove_uninformative_feature_outlier = FALSE,
  remove_uninformative_feature_outlier.PTM = FALSE,
  min_feature_count = 2,
  min_feature_count.PTM = 1,
  n_top_feature = 3,
  n_top_feature.PTM = 3,
  summaryMethod = "TMP",
  equalFeatureVar = TRUE,
  censoredInt = "NA",
  MBimpute = TRUE,
  MBimpute.PTM = TRUE,
  remove50missing = FALSE,
  fix_missing = NULL,
  maxQuantileforCensored = 0.999,
  use_log_file = TRUE,
  append = TRUE,
  verbose = TRUE,
  log_file_path = NULL,
  base = "MSstatsPTM_log_"
)

Arguments

data

name of the list with PTM and (optionally) unmodified protein data.tables, which can be the output of the MSstatsPTM converter functions

logTrans

logarithm transformation with base 2(default) or 10

normalization

normalization for the protein level dataset, to remove systematic bias between MS runs. There are three different normalizations supported. 'equalizeMedians'(default) represents constant normalization (equalizing the medians) based on reference signals is performed. 'quantile' represents quantile normalization based on reference signals is performed. 'globalStandards' represents normalization with global standards proteins. FALSE represents no normalization is performed

normalization.PTM

normalization for PTM level dataset. Default is "equalizeMedians" Can be adjusted to any of the options described above.

nameStandards

vector of global standard peptide names for protein dataset. only for normalization with global standard peptides.

nameStandards.PTM

Same as above for PTM dataset.

featureSubset

"all" (default) uses all features that the data set has. "top3" uses top 3 features which have highest average of log-intensity across runs. "topN" uses top N features which has highest average of log-intensity across runs. It needs the input for n_top_feature option. "highQuality" flags uninformative feature and outliers.

featureSubset.PTM

For PTM dataset only. Options same as above.

remove_uninformative_feature_outlier

For protein dataset only. It only works after users used featureSubset="highQuality" in dataProcess. TRUE allows to remove 1) the features are flagged in the column, feature_quality="Uninformative" which are features with bad quality, 2) outliers that are flagged in the column, is_outlier=TRUE, for run-level summarization. FALSE (default) uses all features and intensities for run-level summarization.

remove_uninformative_feature_outlier.PTM

For PTM dataset only. Options same as above.

min_feature_count

optional. Only required if featureSubset = "highQuality". Defines a minimum number of informative features a protein needs to be considered in the feature selection algorithm.

min_feature_count.PTM

For PTM dataset only. Options the same as above. Default is 1 due to low average feature count for PTMs.

n_top_feature

For protein dataset only. The number of top features for featureSubset='topN'. Default is 3, which means to use top 3 features.

n_top_feature.PTM

For PTM dataset only. Options same as above.

summaryMethod

"TMP"(default) means Tukey's median polish, which is robust estimation method. "linear" uses linear mixed model.

equalFeatureVar

only for summaryMethod="linear". default is TRUE. Logical variable for whether the model should account for heterogeneous variation among intensities from different features. Default is TRUE, which assume equal variance among intensities from features. FALSE means that we cannot assume equal variance among intensities from features, then we will account for heterogeneous variation from different features.

censoredInt

Missing values are censored or at random. 'NA' (default) assumes that all 'NA's in 'Intensity' column are censored. '0' uses zero intensities as censored intensity. In this case, NA intensities are missing at random. The output from Skyline should use '0'. Null assumes that all NA intensites are randomly missing.

MBimpute

For protein dataset only. only for summaryMethod="TMP" and censoredInt='NA' or '0'. TRUE (default) imputes 'NA' or '0' (depending on censoredInt option) by Accelated failure model. FALSE uses the values assigned by cutoffCensored.

MBimpute.PTM

For PTM dataset only. Options same as above.

remove50missing

only for summaryMethod="TMP". TRUE removes the runs which have more than 50% missing values. FALSE is default.

fix_missing

Default is Null. Optional, same as the 'fix_missing' parameter in MSstatsConvert::MSstatsBalancedDesign function

maxQuantileforCensored

Maximum quantile for deciding censored missing values. default is 0.999

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing will be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If append = TRUE, has to be a valid path to a file.

base

start of the file name.

Value

list of summarized PTM and Protein results. These results contain the reformatted input to the summarization function, as well as run-level summarization results.

Examples

head(raw.input$PTM)
head(raw.input$PROTEIN)

quant.lf.msstatsptm = dataSummarizationPTM(raw.input, verbose = FALSE)
head(quant.lf.msstatsptm$PTM$ProteinLevelData)

Data summarization function for TMT labelled MS experiments targeting PTMs.

Description

Utilizes functionality from MSstatsTMT to clean, summarize, and normalize PTM and protein level data. Imputes missing values, performs normalization, and summarizes data. PTM data is summarized up to the modification and protein data is summarized up to the protein level. Takes as input the output of the included converters (see included raw.input.tmt data object for required input format).

Usage

dataSummarizationPTM_TMT(
  data,
  method = "msstats",
  global_norm = TRUE,
  global_norm.PTM = TRUE,
  reference_norm = TRUE,
  reference_norm.PTM = TRUE,
  remove_norm_channel = TRUE,
  remove_empty_channel = TRUE,
  MBimpute = TRUE,
  MBimpute.PTM = TRUE,
  maxQuantileforCensored = NULL,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

data

Name of the output of MSstatsPTM converter function or peptide-level quantified data from other tools. It should be a list containing one or two data tables, named PTM and PROTEIN for modified and unmodified datasets. The list must at least contain the PTM dataset. The data should have columns ProteinName, PeptideSequence, Charge, PSM, Mixture, TechRepMixture, Run, Channel, Condition, BioReplicate, Intensity

method

Four different summarization methods to protein-level can be performed : "msstats"(default), "MedianPolish", "Median", "LogSum".

global_norm

Global median normalization on for unmodified peptide level data (equalizing the medians across all the channels and MS runs). Default is TRUE. It will be performed before protein-level summarization.

global_norm.PTM

Same as above for modified peptide level data. Default is TRUE.

reference_norm

Reference channel based normalization between MS runs on unmodified protein level data. TRUE(default) needs at least one reference channel in each MS run, annotated by 'Norm' in Condtion column. It will be performed after protein-level summarization. FALSE will not perform this normalization step. If data only has one run, then reference_norm=FALSE.

reference_norm.PTM

Same as above for modified peptide level data. Default is TRUE.

remove_norm_channel

TRUE(default) removes 'Norm' channels from protein level data.

remove_empty_channel

TRUE(default) removes 'Empty' channels from protein level data.

MBimpute

only for method="msstats". TRUE (default) imputes missing values by Accelated failure model. FALSE uses minimum value to impute the missing value for each peptide precursor ion.

MBimpute.PTM

Same as above for modified peptide level data. Default is TRUE

maxQuantileforCensored

We assume missing values are censored. maxQuantileforCensored is Maximum quantile for deciding censored missing value, for instance, 0.999. Default is Null.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing will be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If append = TRUE, has to be a valid path to a file.

Value

list of two data.tables

Examples

head(raw.input.tmt$PTM)
head(raw.input.tmt$PROTEIN)

quant.tmt.msstatsptm = dataSummarizationPTM_TMT(raw.input.tmt,
                                                 method = "msstats", 
                                                 verbose = FALSE)
head(quant.tmt.msstatsptm$PTM$ProteinLevelData)

Planning future experimental designs of PTM experiments in sample size calculation

Description

Calculate sample size for future experiments of a PTM experiment based on intensity-based linear model. Calculation is only available for group comparison experimental designs (not including time series). Two options of the calculation: (1) number of biological replicates per condition, (2) power.

Usage

designSampleSizePTM(
  data,
  desiredFC,
  FDR = 0.05,
  numSample = TRUE,
  power = 0.8,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL,
  base = "MSstatsPTM_log_"
)

Arguments

data

output of the groupComparisonPTM function.

desiredFC

the range of a desired fold change which includes the lower and upper values of the desired fold change.

FDR

a pre-specified false discovery ratio (FDR) to control the overall false positive rate. Default is 0.05

numSample

minimal number of biological replicates per condition. TRUE represents you require to calculate the sample size for this category, else you should input the exact number of biological replicates.

power

a pre-specified statistical power which defined as the probability of detecting a true fold change. TRUE represent you require to calculate the power for this category, else you should input the average of power you expect. Default is 0.9

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing will be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If append = TRUE, has to be a valid path to a file.

base

start of the file name.

Details

The function fits the model and uses variance components to calculate sample size. The underlying model fitting with intensity-based linear model with technical MS run replication. Estimated sample size is rounded to 0 decimal. The function can only obtain either one of the categories of the sample size calculation (numSample, numPep, numTran, power) at the same time.

Value

data.frame - sample size calculation results including varibles: desiredFC, numSample, FDR, and power.

