KSEAapp Package Overview

This vignette will demonstrate potential usage for the available features within this package.

The fundamental calculations underlying this package is based on work published in Casado et al. (2013) Sci Signal. 6(268):rs6. Please refer to this paper for details on the formula.

Details on this R package and applications can be further found in Wiredja et al. (2017) Bioinformatics 33(21):3489-3491.

Please note: To maintain compliance with updated CRAN policies, KSEA App package v2.0 no longer offers KSEA.Complete(), as this function writes outputs directly to the user’s filespace.

1) Generate the K-S table using the KSEA.KS_table() function

This is the overview of all the required parameters for KSEA.KS_table()

• KSData: the Kinase-Substrate (K-S) dataset as described above
• PX: the experimental data file as described above
• NetworKIN: a binary input of TRUE or FALSE, indicating whether or not to include NetworKIN predictions; NetworKIN = TRUE means inclusion of NetworKIN predictions
• NetworKIN.cutoff: a numeric value between 1 and infinity setting the minimum NetworKIN score (can be left out if NetworKIN = FALSE)

Here is an example type-up for the R Console:

KSData.dataset <- KSEA.KS_table(KSData, PX, NetworKIN=TRUE, NetworKIN.cutoff=5)

This generates a complete table listing ALL the K-S relationships identified from the experimental dataset. This includes relationships for kinases that are not featured in the bar plot. For each kinase, every substrate identified from the dataset was used for the KSEA calculations (in other words, there was no filtering of the substrates). Kinase.Gene represents the gene name for each kinase. Substrate.Gene indicates the gene name for each substrate linked to that kinase. Substrate.Mod is the substrate’s specific amino acid residue that was modified. Source shows the database where the K-S annotation was derived from. log2FC is the log2(fold change) value of that particular substrate phosphosite from the experiment. If that same site was detected across multiple peptides that map to the same protein, the average log2FC is reported.

2) Generate the KSEA kinase scores using the KSEA.Scores() function

This is the overview of all the required parameters for KSEA.Scores()

• KSData: the Kinase-Substrate (K-S) dataset as described above
• PX: the experimental data file as described above
• NetworKIN: a binary input of TRUE or FALSE, indicating whether or not to include NetworKIN predictions; NetworKIN = TRUE means inclusion of NetworKIN predictions
• NetworKIN.cutoff: a numeric value between 1 and infinity setting the minimum NetworKIN score (can be left out if NetworKIN = FALSE)

Here is an example type-up for the R Console:

Scores <- KSEA.Scores(KSData, PX, NetworKIN=TRUE, NetworKIN.cutoff=5)

This is a complete table listing ALL the kinases, including those that are not featured in the bar plot, that have at least one identified substrate in the input dataset. Please refer to the original Casado et al. publication for detailed description of these columns and what they represent. Kinase.Gene indicates the gene name for each kinase. mS represents the mean log2(fold change) of all the kinase’s substrates. Enrichment is the background-adjusted value of the kinase’s mS. m is the total amount of detected substrates from the experimental dataset for each kinase. z.score is the normalized score for each kinase, weighted by the number of identified substrates. p.value represents the statistical assessment for the z.score. FDR is the p-value adjusted for multiple hypothesis testing using the Benjamini & Hochberg method.

3) For single-condition experiment, generate a summary bar plot using the KSEA.Barplot() function

This is the overview of all the required parameters for KSEA.Barplot()

• KSData: the Kinase-Substrate (K-S) dataset as described above
• PX: the experimental data file as described above
• NetworKIN: a binary input of TRUE or FALSE, indicating whether or not to include NetworKIN predictions; NetworKIN = TRUE means inclusion of NetworKIN predictions
• NetworKIN.cutoff: a numeric value between 1 and infinity setting the minimum NetworKIN score (can be left out if NetworKIN = FALSE)
• m.cutoff: a numeric value between 0 and infinity indicating the min. # of substrates a kinase must have to be included in the bar plot output
• p.cutoff: a numeric value between 0 and 1 indicating the p-value cutoff for indicating significant kinases in the bar plot

Here is an example type-up for the R Console:

KSEA.Barplot(KSData, PX, NetworKIN=TRUE, NetworKIN.cutoff=5, m.cutoff=5, p.cutoff=0.01)

This is the bar plot that summarizes the KSEA results. Note that not all kinases are included. The kinase substrate count cutoff, set by m.cutoff, decides which kinases to include in this plot. The p-value cutoff, set by p.cutoff, decides which kinases to color blue/red for visual annotation of kinases that reach statistical significance. Kinases with non-significant scores will be black.

4) For multi-condition experiments, alternatively generate a summary heatmap using the KSEA.Heatmap() function

Important notes:

• This function is designed for compiling results of studies that have 2+ treatment/case conditions; otherwise, the KSEA.Barplot() function should be used if there is just a single treatment group and a single control group.
• Before using KSEA.Heatmap(), you need to generate the outputs from KSEA.Scores() for each desired pairwise comparison in the study.
• The separate objects from KSEA.Scores() will need to be put into a list for input into KSEA.Heatmap().

This is the overview of all the required parameters for KSEA.Heatmap():

• score.list: the data frame outputs from the KSEA.Scores() function, compiled in a list format
• sample.labels: a character vector of all the sample names for heatmap annotation; the names must be in the same order as the data in score.list; please avoid long names, as they may get cropped in the final image
• stats: character string of either “p.value” or “FDR” indicating the data column to use for marking statistically significant scores
• m.cutoff: a numeric value between 0 and infinity indicating the min. # of substrates a kinase must have to be included in the heatmap
• p.cutoff: a numeric value between 0 and 1 indicating the p-value or FDR cutoff for indicating significant kinases in the heatmap
• sample.cluster: a binary input of TRUE or FALSE, indicating whether or not to perform hierarchical clustering of the sample columns

Here is an example type-up for the R Console:

KSEA.Heatmap(score.list=list(KSEA.Scores.1, KSEA.Scores.2, KSEA.Scores.3), 
             sample.labels=c("Tumor.A", "Tumor.B", "Tumor.C"), 
             stats="p.value", m.cutoff=3, p.cutoff=0.05, sample.cluster=TRUE)

This should result in a heatmap. Blue = negative kinase scores; White = zero-valued kinase scores; Red = positve kinase scores; Asterisks = scores that met the statistical cutoff, as indicated by the p.cutoff parameter.