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Protein Phosphatase 2A (PP2A) Regulates EG5 to Control Mitotic Progression
Yang Liu1, Zhong Zhang1, Hui Liang1
1Department of Pathology, Institute of Systems Biomedicine, School of Basic Medical Sciences, Beijing Key Laboratory of Systems Biology, Peking University Health Science Center, 38 Xueyuan Road, Beijing 100191, P.R. China.
Scientific Reports
|May 11, 2017
Summary
Protein phosphatase 2A (PP2A) dephosphorylates Eg5 (KIF11) at Thr926, enabling mitotic exit. PP2A knockdown delays mitotic exit by maintaining Eg5 phosphorylation, highlighting PP2A
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Eg5 (KIF11) is crucial for bipolar spindle formation during mitosis.
- CDK1-mediated phosphorylation of Eg5 at Thr926 promotes its spindle localization.
- Regulation of Eg5 detachment from the spindle during mitotic exit remains unclear.
Purpose of the Study:
- To investigate the role of phosphatases in Eg5 regulation during mitotic exit.
- To identify novel regulators of Eg5 dephosphorylation and mitotic progression.
Main Methods:
- Biochemical assays to identify Eg5 phosphatase activity.
- Cellular experiments involving PP2A knockdown and Eg5/T926D transfection.
- Immunofluorescence and Western blotting to assess protein phosphorylation and localization.
Main Results:
- Eg5 (KIF11) is identified as a novel substrate of Protein Phosphatase 2A (PP2A).
- The PP2A/B55α complex directly dephosphorylates Eg5 at Thr926, facilitating mitotic exit.
- PP2A knockdown results in elevated phospho-Eg5, delaying mitotic exit and mimicking Eg5/T926D effects.
Conclusions:
- PP2A-mediated dephosphorylation of Eg5 is essential for timely mitotic exit.
- Dysregulation of PP2A leads to abnormal Eg5 activity and delayed cell cycle progression.
- PP2A acts as a key regulator controlling Eg5 function during the final stages of mitosis.
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