Examples

model.lf.msstatsptm = groupComparisonPTM(summary.data, 
                                     data.type = "LabelFree",
                                     verbose = FALSE)
                                     
#(1) Minimal number of biological replicates per condition
designSampleSizePTM(data=model.lf.msstatsptm, numSample=TRUE,
                 desiredFC=c(2.0,2.75), FDR=0.05, power=0.8)
#(2) Power calculation
designSampleSizePTM(data=model.lf.msstatsptm, numSample=5,
                 desiredFC=c(2.0,2.75), FDR=0.05, power=TRUE)

Convert the output of DIA-NN PSM file into MSstatsPTM format

Description

Takes as input the report.tsv file from DIA-NN and converts it into MSstatsPTM format. Requires PSM and an annotation file. Optionally an additional report.tsv file for a corresponding global profiling run can be included.

Usage

DIANNtoMSstatsPTMFormat(
  input,
  annotation,
  input_protein = NULL,
  annotation_protein = NULL,
  fasta_path = NULL,
  use_unmod_peptides = FALSE,
  protein_id_col = "Protein.Group",
  fasta_protein_name = "uniprot_ac",
  global_qvalue_cutoff = 0.01,
  qvalue_cutoff = 0.01,
  pg_qvalue_cutoff = 0.01,
  useUniquePeptide = TRUE,
  removeFewMeasurements = TRUE,
  removeOxidationMpeptides = TRUE,
  removeProtein_with1Feature = FALSE,
  MBR = TRUE,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

input

data.frame of report.tsv file produced by Philosopher

annotation

annotation with Run, Fraction, TechRepMixture, Mixture, Channel, BioReplicate, Condition columns or a path to file. Refer to the example 'annotation' for the meaning of each column.

input_protein

same as input for global profiling run. Default is NULL.

annotation_protein

same as annotation for global profiling run. Default is NULL.

fasta_path

A string of path to a FASTA file, used to match PTM peptides.

use_unmod_peptides

Boolean if the unmodified peptides in the input file should be used to construct the unmodified protein output. Only used if input_protein is not provided. Default is FALSE.

protein_id_col

Use 'Protein.Groups'(default) column for protein name.

fasta_protein_name

Name of column that matches with the protein names in protein_id_col. The protein names in these two columns must match in order to join the FASTA file with the DIA-NN output.

global_qvalue_cutoff

The global qvalue cutoff. Default is 0.01.

qvalue_cutoff

local qvalue cutoff for library. Default is 0.01.

pg_qvalue_cutoff

local qvalue cutoff for protein groups Run should be the same as filename. Default is 0.01.

useUniquePeptide

logical, if TRUE (default) removes peptides that are assigned for more than one proteins. We assume to use unique peptide for each protein.

removeFewMeasurements

TRUE (default) will remove the features that have 1 or 2 measurements within each Run.

removeOxidationMpeptides

TRUE (default) will remove the peptides including oxidation (M) sequence.

removeProtein_with1Feature

TRUE will remove the proteins which have only 1 peptide and charge. Defaut is FALSE.

MBR

If analaysis was done with match between runs or not. Default is TRUE.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing wil be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

list of one or two data.frame of class MSstatsTMT, named PTM and PROTEIN

Examples

# ptm = read.csv("Phospho/report.tsv", sep="\t")
# protein = read.csv("Protein/report.tsv", sep="\t")
# annotation = read.csv("Phospho/annotation.csv")
# annotation_protein = read.csv("Protein/annotation.csv")

#DIANNtoMSstatsPTMFormat(ptm, annotation, 
#                        protein, annotation_protein,
#                        fasta_path="fasta_file.fasta")

Example annotation file for a TMT FragPipe experiment.

Description

Automatically created by FragPipe, manually checked by the user and input into the FragPipetoMSstatsPTMFormat converter. Requires the correct columns and maps the experimental desing into the MSstats format. Specify unique bioreplicates for group comparison designs, and the same bioreplicate for repeated measure designs. The columns and descriptions are below.

Usage

fragpipe_annotation

Format

A data.table with 7 columns.

Details

  • Run : Run name that matches exactly with FragPipe run. Used to join evidence and metadata in annotation file.

  • Fraction : If multiple fractions were used (i.e. the same mixture split into multiple fractions) enter that here. TechRepMixture : Multiple runs using the same bioreplicate

  • Channel : Mixture channel used

  • Condition : Name of condition that was used for each run.

  • Mixture : The unique mixture (plex) name

  • BioReplicate : Name of biological replicate. Repeating the same name here will tell MSstatsPTM that the experiment is a repeated measure design.

Examples

head(fragpipe_annotation)

Example annotation file for a global profiling run TMT FragPipe experiment.

Description

Automatically created by FragPipe, manually checked by the user and input into the FragPipetoMSstatsPTMFormat converter. Requires the correct columns and maps the experimental desing into the MSstats format. Specify unique bioreplicates for group comparison designs, and the same bioreplicate for repeated measure designs. The columns and descriptions are below.

Usage

fragpipe_annotation_protein

Format

A data.table with 7 columns.

Details

  • Run : Run name that matches exactly with FragPipe run. Used to join evidence and metadata in annotation file.

  • Fraction : If multiple fractions were used (i.e. the same mixture split into multiple fractions) enter that here. TechRepMixture : Multiple runs using the same bioreplicate

  • Channel : Mixture channel used

  • Condition : Name of condition that was used for each run.

  • Mixture : The unique mixture (plex) name

  • BioReplicate : Name of biological replicate. Repeating the same name here will tell MSstatsPTM that the experiment is a repeated measure design.

Examples

head(fragpipe_annotation_protein)

Output of FragPipe TMT PTM experiment

Description

This dataset was provided by the FragPipe team at the Nesvilab. It was processed using Philosopher and targeted Phosphorylation.

Usage

fragpipe_input

Format

A data.table with 29 columns and 246 rows.

Examples

head(fragpipe_input)

Output of FragPipe TMT global profiling experiment

Description

This dataset was provided by the FragPipe team at the Nesvilab. It was processed using Philosopher and targeted Phosphorylation.

Usage

fragpipe_input_protein

Format

A data.table with 27 columns and 47 rows.

Examples

head(fragpipe_input_protein)

Convert output of TMT labeled Fragpipe data into MSstatsPTM format.

Description

Takes as input TMT experiments which are the output of Fragpipe and converts into MSstatsPTM format. Requires msstats.csv file and an annotation file. Optionally an additional msstats.csv file can be uploaded if a corresponding global profiling run was performed. Site localization is performed and only high probability localizations are kept.

Usage

FragPipetoMSstatsPTMFormat(
  input,
  annotation = NULL,
  input_protein = NULL,
  annotation_protein = NULL,
  use_unmod_peptides = FALSE,
  label_type = "TMT",
  protein_id_col = "Protein",
  peptide_id_col = "Peptide.Sequence",
  mod_id_col = "STY",
  localization_cutoff = 0.75,
  remove_unlocalized_peptides = TRUE,
  Purity_cutoff = 0.6,
  PeptideProphet_prob_cutoff = 0.7,
  useUniquePeptide = TRUE,
  rmPSM_withfewMea_withinRun = FALSE,
  rmPeptide_OxidationM = TRUE,
  rmProtein_with1Feature = FALSE,
  summaryforMultipleRows = sum,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

input

data.frame of msstats.csv file produced by Philosopher

annotation

annotation with Run, Fraction, TechRepMixture, Mixture, Channel, BioReplicate, Condition columns or a path to file. Refer to the example 'annotation' for the meaning of each column. Channel column should be consistent with the channel columns (Ignore the prefix "Channel ") in msstats.csv file. Run column should be consistent with the Spectrum.File columns in msstats.csv file.

input_protein

same as input for global profiling run. Default is NULL.

annotation_protein

same as annotation for global profiling run. Default is NULL.

use_unmod_peptides

Boolean if the unmodified peptides in the input file should be used to construct the unmodified protein output. Only used if input_protein is not provided. Default is FALSE.

label_type

Type of labeling used for experiment. Must be one of "LF" or "TMT". Default is "TMT".

protein_id_col

Use 'Protein'(default) column for TMT. This needs to be changed to "ProteinName" for label free. For TMT, 'Master.Protein.Accessions' can be used instead to get the protein ID with single protein.

peptide_id_col

Use 'Peptide.Sequence'(default) column for TMT. Must be changed to "PeptideSequence" for label free. "Modified.Peptide.Sequence" can be used instead to get the modified peptide sequence.

mod_id_col

Column containing the modified Amino Acids. For example, a Phosphorylation experiment may pass STY. The corresponding column with STY combined with the mass (e.x. STY.79.9663) will be selected. Default is STY.

localization_cutoff

Minimum localization score required to keep modification. Default is .75.

remove_unlocalized_peptides

Boolean indicating if peptides without all sites localized should be kept. Default is TRUE (non-localized sites will be removed).

