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Updated: Feb 15, 2026

Phosphoproteomic Strategy for Profiling Osmotic Stress Signaling in Arabidopsis
Published on: June 25, 2020
Phosphoproteomics-Based Profiling of Kinase Activities in Cancer Cells
Jakob Wirbel1,2, Pedro Cutillas3, Julio Saez-Rodriguez4,5
1Joint Research Center for Computational Biomedicine (JRC-COMBINE), Faculty of Medicine, RWTH Aachen University, MTZ Pauwelsstrasse 19, D-52074, Aachen, Germany.
Abstract:
Cellular signaling, predominantly mediated by phosphorylation through protein kinases, is found to be deregulated in most cancers. Accordingly, protein kinases have been subject to intense investigations in cancer research, to understand their role in oncogenesis and to discover new therapeutic targets. Despite great advances, an understanding of kinase dysfunction in cancer is far from complete.A powerful tool to investigate phosphorylation is mass-spectrometry (MS)-based phosphoproteomics, which enables the identification of thousands of phosphorylated peptides in a single experiment. Since every phosphorylation event results from the activity of a protein kinase, high-coverage phosphoproteomics data should indirectly contain comprehensive information about the activity of protein kinases.In this chapter, we discuss the use of computational methods to predict kinase activity scores from MS-based phosphoproteomics data. We start with a short explanation of the fundamental features of the phosphoproteomics data acquisition process from the perspective of the computational analysis. Next, we briefly review the existing databases with experimentally verified kinase-substrate relationships and present a set of bioinformatic tools to discover novel kinase targets. We then introduce different methods to infer kinase activities from phosphoproteomics data and these kinase-substrate relationships. We illustrate their application with a detailed protocol of one of the methods, KSEA (Kinase Substrate Enrichment Analysis). This method is implemented in Python within the framework of the open-source Kinase Activity Toolbox (kinact), which is freely available at http://github.com/saezlab/kinact/ .
Insights
This study explores using computational methods to predict protein kinase activity from mass-spectrometry phosphoproteomics data. These tools aid in understanding kinase dysfunction in cancer and identifying new therapeutic targets.
Area of Science:
- Oncology
- Biochemistry
- Bioinformatics
Background:
- Cellular signaling, particularly phosphorylation by protein kinases, is frequently deregulated in cancer, making kinases critical targets for research and therapy.
- Despite extensive investigation, a complete understanding of kinase dysfunction in oncogenesis remains elusive.
- Mass-spectrometry (MS)-based phosphoproteomics offers a powerful approach to study phosphorylation, identifying thousands of phosphopeptides and indirectly reflecting protein kinase activity.
Purpose of the Study:
- To discuss computational methods for predicting kinase activity scores from MS-based phosphoproteomics data.
- To review existing databases of kinase-substrate relationships and bioinformatic tools for novel kinase target discovery.
- To introduce and illustrate methods for inferring kinase activities, including a detailed protocol for Kinase Substrate Enrichment Analysis (KSEA).
Main Methods:
- Explanation of phosphoproteomics data acquisition from a computational analysis perspective.
- Review of databases for experimentally verified kinase-substrate relationships.
- Introduction of computational tools and methods, including KSEA, to infer kinase activity from phosphoproteomics data and kinase-substrate relationships.
Main Results:
- The chapter details computational approaches to derive kinase activity insights from phosphoproteomics data.
- It highlights the utility of KSEA, implemented in the open-source Kinase Activity Toolbox (kinact).
- The presented methods facilitate the discovery of novel kinase targets and understanding of kinase roles in cancer.
Conclusions:
- Computational analysis of phosphoproteomics data provides valuable insights into protein kinase activity in cancer.
- Tools like KSEA, integrated into the kinact toolbox, enable robust prediction of kinase activity scores.
- This approach aids in advancing cancer research by elucidating kinase dysfunction and identifying potential therapeutic strategies.
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