Related Experiment Video
Updated: Jul 17, 2025

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
Published on: May 3, 2018
Dynamic Phosphorylation of G9a Regulates its Repressive Activity on Chromatin Accessibility and Mitotic Progression
Qizhi Geng1, Yue-Yu Kong1, Weizhe Li1
1Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Hubei Clinical Research Center of Emergency and Resuscitation, Emergency Center of Zhongnan Hospital of Wuhan University, Frontier Science Center for Immunology and Metabolism, RNA Institute, Wuhan University, Wuhan, 430072, China.
Abstract:
Phosphorylation of Ser10 of histone H3 (H3S10p), together with the adjacent methylation of Lys9 (H3K9me), has been proposed to function as a 'phospho-methyl switch' to regulate mitotic chromatin architecture. Despite of immense understanding of the roles of H3S10 phosphorylation, how H3K9me2 are dynamically regulated during mitosis is poorly understood. Here, it is identified that Plk1 kinase phosphorylates the H3K9me1/2 methyltransferase G9a/EHMT2 at Thr1045 (pT1045) during early mitosis, which attenuates its catalytic activity toward H3K9me2. Cells bearing Thr1045 phosphomimic mutant of G9a (T1045E) show decreased H3K9me2 levels, increased chromatin accessibility, and delayed mitotic progression. By contrast, dephosphorylation of pT1045 during late mitosis by the protein phosphatase PPP2CB reactivates G9a activity and upregulates H3K9me2 levels, correlated with decreased levels of H3S10p. Therefore, the results provide a mechanistic explanation of the essential of a 'phospho-methyl switch' and highlight the importance of Plk1 and PPP2CB-mediated dynamic regulation of G9a activity in chromatin organization and mitotic progression.
More Related Videos
09:14Examination of Proteins Bound to Nascent DNA in Mammalian Cells Using BrdU-ChIP-Slot-Western Technique
Published on: January 14, 2016
08:33Combining Mitotic Cell Synchronization and High Resolution Confocal Microscopy to Study the Role of Multifunctional Cell Cycle Proteins During Mitosis
Published on: December 5, 2017
Related Concept Videos
Anaphase Promoting Complex
Separation of Sister Chromatids
At the onset of anaphase, separase, a proteolytic enzyme, is...
Positive Regulator Molecules
Inhibition of Cdk Activity
Histone Modification
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone...
M-Cdk Drives Transition Into Mitosis
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...