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Updated: Jun 29, 2026
12:26
Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
Published on: May 3, 2018
Identification of CDK2 substrates in human cell lysates
Yong Chi1, Markus Welcker, Asli A Hizli
1Divisions of Clinical Research and Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, WA 98109, USA.
Genome Biology
|October 14, 2008
Summary
Researchers identified 180 potential cyclin A-CDK2 substrates using engineered kinases and mass spectrometry. This advance helps map the complex cell cycle regulation networks controlled by cyclin-dependent kinases (CDKs).
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Protein phosphorylation is crucial for biological processes, but the vast number of kinases and substrates creates a complex phosphoproteome.
- Cyclin-dependent kinases (CDKs) regulate cell cycle progression and are implicated in tumorigenesis.
- Identifying mammalian CDK substrates is essential for understanding CDK function and their regulatory networks.
Purpose of the Study:
- To develop and apply a method for identifying novel cyclin A-CDK2 substrates in complex cell lysates.
- To expand the known substrate network of cyclin A-CDK2.
Main Methods:
- Utilized a kinase engineering strategy combined with chemical enrichment.
- Employed mass spectrometry for high-throughput identification of potential substrates and phosphorylation sites.
- Validated identified candidates through direct phosphorylation assays and in vivo studies.
Main Results:
- Identified 180 potential cyclin A-CDK2 substrates and over 200 phosphorylation sites.
- Found that identified substrates are involved in cell division and other fundamental cellular processes.
- Validated several candidates as direct substrates, including ribosomal protein RL12, with site-specific in vivo phosphorylation.
Conclusions:
- Developed an efficient method using engineered kinases and thiophosphate enrichment to identify CDK2 substrates.
- The findings suggest CDKs regulate cell division through extensive substrate networks.
- The described methods are versatile and adaptable for discovering substrates of other protein kinases.
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