Purity_cutoff

Cutoff for purity. Default is 0.6. Purity refers to how much of the detected ion signal within a specific inclusion window belongs to the target molecule or its closely related forms, compared to any other unwanted signals or noise. Higher values indicate greater purity.

PeptideProphet_prob_cutoff

Cutoff for the peptide identification probability. Default is 0.7. The probability is confidence score determined by PeptideProphet and higher values indicate greater confidence.

useUniquePeptide

logical, if TRUE (default) removes peptides that are assigned for more than one proteins. We assume to use unique peptide for each protein.

rmPSM_withfewMea_withinRun

TRUE (default) will remove the features that have 1 or 2 measurements within each Run.

rmPeptide_OxidationM

TRUE (default) will remove the peptides including oxidation (M) sequence.

rmProtein_with1Feature

TRUE will remove the proteins which have only 1 peptide and charge. Defaut is FALSE.

summaryforMultipleRows

sum (default) or max - when there are multiple measurements for certain feature in certain run, select the feature with the largest summation or maximal value.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing wil be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

list of one or two data.frame of class MSstatsTMT, named PTM and PROTEIN

Examples

# TMT Example (with global profiling run)
head(fragpipe_input)
head(fragpipe_annotation)
head(fragpipe_input_protein)
head(fragpipe_annotation_protein)

msstats_data = FragPipetoMSstatsPTMFormat(fragpipe_input,
                                          fragpipe_annotation,
                                          fragpipe_input_protein, 
                                          fragpipe_annotation_protein,
                                          label_type="TMT",
                                          mod_id_col = "STY",
                                          localization_cutoff=.75,
                                          remove_unlocalized_peptides=TRUE)
head(msstats_data$PTM)
head(msstats_data$PROTEIN)

# LFQ Example (w/out global profiling run)
input = system.file("tinytest/raw_data/Fragpipe/MSstats.csv", 
                                        package = "MSstatsPTM")
input = data.table::fread(input)
annot = system.file("tinytest/raw_data/Fragpipe/experiment_annotation.tsv", 
                                        package = "MSstatsPTM")
annot = data.table::fread(annot)                                        

msstats_data = FragPipetoMSstatsPTMFormat(input,
                                          annot,
                                          label_type="LF",
                                          mod_id_col = "STY",
                                          localization_cutoff=.75,
                                          protein_id_col = "ProteinName",
                                          peptide_id_col = "PeptideSequence")
head(msstats_data$PTM)

# Note that this is NULL because we did not include a global profiling run.
# Ideally, you should include an independent global profiling run.
head(msstats_data$PROTEIN)

Visualization for model-based analysis and summarization

Description

To analyze the results of modeling changes in abundance of modified peptides and overall protein, groupComparisonPlotsPTM takes as input the results of the groupComparisonPTM function. It asses the results of three models: unadjusted PTM, adjusted PTM, and overall protein. To asses the results of the model, the following visualizations can be created: (1) VolcanoPlot (specify "VolcanoPlot" in option type), to plot peptides or proteins and their significance for each model. (2) Heatmap (specify "Heatmap" in option type), to evaluate the fold change between conditions and peptides/proteins

Usage

groupComparisonPlotsPTM(
  data = data,
  type,
  sig = 0.05,
  FCcutoff = FALSE,
  logBase.pvalue = 10,
  ylimUp = FALSE,
  ylimDown = FALSE,
  xlimUp = FALSE,
  x.axis.size = 10,
  y.axis.size = 10,
  dot.size = 3,
  text.size = 4,
  text.angle = 0,
  legend.size = 13,
  ProteinName = TRUE,
  colorkey = TRUE,
  numProtein = 50,
  width = 10,
  height = 10,
  which.Comparison = "all",
  which.PTM = "all",
  address = ""
)

Arguments

data

name of the list with models, which can be the output of the MSstatsPTM groupComparisonPTM function

type

choice of visualization, one of VolcanoPlot or Heatmap

sig

FDR cutoff for the adjusted p-values in heatmap and volcano plot. level of significance for comparison plot. 100(1-sig)% confidence interval will be drawn. sig=0.05 is default.

FCcutoff

For volcano plot or heatmap, whether involve fold change cutoff or not. FALSE (default) means no fold change cutoff is applied for significance analysis. FCcutoff = specific value means specific fold change cutoff is applied.

logBase.pvalue

for volcano plot or heatmap, (-) logarithm transformation of adjusted p-value with base 2 or 10(default).

ylimUp

for all three plots, upper limit for y-axis. FALSE (default) for volcano plot/heatmap use maximum of -log2 (adjusted p-value) or -log10 (adjusted p-value). FALSE (default) for comparison plot uses maximum of log-fold change + CI.

ylimDown

for all three plots, lower limit for y-axis. FALSE (default) for volcano plot/heatmap use minimum of -log2 (adjusted p-value) or -log10 (adjusted p-value). FALSE (default) for comparison plot uses minimum of log-fold change - CI.

xlimUp

for Volcano plot, the limit for x-axis. FALSE (default) for use maximum for absolute value of log-fold change or 3 as default if maximum for absolute value of log-fold change is less than 3.

x.axis.size

size of axes labels, e.g. name of the comparisons in heatmap, and in comparison plot. Default is 10.

y.axis.size

size of axes labels, e.g. name of targeted proteins in heatmap. Default is 10.

dot.size

size of dots in volcano plot and comparison plot. Default is 3.

text.size

size of ProteinName label in the graph for Volcano Plot. Default is 4.

text.angle

angle of x-axis labels represented each comparison at the bottom of graph in comparison plot. Default is 0.

legend.size

size of legend for color at the bottom of volcano plot. Default is 7.

ProteinName

for volcano plot only, whether display protein names or not. TRUE (default) means protein names, which are significant, are displayed next to the points. FALSE means no protein names are displayed.

colorkey

TRUE(default) shows colorkey.

numProtein

The number of proteins which will be presented in each heatmap. Default is 50.

width

width of the saved file. Default is 10.

height

height of the saved file. Default is 10.

which.Comparison

list of comparisons to draw plots. List can be labels of comparisons or order numbers of comparisons from levels(data$Label) , such as levels(testResultMultiComparisons$ComparisonResult$Label). Default is "all", which generates all plots for each protein.

which.PTM

Protein list to draw comparison plots. List can be names of Proteins or order numbers of Proteins from levels(testResultMultiComparisons$ComparisonResult$Protein). Default is "all", which generates all comparison plots for each protein.

address

the name of folder that will store the results. Default folder is the current working directory. The other assigned folder has to be existed under the current working directory. An output pdf file is automatically created with the default name of "VolcanoPlot.pdf" or "Heatmap.pdf". The command address can help to specify where to store the file as well as how to modify the beginning of the file name. If address=FALSE, plot will be not saved as pdf file but showed in window

Value

plot or pdf

Examples

model.lf.msstatsptm = groupComparisonPTM(summary.data, 
                                     data.type = "LabelFree")
groupComparisonPlotsPTM(data = model.lf.msstatsptm,
                        type = "VolcanoPlot",
                        FCcutoff= 2,
                        logBase.pvalue = 2,
                        address=FALSE)

Perform differential analysis on MS-based proteomics experiments targeting PTMs

Description

Takes summarized PTM and protein data from dataSummarizationPTM or dataSummarizationPTM_TMT functions and performs differential analysis. Leverages unmodified protein data to perform adjustment and deconvolute the effect of the PTM and unmodified protein. If protein data is unavailable, PTM data can still be passed into the function, however adjustment can not be performed. All model results are returned for completeness.

Usage

groupComparisonPTM(
  data,
  data.type,
  contrast.matrix = "pairwise",
  moderated = FALSE,
  adj.method = "BH",
  log_base = 2,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL,
  base = "MSstatsPTM_log_"
)

Arguments

data

list of summarized datasets. Output of MSstatsPTM summarization function dataSummarizationPTM or dataSummarizationPTM_TMT depending on acquisition type.

data.type

string indicating experimental acquisition type. "TMT" is used for TMT labeled experiments. For all other experiments (Label Free/ DDA/ DIA) use "LabelFree".

contrast.matrix

comparison between conditions of interests. Default models full pairwise comparison between all conditions

moderated

For TMT experiments only. TRUE will moderate t statistic; FALSE (default) uses ordinary t statistic. Default is FALSE.

adj.method

For TMT experiemnts only. Adjusted method for multiple comparison. "BH" is default. "BH" is used for all other experiment types

log_base

For non-TMT experiments only. The base of the logarithm used in summarization.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing will be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If append = TRUE, has to be a valid path to a file.

base

start of the file name.

Value

list of modeling results. Includes PTM, PROTEIN, and ADJUSTED data.tables with their corresponding model results.

Examples

model.lf.msstatsptm = groupComparisonPTM(summary.data, 
                                     data.type = "LabelFree",
                                     verbose = FALSE)

Locate modified sites with a peptide

Description

locateMod locates modified sites with a peptide.

