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Updated: Jun 4, 2026
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Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
Published on: May 3, 2018
Filamin A stimulates cdc25C function and promotes entry into mitosis.
Elphine Telles1, Mansa Gurjar, Ketaki Ganti
1KS215 Advanced Centre for Treatment Research and Education in Cancer, Tata Memorial Centre Kharghar Node, Navi, Mumbai, India.
Cell Cycle (Georgetown, Tex.)
|February 18, 2011
Summary
Filamin A binds to the mitotic form of cdc25C, forming a complex that promotes mitotic progression. This actin-binding protein acts as a scaffold, facilitating cdc25C activation for cell division.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- The dual specificity phosphatase cdc25C is crucial for mitotic progression.
- Mechanisms of cdc25C activation before mitosis in human cells are not fully understood.
Purpose of the Study:
- To investigate the role of Filamin A in the regulation and activation of cdc25C during mitosis.
- To elucidate how Filamin A influences the assembly of the cyclin B1-cdk1-cdc25C complex.
Main Methods:
- In vivo complex formation assays between Filamin A and cdc25C.
- Co-expression and knockdown experiments to assess the impact of Filamin A on cdc25C activity.
- Analysis of Filamin A fragments to identify domains critical for cdc25C interaction and activation.
Main Results:
- Filamin A forms a complex with cdc25C in vivo, preferentially binding to its mitotic form.
- Filamin A co-expression enhances cdc25C-induced mitotic progression (PCC), while Filamin A knockdown reduces it.
- A specific Filamin A fragment, capable of binding cdc25C and cyclin B1 and possessing a dimerization domain, is required to stimulate cdc25C's ability to induce PCC.
Conclusions:
- Filamin A acts as a scaffold, facilitating the assembly of the cyclin B1-cdk1-cdc25C complex.
- This scaffolding function of Filamin A is essential for cdc25C activation and subsequent mitotic progression.
- Filamin A is a key regulator of mitotic entry through its interaction with the cdc25C phosphatase.
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