Usage

locateMod(peptide, aaStart, residueSymbol)

Arguments

peptide

A string. Peptide sequence.

aaStart

An integer. Starting index of the peptide.

residueSymbol

A string. Modification residue and denoted symbol.

Value

A string.

Examples

locateMod("P*EP*TIDE", 3, "\\*")

Annotate modified sites with associated peptides

Description

PTMlocate annotates modified sites with associated peptides.

Usage

locatePTM(peptide, uniprot, fasta, modResidue, modSymbol, rmConfound = FALSE)

Arguments

peptide

A string vector of peptide sequences. The peptide sequence does not include its preceding and following AAs.

uniprot

A string vector of Uniprot identifiers of the peptides' originating proteins. UniProtKB entry isoform sequence is used.

fasta

A data.table with FASTA information. Output of tidyFasta.

modResidue

A string. Modifiable amino acid residues.

modSymbol

A string. Symbol of a modified site.

rmConfound

A logical. TRUE removes confounded unmodified sites, FALSE otherwise. Default is FALSE.

Value

A data frame with three columns: uniprot_iso, peptide, site.

Examples

fasta = tidyFasta(system.file("extdata", "O13297.fasta", package="MSstatsPTM"))
locatePTM("DRVSYIHNDSC*TR", "O13297", fasta, "C", "\\*")

Example annotation file for a label-free MaxQuant experiment.

Description

Must be manually created by the user and input into the MaxQtoMSstatsPTMFormat converter. Requires the correct columns and maps the experimental desing into the MSstats format. Specify unique bioreplicates for group comparison designs, and the same bioreplicate for repeated measure designs. The columns and descriptions are below.

Usage

maxq_lf_annotation

Format

A data.table with 5 columns.

Details

  • Run : Run name that matches exactly with MaxQuant run. Used to join evidence and metadata in annotation file.

  • Condition : Name of condition that was used for each run.

  • BioReplicate : Name of biological replicate. Repeating the same name here will tell MSstatsPTM that the experiment is a repeated measure design.

  • Raw.file : Run name that matches exactly with MaxQuant run. Used to join evidence and metadata in annotation file.

  • IsotopeLabelType: Name of isotope label. May be all L or unique depending on experimental design.

Examples

head(maxq_lf_annotation)

Example MaxQuant evidence file from the output of a label free experiment

Description

Experiment was performed by the Olsen lab and published on Nat. Commun. (citation below).

Usage

maxq_lf_evidence

Format

a data.table with 63 columns and 511 rows, the output of MaxQuant

Details

Bekker-Jensen, D.B., Bernhardt, O.M., Hogrebe, A. et al. Rapid and site-specific deep phosphoproteome profiling by data-independent acquisition without the need for spectral libraries. Nat Commun 11, 787 (2020). https://doi.org/10.1038/s41467-020-14609-1

The experiment was processed using MaxQuant by the computational proteomics team at Pfizer (Liang Xue and Pierre Jean).

The experiment did not contain a global profiling run, but we show an example of extracting the unmodified peptides and using them in place of the profiling run.

Examples

head(maxq_lf_evidence)

Example annotation file for a TMT MaxQuant experiment.

Description

Must be manually created by the user and input into the MaxQtoMSstatsPTMFormat converter. Requires the correct columns and maps the experimental desing into the MSstats format. Specify unique bioreplicates for group comparison designs, and the same bioreplicate for repeated measure designs. The columns and descriptions are below.

Usage

maxq_tmt_annotation

Format

A data.table with 7 columns.

Details

  • Run : Run name that matches exactly with MaxQuant run. Used to join evidence and metadata in annotation file.

  • Fraction : If multiple fractions were used (i.e. the same mixture split into multiple fractions) enter that here. TechRepMixture : Multiple runs using the same bioreplicate

  • Channel : Mixture channel used

  • Condition : Name of condition that was used for each run.

  • Mixture : The unique mixture (plex) name

  • BioReplicate : Name of biological replicate. Repeating the same name here will tell MSstatsPTM that the experiment is a repeated measure design.

Examples

head(maxq_tmt_annotation)

Example MaxQuant evidence file from the output of a TMT experiment

Description

Experiment was performed by the Olsen lab and published on Nat. Commun. (citation below).

Usage

maxq_tmt_evidence

Format

a data.table with 96 columns and 199 rows, the output of MaxQuant

Details

Hogrebe, A., von Stechow, L., Bekker-Jensen, D.B. et al. Benchmarking common quantification strategies for large-scale phosphoproteomics. Nat Commun 9, 1045 (2018). https://doi.org/10.1038/s41467-018-03309-6

The experiment was processed using MaxQuant by the computational proteomics team at Pfizer (Liang Xue and Pierre Jean).

The experiment did not contain a global profiling run, but we show an example of extracting the unmodified peptides and using them in place of the profiling run.

Examples

head(maxq_tmt_evidence)

Convert output of label-free or TMT MaxQuant experiments into MSstatsPTM format

Description

Takes as input LF/TMT experiments from MaxQ and converts the data into the format needed for MSstatsPTM. Requires modified evidence.txt file from MaxQ and an annotation file for PTM data. To adjust modified peptides for changes in global protein level, unmodified TMT experimental data must also be returned. Optionally can use ⁠Phospho(STY)Sites.txt⁠ (or other PTM specific files) from MaxQuant, but this is not recommended. If PTM specific file provided, the raw intensities must be provided, not a ratio.

Usage

MaxQtoMSstatsPTMFormat(
  evidence = NULL,
  annotation = NULL,
  fasta_path,
  fasta_protein_name = "uniprot_ac",
  mod_id = "\\(Phospho \\(STY\\)\\)",
  sites_data = NULL,
  evidence_prot = NULL,
  proteinGroups = NULL,
  annotation_protein = NULL,
  use_unmod_peptides = FALSE,
  labeling_type = "LF",
  mod_num = "Single",
  TMT_keyword = "TMT",
  ptm_keyword = "phos",
  which_proteinid_ptm = "Proteins",
  which_proteinid_protein = "Proteins",
  remove_other_mods = TRUE,
  removeMpeptides = FALSE,
  removeOxidationMpeptides = FALSE,
  removeProtein_with1Peptide = FALSE,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

evidence

name of 'evidence.txt' data, which includes feature-level data for enriched (PTM) data.

annotation

data frame annotation file for the ptm level data. Contains column Run, Fraction, TechRepMixture, Mixture, Channel, BioReplicate, Condition.

fasta_path

A string of path to a FASTA file, used to match PTM peptides.

fasta_protein_name

Name of fasta column that matches with protein name in evidence file. Default is uniprot_ac.

mod_id

Character that indicates the modification of interest. Default is ⁠\\(Phospho\\)⁠. Note ⁠\\⁠ must be included before special characters.

sites_data

(Not recommended. Only used if evidence file not provided. Only works for TMT labeled data) Modified peptide output from MaxQuant. For example, a phosphorylation experiment would require the Phospho(STY)Sites.txt file

evidence_prot

name of 'evidence.txt' data, which includes feature-level data for global profiling (unmodified) data.

proteinGroups

name of 'proteinGroups.txt' data. It needs to matching protein group ID in evidence_prot.

annotation_protein

data frame annotation file for the protein level data. Contains column Run, Fraction, TechRepMixture, Mixture, Channel, BioReplicate, Condition.

use_unmod_peptides

Boolean if the unmodified peptides in the input file should be used to construct the unmodified protein output. Only used if input_protein is not provided. Default is FALSE.

labeling_type

Either TMT or LF (Label-Free) depending on experimental design. Default is LF.

mod_num

(Only if sites.data is used) For modified peptide dataset. The number modifications per peptide to be used. If "Single", only peptides with one modification will be used. Otherwise "Total" can be selected which does not cap the number of modifications per peptide. "Single" is the default. Selecting "Total" may confound the effect of different modifications.

TMT_keyword

(Only if sites.data is used) the sub-name of columns in sites.data file. Default is TMT. This corresponds to the columns in the format Reporter.intensity.corrected.1.TMT1phos___1. Specifically, this parameter indicates the first section of the string TMT1phos (Before the mixture number). If TMT is present in the string, set this value to TMT. Else if TMT is not there (ie string is in the format ⁠1phos⁠) leave this parameter as an empty string (”).

ptm_keyword

(Only if sites.data is used) the sub-name of columns in the sites.data file. Default is phos. This corresponds to the columns in the format Reporter.intensity.corrected.1.TMT1phos___1. Specifically, this parameter indicates the second section of the string TMT1phos (After the mixture number). If the string is present, set this parameter. Else if this part of the string is empty (ie string is in the format TMT1) leave this parameter as an empty string (”).

which_proteinid_ptm

For PTM dataset, which column to use for protein name. Use 'Proteins'(default) column for protein name. 'Leading.proteins' or 'Leading.razor.protein' or 'Gene.names' can be used instead to get the protein ID with single protein. However, those can potentially have the shared peptides.

which_proteinid_protein

For Protein dataset, which column to use for protein name. Same options as above.

remove_other_mods

Remove peptides which include modfications other than the one listed in mod_id. Default is TRUE. For example, in an experiment targeting Phosphorylation, setting this parameter to TRUE would remove peptides like (Acetyl (Protein N-term))AAAAPDSRVS(Phospho (STY))EEENLK. Set this parameter to FALSE to keep peptides with extraneous modifications.

removeMpeptides

If Oxidation (M) modifications should be removed. Default is TRUE.

removeOxidationMpeptides

TRUE will remove the peptides including 'oxidation (M)' in modification. FALSE is default.

removeProtein_with1Peptide

TRUE will remove the proteins which have only 1 peptide and charge. FALSE is default.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing wil be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

a list of two data.tables named 'PTM' and 'PROTEIN' in the format required by MSstatsPTM.

Examples

# TMT experiment
head(maxq_tmt_evidence)
head(maxq_tmt_annotation)

msstats_format_tmt = MaxQtoMSstatsPTMFormat(evidence=maxq_tmt_evidence,
                        annotation=maxq_tmt_annotation,
                        fasta=system.file("extdata", "maxq_tmt_fasta.fasta", package="MSstatsPTM"),
                        fasta_protein_name="uniprot_ac",
                        mod_id="\\(Phospho \\(STY\\)\\)",
                        use_unmod_peptides=TRUE,
                        labeling_type = "TMT",
                        which_proteinid_ptm = "Proteins")

head(msstats_format_tmt$PTM)
head(msstats_format_tmt$PROTEIN)

# LF experiment
head(maxq_lf_evidence)
head(maxq_lf_annotation)

msstats_format_lf = MaxQtoMSstatsPTMFormat(evidence=maxq_lf_evidence,
                        annotation=maxq_lf_annotation,
                        fasta=system.file("extdata", "maxq_lf_fasta.fasta", package="MSstatsPTM"),
                        fasta_protein_name="uniprot_ac",
                        mod_id="\\(Phospho \\(STY\\)\\)",
                        use_unmod_peptides=TRUE,
                        labeling_type = "LF",
                        which_proteinid_ptm = "Proteins")
head(msstats_format_lf$PTM)
head(msstats_format_lf$PROTEIN)

Import Metamorpheus files into PTM format

Description

Import Metamorpheus files into PTM format

Usage

MetamorpheusToMSstatsPTMFormat(
  input,
  annotation,
  fasta_path,
  input_protein = NULL,
  annotation_protein = NULL,
  use_unmod_peptides = FALSE,
  mod_ids = c("\\[Common Biological:Phosphorylation on S\\]"),
  useUniquePeptide = TRUE,
  removeFewMeasurements = TRUE,
  removeProtein_with1Feature = FALSE,
  summaryforMultipleRows = max,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

input

name of Metamorpheus output file, which is tabular format. Use the AllQuantifiedPeaks.tsv file from the Metamorpheus output.

annotation

name of 'annotation.txt' data which includes Condition, BioReplicate.

fasta_path

string containing path to the corresponding fasta file for the modified peptide dataset.

input_protein

same as input for global profiling run. Default is NULL.

annotation_protein

same as annotation for global profiling run. Default is NULL.

use_unmod_peptides

If protein_input is not provided, unmodified peptides can be extracted from input to be used in place of a global profiling run. Default is FALSE.

mod_ids

List of modifications of interest. Default is a list with only ⁠Common Biological:Phosphorylation on S⁠. Please note that the 'mod_ids' parameter currently supports lists of size 1 only. Future updates aim to extend its functionality to accommodate lists of greater sizes. Note ⁠\\⁠ must be included before special characters.

useUniquePeptide

TRUE (default) removes peptides that are assigned for more than one proteins. We assume to use unique peptide for each protein.

removeFewMeasurements

TRUE (default) will remove the features that have 1 or 2 measurements across runs.

removeProtein_with1Feature

TRUE will remove the proteins which have only 1 feature, which is the combination of peptide, precursor charge, fragment and charge. FALSE is default.

summaryforMultipleRows

max(default) or sum - when there are multiple measurements for certain feature and certain run, use highest or sum of multiple intensities.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing wil be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

a list of two data.tables named 'PTM' and 'PROTEIN' in the format required by MSstatsPTM.

Author(s)

Anthony Wu

Examples

input = system.file("tinytest/raw_data/Metamorpheus/AllQuantifiedPeaks.tsv", 
                                package = "MSstatsPTM")
input = data.table::fread(input)
annot = system.file("tinytest/raw_data/Metamorpheus/ExperimentalDesign.tsv", 
                                package = "MSstatsPTM")
annot = data.table::fread(annot)
input_protein = system.file("tinytest/raw_data/Metamorpheus/AllQuantifiedPeaksGlobalProteome.tsv",
                                package = "MSstatsPTM")
input_protein = data.table::fread(input_protein)
annot_protein = system.file("tinytest/raw_data/Metamorpheus/ExperimentalDesignGlobalProteome.tsv", 
                                package = "MSstatsPTM")
annot_protein = data.table::fread(annot_protein)
fasta_path=system.file("extdata", "metamorpheus_fasta.fasta", 
                                package="MSstatsPTM")
metamorpheus_imported = MetamorpheusToMSstatsPTMFormat(
    input, 
    annot, 
    fasta_path=fasta_path,
    input_protein=input_protein,
    annotation_protein=annot_protein,
    use_unmod_peptides=FALSE,
    mod_ids = c("\\[Common Fixed:Carbamidomethyl on C\\]")
)
head(metamorpheus_imported$PTM)
head(metamorpheus_imported$PROTEIN)

MSstatsPTM: A package for detecting differentially abundant post-translational modifications (PTM) in mass spectrometry-based proteomic experiments.

Description

A set of tools for detecting differentially abundant PTMs and proteins in shotgun mass spectrometry-based proteomic experiments. The package can handle a variety of acquisition types, including label free and TMT experiments, acquired with DDA, DIA, SRM or PRM acquisition methods. The package includes tools to convert raw data from different spectral processing tools, summarize feature intensities, and fit a linear mixed effects model. A major advantage of the package is to leverage a separate global profiling run and adjust the PTM fold change for changes in the unmodified protein, showing the unconvoluted PTM fold change. Finally, the package includes functionality to plot a variety of data visualizations.

functions

  • FragPipetoMSstatsPTMFormat : Generates MSstatsPTM required input format for TMT FragePipe outputs.

  • MaxQtoMSstatsPTMFormat : Generates MSstatsPTM required input format for label-free and TMT MaxQuant outputs.

  • ProgenesistoMSstatsPTMFormat : Generates MSstatsPTM required input format for label-free Progenesis outputs.

  • SpectronauttoMSstatsPTMFormat : Generates MSstatsPTM required input format for label-free Spectronaut outputs.

  • SkylinetoMSstatsPTMFormat : Generates MSstatsPTM required input format for Skyline outputs.

  • PStoMSstatsPTMFormat : Generates MSstatsPTM required input format for PEAKS outputs.

  • PDtoMSstatsPTMFormat : Generates MSstatsPTM required input format for Proteome Discoverer outputs.

  • dataSummarizationPTM : Summarizes PSM level quantification to peptide (modification) and protein level quantification. For use in label-free analysis

  • dataSummarizationPTM_TMT : Summarizes PSM level quantification to peptide (modification) and protein level quantification. For use in TMT analysis.

  • dataProcessPlotsPTM : Visualization for explanatory data analysis. Specifically gives ability to plot Profile and Quality Control plots.

  • groupComparisonPTM : Tests for significant changes in PTM and protein abundance across conditions. Adjusts PTM fold change for changes in protein abundance.

  • groupComparisonPlotsPTM : Visualization for model-based analysis and summarization


Locate modification site number and amino acid

Description

Locate modification site number and amino acid

Usage

MSstatsPTMSiteLocator(
  data,
  protein_name_col = "ProteinName",
  unmod_pep_col = "PeptideSequence",
  mod_pep_col = "PeptideModifiedSequence",
  clean_mod = FALSE,
  fasta_file = NULL,
  fasta_protein_name = "header",
  mod_id = "\\*",
  localization_scores = FALSE,
  localization_cutoff = 0.75,
  remove_unlocalized_peptides = TRUE,
  terminus_included = FALSE,
  terminus_id = "\\.",
  mod_id_is_numeric = FALSE,
  remove_underscores = FALSE,
  remove_other_mods = FALSE,
  bracket = FALSE,
  replace_text = FALSE
)

Arguments

data

data.table of enriched experimental run. Must include ProteinName, PeptideSequence, PeptideModifiedSequence, and (optionally) Start columns.

protein_name_col

Name of column indicating protein. Default is ProteinName.

unmod_pep_col

Name of column indicating unmodified peptide sequence. Default is PeptideSequence.

mod_pep_col

Name of column indicating modified peptide sequence. Default is PeptideModifiedSequence.

clean_mod

Remove special characters and numbers around modification name. Default is FALSE

fasta_file

File path to FASTA file that matches with proteins in data. Can be either string or data.table processed with tidyFasta() function. Default to NULL if peptide number included in data.

fasta_protein_name

Name of fasta file column that matches with protein_name_col. Default is header.

mod_id

String that indicates what amino acid was modified in PeptideSequence.

localization_scores

Boolean indicating if mod id is a localization score. If TRUE, mod_id will be ignored and localization cutoff will be used to determine sites. Default is FALSE.

localization_cutoff

Default is .75. Localization probabilities below cutoffs will be removed. localization_scores must be TRUE.

remove_unlocalized_peptides

Default is TRUE. If localization_scores is TRUE and probabilities are below localization_cutoff, the modification site will not be able to be determined. These unlocalized peptides can be kept or removed. If FALSE the unlocalized peptides will still be used in modeling the sites that could be localized.

terminus_included

Boolean indicating if the PeptideSequence includes the terminus amino acid.

terminus_id

String that indicates what the terminus amino acid is. Default is '.'.

mod_id_is_numeric

Boolean indicating if modification identifier is a number instead of a character (i.e. +80 vs *).

remove_underscores

Boolean indicating if underscores around peptide exist. These should be removed to properly count where in sequence the modification occurred.

remove_other_mods

keeping mods that are not of interest can mess up the amino acid count. Remove them if they are causing issues.

bracket

bracket type that encompasses PTM (usually [ or (). Always pass opening bracket (there is a function to grab the close bracket). Default is FALSE (i.e. no bracket).

replace_text

If PTM is noted by text (i.e. Phospho) and needs to be replaced by an indicator (*)

Value

data.table with site location added into Protein column.

Examples

##TODO

Example annotation file for a label-free Proteome Discoverer experiment.

Description

Must be manually created by the user and input into the PDtoMSstatsPTMFormat converter. Requires the correct columns and maps the experimental desing into the MSstats format. Specify unique bioreplicates for group comparison designs, and the same bioreplicate for repeated measure designs. The columns and descriptions are below.

Usage

pd_annotation

Format

A data.table with 3 columns.

Details

  • Run : Run name that matches exactly with PD run. Used to join evidence and metadata in annotation file.

  • Condition : Name of condition that was used for each run.

  • BioReplicate : Name of biological replicate. Repeating the same name here will tell MSstatsPTM that the experiment is a repeated measure design.

Examples

head(pd_annotation)

Example Proteome Discoverer evidence file from the output of a label free experiment

Description

Experiment was performed by the Olsen lab and published on Nat. Commun. (citation below).

Usage

pd_psm_input

Format

a data.table with 60 columns and 1657 rows, the output of PD

Details

Bekker-Jensen, D.B., Bernhardt, O.M., Hogrebe, A. et al. Rapid and site-specific deep phosphoproteome profiling by data-independent acquisition without the need for spectral libraries. Nat Commun 11, 787 (2020). https://doi.org/10.1038/s41467-020-14609-1

The experiment was processed using Proteome Discoverer by the computational proteomics team at Pfizer (Liang Xue and Pierre Jean).

The experiment did not contain a global profiling run, but we show an example of extracting the unmodified peptides and using them in place of the profiling run.

Examples

head(pd_psm_input)

Example output of Proteome Discoverer converter

Description

output using example data provided in package

Usage

pd_testing_output

Format

a list with 2 data.frames

Details

The experiment did not contain a global profiling run, but we show an example of extracting the unmodified peptides and using them in place of the profiling run.

Examples

head(pd_testing_output)

Convert Proteome Discoverer output into MSstatsPTM format

Description

Import Proteome Discoverer files, identify modification site location.

Usage

PDtoMSstatsPTMFormat(
  input,
  annotation,
  fasta_path,
  protein_input = NULL,
  annotation_protein = NULL,
  labeling_type = "LF",
  mod_id = "\\(Phospho\\)",
  use_localization_cutoff = FALSE,
  keep_all_mods = FALSE,
  use_unmod_peptides = FALSE,
  fasta_protein_name = "uniprot_iso",
  localization_cutoff = 75,
  remove_unlocalized_peptides = TRUE,
  useNumProteinsColumn = FALSE,
  useUniquePeptide = TRUE,
  summaryforMultipleRows = max,
  removeFewMeasurements = TRUE,
  removeOxidationMpeptides = FALSE,
  removeProtein_with1Peptide = FALSE,
  which_quantification = "Precursor.Area",
  which_proteinid = "Protein.Group.Accessions",
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

input

PD report corresponding with enriched experimental data.

annotation

name of 'annotation.txt' or 'annotation.csv' data which includes Condition, BioReplicate, Run information. 'Run' will be matched with 'Spectrum.File'

fasta_path

string containing path to the corresponding fasta file for the modified peptide dataset.

protein_input

PD report corresponding with unmodified experimental data.

annotation_protein

Same format as annotation corresponding to unmodified data.

labeling_type

type of experimental design, must be one of LF for label free or TMT for tandem mass tag.

mod_id

Character that indicates the modification of interest. Default is ⁠\\(Phospho\\)⁠. Note ⁠\\⁠ must be included before special characters.

use_localization_cutoff

Boolean indicating whether to use a custom localization cutoff or rely on PD's modifications column. TRUE is default and apply custom cutoff localization_cutoff.

keep_all_mods

Boolean indicating whether to keep or remove peptides not in mod_id. Default is FALSE.

use_unmod_peptides

If protein_input is not provided, unmodified peptides can be extracted from input to be used in place of a global profiling run. Default is FALSE.

fasta_protein_name

Name of fasta column that matches with protein name in evidence file. Default is uniprot_iso.

localization_cutoff

Minimum localization score required to keep modification. Default is .75.

remove_unlocalized_peptides

Boolean indicating if peptides without all sites localized should be kept. Default is TRUE (non-localized sites will be removed).

useNumProteinsColumn

TRUE removes peptides which have more than 1 in Proteins column of PD output.

useUniquePeptide

TRUE (default) removes peptides that are assigned for more than one proteins. We assume to use unique peptide for each protein.

summaryforMultipleRows

max(default) or sum - when there are multiple measurements for certain feature and certain run, use highest or sum of multiple intensities.

removeFewMeasurements

TRUE (default) will remove the features that have 1 or 2 measurements across runs.

removeOxidationMpeptides

TRUE will remove the peptides including 'oxidation (M)' in modification. FALSE is default.

removeProtein_with1Peptide

TRUE will remove the proteins which have only 1 peptide and charge. FALSE is default.

which_quantification

Use 'Precursor.Area'(default) column for quantified intensities. 'Intensity' or 'Area' can be used instead.

which_proteinid

Use 'Protein.Accessions'(default) column for protein name. 'Master.Protein.Accessions' can be used instead.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing will be printed to the console

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

list of data.table

Examples

head(pd_psm_input)
head(pd_annotation)

msstats_format = PDtoMSstatsPTMFormat(pd_psm_input, 
                                      pd_annotation, 
                                      system.file("extdata", "pd_fasta.fasta", package="MSstatsPTM"),
                                      use_unmod_peptides=TRUE, 
                                      which_proteinid = "Master.Protein.Accessions")

head(msstats_format$PTM)
head(msstats_format$PROTEIN)

Converts non-TMT Progenesis output into the format needed for MSstatsPTM

Description

Converts non-TMT Progenesis output into the format needed for MSstatsPTM

Usage

ProgenesistoMSstatsPTMFormat(
  ptm_input,
  annotation,
  global_protein_input = FALSE,
  fasta_path = FALSE,
  useUniquePeptide = TRUE,
  summaryforMultipleRows = max,
  removeFewMeasurements = TRUE,
  removeOxidationMpeptides = FALSE,
  removeProtein_with1Peptide = FALSE,
  mod.num = "Single"
)

Arguments

ptm_input

name of Progenesis output with modified peptides, which is wide-format. 'Accession', Sequence', 'Modification', 'Charge' and one column for each run are required

annotation

name of 'annotation.txt' or 'annotation.csv' data which includes Condition, BioReplicate, Run, and Type (PTM or Protein) information. It will be matched with the column name of input for MS runs. Please note PTM and global Protein run names are often different, which is why an additional Type column indicating Protein or PTM is required.

global_protein_input

name of Progenesis output with unmodified peptides, which is wide-format. 'Accession', Sequence', 'Modification', 'Charge' and one column for each run are required

fasta_path

string containing path to the corresponding fasta file for the modified peptide dataset.

useUniquePeptide

TRUE(default) removes peptides that are assigned for more than one proteins. We assume to use unique peptide for each protein.

summaryforMultipleRows

max(default) or sum - when there are multiple measurements for certain feature and certain run, use highest or sum of multiple intensities.

removeFewMeasurements

TRUE (default) will remove the features that have 1 or 2 measurements across runs.

removeOxidationMpeptides

TRUE will remove the modified peptides including 'Oxidation (M)' sequence. FALSE is default.

removeProtein_with1Peptide

TRUE will remove the proteins which have only 1 peptide and charge. FALSE is default.

mod.num

For modified peptide dataset, must be one of Single or Total. The default is Single. The number modifications per peptide to be used. If "Single", only peptides with one modification will be used. Otherwise "Total" includes peptides with more than one modification. Selecting "Total" may confound the effect of different modifications.

Value

a list of two data.tables named 'PTM' and 'PROTEIN' in the format required by MSstatsPTM.

Examples

input = system.file("tinytest/raw_data/Progenesis/progenesis_peptide.csv", 
                                package = "MSstatsPTM")
input = data.table::fread(input)
colnames(input) = unlist(input[1,])
input = input[-1,]
annot = system.file("tinytest/raw_data/Progenesis/phospho_annotation.csv", 
                                package = "MSstatsPTM")
annot = data.table::fread(annot)
prog_imported = ProgenesistoMSstatsPTMFormat(
    input, 
    annot
)
head(prog_imported$PTM)

Convert Peaks Studio output into MSstatsPTM format

Description

Currently only supports label-free quantification.

Usage

PStoMSstatsPTMFormat(
  input,
  annotation,
  input_protein = NULL,
  annotation_protein = NULL,
  use_unmod_peptides = FALSE,
  target_modification = NULL,
  remove_oxidation_peptides = FALSE,
  remove_multi_mod_types = FALSE,
  summaryforMultipleRows = max,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

input

name of Peaks Studio PTM output

annotation

name of annotation file which includes Raw.file, Condition, BioReplicate, Run. For example annotation see example below.

input_protein

name of Peaks Studio unmodified protein output (optional)

annotation_protein

name of annotation file which includes Raw.file, Condition, BioReplicate, Run for unmodified protein output.

use_unmod_peptides

Boolean if the unmodified peptides in the input file should be used to construct the unmodified protein output. Only used if input_protein is not provided. Default is FALSE

target_modification

Character name of modification of interest. To use all mod types, leave as NULL. Default is NULL. Note that if the name includes special characters, you must include "\" before the characters. Ex. "Phosphorylation \(STY\)"

remove_oxidation_peptides

Boolean if Oxidation (M) modifications should be removed. Default is FALSE

remove_multi_mod_types

Used if target_modification is not NULL. TRUE will remove peptides with multiple types of modifications (ie acetylation and phosphorylation). FALSE will keep these peptides and summarize them seperately.

summaryforMultipleRows

max(default) or sum - when there are multiple measurements for certain feature and certain run, use highest or sum of multiple intensities.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing wil be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

list of data.table

Examples

# The output should be in the following format.
head(raw.input$PTM)
head(raw.input$PROTEIN)

Example of input PTM dataset for LabelFree/DDA/DIA experiments.

Description

It can be the output of MSstatsPTM converter ProgenesistoMSstatsPTMFormat or other MSstats converter functions (Please see MSstatsPTM_LabelFree_Workflow vignette). The dataset is formatted as a list with two data.tables named PTM and PROTEIN. In each data.table the variables are as follows:

Usage

raw.input

Format

A list of two data.tables named PTM and PROTEIN with 1745 and 478 rows respectively.

Details

#'

  • ProteinName : Name of protein with modification site mapped in with an underscore. ie "Protein_4_Y474"

  • PeptideSequence

  • Condition : Condition (ex. Healthy, Cancer, Time0)

  • BioReplicate : Unique ID for biological subject.

  • Run : MS run ID.

  • Intensity

  • PrecursorCharge

  • FragmentIon

  • ProductCharge

  • IsotopeLabelType

Examples

head(raw.input$PTM)
head(raw.input$PROTEIN)

Example of input PTM dataset for TMT experiments.

Description

It can be the output of MSstatsPTM converter MaxQtoMSstatsPTMFormat or other MSstatsTMT converter functions (Please see MSstatsPTM_TMT_Workflow vignette). The dataset is formatted as a list with two data.tables named PTM and PROTEIN. In each data.table the variables are as follows:

Usage

raw.input.tmt

Format

A list of two data.tables named PTM and PROTEIN with 1716 and 29221 rows respectively.

Details

  • ProteinName : Name of protein with modification site mapped in with an underscore. ie "Protein_4_Y474"

  • PeptideSequence

  • Charge

  • PSM

  • Mixture : Mixture of samples labeled with different TMT reagents, which can be analyzed in a single mass spectrometry experiment. If the channal doesn't have sample, please add ⁠Empty' under Condition. \item TechRepMixture : Technical replicate of one mixture. One mixture may have multiple technical replicates. For example, if ⁠TechRepMixture' = 1, 2 are the two technical replicates of one mixture, then they should match with same ⁠Mixture' value. \item Run : MS run ID. \item Channel : Labeling information (126, ... 131). \item Condition : Condition (ex. Healthy, Cancer, Time0) \item BioReplicate : Unique ID for biological subject. If the channal doesn't have sample, please add ⁠Empty' under BioReplicate.

  • Intensity

Examples

head(raw.input.tmt$PTM)
head(raw.input.tmt$PROTEIN)

Convert Skyline output into MSstatsPTM format

Description

Currently only supports label-free quantification.

Usage

SkylinetoMSstatsPTMFormat(
  input,
  fasta_path,
  fasta_protein_name = "uniprot_iso",
  annotation = NULL,
  input_protein = NULL,
  annotation_protein = NULL,
  use_unmod_peptides = FALSE,
  removeiRT = TRUE,
  filter_with_Qvalue = TRUE,
  qvalue_cutoff = 0.01,
  use_unique_peptide = TRUE,
  remove_few_measurements = FALSE,
  remove_oxidation_peptides = FALSE,
  removeProtein_with1Feature = FALSE,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

input

name of Skyline PTM output

fasta_path

A string of path to a FASTA file, used to match PTM peptides.

fasta_protein_name

Name of fasta column that matches with protein name in evidence file. Default is uniprot_iso.

annotation

name of 'annotation.txt' data which includes Condition, BioReplicate, Run. If annotation is already complete in Skyline, use annotation=NULL (default). It will use the annotation information from input.

input_protein

name of Skyline unmodified protein output (optional)

annotation_protein

name of 'annotation.txt' data which includes Condition, BioReplicate, Run for unmodified protein output. This can be the same as annotation.

use_unmod_peptides

Boolean if the unmodified peptides in the input file should be used to construct the unmodified protein output. Only used if input_protein is not provided. Default is FALSE.

removeiRT

TRUE (default) will remove the proteins or peptides which are labeld 'iRT' in 'StandardType' column. FALSE will keep them.

filter_with_Qvalue

TRUE(default) will filter out the intensities that have greater than qvalue_cutoff in DetectionQValue column. Those intensities will be replaced with zero and will be considered as censored missing values for imputation purpose.

qvalue_cutoff

Cutoff for DetectionQValue. default is 0.01.

use_unique_peptide

TRUE (default) removes peptides that are assigned for more than one proteins. We assume to use unique peptide for each protein.

remove_few_measurements

TRUE will remove the features that have 1 or 2 measurements across runs. FALSE is default.

remove_oxidation_peptides

TRUE will remove the peptides including 'oxidation (M)' in modification. FALSE is default.

removeProtein_with1Feature

TRUE will remove the proteins which have only 1 feature, which is the combination of peptide, precursor charge, fragment and charge. FALSE is default.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing wil be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

list of data.table

Examples

# The output should be in the following format.
head(raw.input$PTM)
head(raw.input$PROTEIN)

Example annotation file for a label-free Spectronaut experiment.

Description

Must be manually created by the user and input into the SpectronauttoMSstatsPTMFormat converter. Requires the correct columns and maps the experimental desing into the MSstats format. Specify unique bioreplicates for group comparison designs, and the same bioreplicate for repeated measure designs. The columns and descriptions are below.

Usage

spectronaut_annotation

Format

A data.table with 5 columns.

Details

  • Run : Run name that matches exactly with Spectronaut run. Used to join evidence and metadata in annotation file.

  • Condition : Name of condition that was used for each run.

  • BioReplicate : Name of biological replicate. Repeating the same name here will tell MSstatsPTM that the experiment is a repeated measure design.

  • Raw.file : Run name that matches exactly with Spectronaut run. Used to join evidence and metadata in annotation file.

Examples

head(spectronaut_annotation)

Example Spectronaut evidence file from the output of a label free experiment

Description

Experiment was performed by the Olsen lab and published on Nat. Commun. (citation below).

Usage

spectronaut_input

Format

a data.table with 23 columns and 2683 rows, the output of Spectronaut

Details

Bekker-Jensen, D.B., Bernhardt, O.M., Hogrebe, A. et al. Rapid and site-specific deep phosphoproteome profiling by data-independent acquisition without the need for spectral libraries. Nat Commun 11, 787 (2020). https://doi.org/10.1038/s41467-020-14609-1

The experiment was processed using Spectronaut by the computational proteomics team at Pfizer (Liang Xue and Pierre Jean).

The experiment did not contain a global profiling run, but we show an example of extracting the unmodified peptides and using them in place of the profiling run.

Examples

head(spectronaut_input)

Convert Spectronaut output into MSstatsPTM format

Description

Converters label-free Spectronaut data into MSstatsPTM format. Requires PSM output from Spectronaut and a custom made annotation file, mapping the run name to the condition and bioreplicate. Can optionally take a seperate PSM file for a global profiling run. If no global profiling run provided, the function can extract the unmodified peptides from the PTM PSM file and use them as a global profiling run (not recommended).

Usage

SpectronauttoMSstatsPTMFormat(
  input,
  annotation = NULL,
  fasta_path = NULL,
  protein_input = NULL,
  annotation_protein = NULL,
  use_unmod_peptides = FALSE,
  intensity = "PeakArea",
  mod_id = "\\[Phospho \\(STY\\)\\]",
  fasta_protein_name = "uniprot_iso",
  remove_other_mods = TRUE,
  filter_with_Qvalue = TRUE,
  qvalue_cutoff = 0.01,
  useUniquePeptide = TRUE,
  removeFewMeasurements = TRUE,
  removeProtein_with1Feature = FALSE,
  summaryforMultipleRows = max,
  use_log_file = TRUE,
  append = FALSE,
  verbose = TRUE,
  log_file_path = NULL
)

Arguments

input

name of Spectronaut PTM output, which is long-format. ProteinName, PeptideSequence, PrecursorCharge, FragmentIon, ProductCharge, IsotopeLabelType, Condition, BioReplicate, Run, Intensity, F.ExcludedFromQuantification are required. Rows with F.ExcludedFromQuantification=True will be removed.

annotation

name of 'annotation.txt' data which includes Condition, BioReplicate, Run. If annotation is already complete in Spectronaut, use annotation=NULL (default). It will use the annotation information from input.

fasta_path

string containing path to the corresponding fasta file for the modified peptide dataset.

protein_input

name of Spectronaut global protein output, which is as in the same format as input parameter.

annotation_protein

name of annotation file for global protein data, in the same format as above.

use_unmod_peptides

If protein_input is not provided, unmodified peptides can be extracted from input to be used in place of a global profiling run. Default is FALSE.

intensity

'PeakArea'(default) uses not normalized peak area. 'NormalizedPeakArea' uses peak area normalized by Spectronaut. Default is NULL

mod_id

Character that indicates the modification of interest. Default is ⁠\\(Phospho\\)⁠. Note ⁠\\⁠ must be included before special characters.

fasta_protein_name

Name of fasta column that matches with protein name in evidence file. Default is uniprot_iso.

remove_other_mods

Remove peptides which include modfications other than the one listed in mod_id. Default is TRUE. For example, in an experiment targeting Phosphorylation, setting this parameter to TRUE would remove peptides like (Acetyl (Protein N-term))AAAAPDSRVS(Phospho (STY))EEENLK. Set this parameter to FALSE to keep peptides with extraneous modifications.

filter_with_Qvalue

TRUE(default) will filter out the intensities that have greater than qvalue_cutoff in EG.Qvalue column. Those intensities will be replaced with zero and will be considered as censored missing values for imputation purpose.

qvalue_cutoff

Cutoff for EG.Qvalue. Default is 0.01.

useUniquePeptide

TRUE (default) removes peptides that are assigned for more than one proteins. We assume to use unique peptide for each protein.

removeFewMeasurements

TRUE (default) will remove the features that have 1 or 2 measurements across runs.

removeProtein_with1Feature

TRUE will remove the proteins which have only 1 feature, which is the combination of peptide, precursor charge, fragment and charge. FALSE is default.

summaryforMultipleRows

max(default) or sum - when there are multiple measurements for certain feature and certain run, use highest or sum of multiple intensities.

use_log_file

logical. If TRUE, information about data processing will be saved to a file.

append

logical. If TRUE, information about data processing will be added to an existing log file.

verbose

logical. If TRUE, information about data processing wil be printed to the console.

log_file_path

character. Path to a file to which information about data processing will be saved. If not provided, such a file will be created automatically. If 'append = TRUE', has to be a valid path to a file.

Value

a list of two data.tables named 'PTM' and 'PROTEIN' in the format required by MSstatsPTM.

Examples

head(spectronaut_input)
head(spectronaut_annotation)

msstats_input = SpectronauttoMSstatsPTMFormat(spectronaut_input, 
                  annotation=spectronaut_annotation, 
                  fasta_path=system.file("extdata", "spectronaut_fasta.fasta", package="MSstatsPTM"),
                  use_unmod_peptides=TRUE,
                  mod_id = "\\[Phospho \\(STY\\)\\]",
                  fasta_protein_name = "uniprot_iso"
                  )

head(msstats_input$PTM)
head(msstats_input$PROTEIN)

Example of output from dataSummarizationPTM function for non-TMT data

Description

It is made from raw.input. It is the output of dataSummarizationPTM function from MSstatsPTM. It should include a list with two names PTM and PROTEIN. Each of these list values is also a list with two names ProteinLevelData and FeatureLevelData, which correspond to two data.tables.The columns in these two data.tables are listed below. The variables are as follows:

  • FeatureLevelData :

    • PROTEIN : Protein ID with modification site mapped in. Ex. Protein_1002_S836

    • PEPTIDE : Full peptide with charge

    • TRANSITION: Charge

    • FEATURE : Combination of Protien, Peptide, and Transition Columns

    • LABEL :

    • GROUP : Condition (ex. Healthy, Cancer, Time0)

    • RUN : Unique ID for technical replicate of one TMT mixture.

    • SUBJECT : Unique ID for biological subject.

    • FRACTION : Unique Fraction ID

    • originalRUN : Run name

    • censored :

    • INTENSITY : Unique ID for TMT mixture.

    • ABUNDANCE : Unique ID for TMT mixture.

    • newABUNDANCE : Unique ID for TMT mixture.

    • predicted : Unique ID for TMT mixture.

  • ProteinLevelData :

    • RUN : MS run ID

    • Protein : Protein ID with modification site mapped in. Ex. Protein_1002_S836

    • LogIntensities: Protein-level summarized abundance

    • originalRUN : Labeling information (126, ... 131)

    • GROUP : Condition (ex. Healthy, Cancer, Time0)

    • SUBJECT : Unique ID for biological subject.

    • TotalGroupMeasurements : Unique ID for technical replicate of one TMT mixture.

    • NumMeasuredFeature : Unique ID for TMT mixture.

    • MissingPercentage : Unique ID for TMT mixture.

    • more50missing : Unique ID for TMT mixture.

    • NumImputedFeature : Unique ID for TMT mixture.

Usage

summary.data

Format

A list of two lists with four data.tables.

Examples

head(summary.data)

Example of output from dataSummarizationPTM_TMT function for TMT data

Description

It is made from raw.input.tmt. It is the output of dataSummarizationPTM_TMT function from MSstatsPTM. It should include a list with two names PTM and PROTEIN. Each of these list values is also a list with two names ProteinLevelData and FeatureLevelData, which correspond to two data.tables.The columns in these two data.tables are listed below. The variables are as follows:

  • FeatureLevelData :

    • ProteinName : MS run ID

    • PSM : Protein ID with modification site mapped in. Ex. Protein_1002_S836

    • censored: Protein-level summarized abundance

    • predicted : Labeling information (126, ... 131)

    • log2Intensity : Condition (ex. Healthy, Cancer, Time0)

    • Run : Unique ID for biological subject.

    • Channel : Unique ID for technical replicate of one TMT mixture.

    • BioReplicate : Unique ID for TMT mixture.

    • Condition : Unique ID for TMT mixture.

    • Mixture : Unique ID for TMT mixture.

    • TechRepMixture : Unique ID for TMT mixture.

    • PeptideSequence : Unique ID for TMT mixture.

    • Charge : Unique ID for TMT mixture.

  • ProteinLevelData :

    • Mixture : MS run ID

    • TechRepMixture : Protein ID with modification site mapped in. Ex. Protein_1002_S836

    • Run: Protein-level summarized abundance

    • Channel : Labeling information (126, ... 131)

    • Protein : Condition (ex. Healthy, Cancer, Time0)

    • Abundance : Unique ID for biological subject.

    • BioReplicate : Unique ID for technical replicate of one TMT mixture.

    • Condition : Unique ID for TMT mixture.

Usage

summary.data.tmt

Format

A list of two lists with four data.tables.

Examples

head(summary.data.tmt)

Read and tidy a FASTA file

Description

tidyFasta reads and tidys FASTA file. Use this function as the first step in identifying modification sites.

Usage

tidyFasta(path)

Arguments

path

A string of path to a FASTA file.

Value

A data.table with columns named header, sequence, uniprot_ac, uniprot_iso, entry_name.

Examples

tidyFasta(system.file("extdata", "O13297.fasta", package="MSstatsPTM"))