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Rnd3 interacts with TAO kinases and contributes to mitotic cell rounding and spindle positioning.
Ritu Garg1,2, Chuay-Yeng Koo1, Elvira Infante2
1King's College London, School of Cancer and Pharmaceutical Sciences, New Hunt's House, Guy's Campus, London SE1 1UL, UK.
Journal of Cell Science
|February 12, 2020
Summary
Thousand-and-one amino acid kinases (TAOKs) bind and phosphorylate Rnd3, a protein involved in cell shape. This interaction regulates Rnd3
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Rnd3 is an atypical Rho family protein that regulates actin stress fibers and cell rounding.
- Rnd3 phosphorylation leads to 14-3-3 binding and cytosolic relocation.
Purpose of the Study:
- To investigate the interaction between Rnd3 and thousand-and-one amino acid kinases (TAOKs).
- To elucidate the role of TAOK-mediated Rnd3 phosphorylation in mitosis.
Main Methods:
- In vitro and cellular binding assays to detect Rnd3-TAOK interactions.
- Phosphorylation site mapping of Rnd3 by TAOK1 and TAOK2.
- RNA interference (RNAi) to deplete Rnd3 and observe mitotic defects.
Main Results:
- Rnd3 directly binds to TAOK1 and TAOK2.
- TAOK1 and TAOK2 phosphorylate Rnd3 at specific serine residues, inducing its translocation to the cytosol.
- Rnd3 depletion impairs mitotic cell rounding, spindle centralization, and cytokinesis.
Conclusions:
- TAOKs bind, phosphorylate, and relocate Rnd3, contributing to mitotic progression.
- Rnd3 plays a role in regulating cell shape, spindle positioning, and cell division.
- Rnd3 acts downstream of TAOKs in cytoskeletal regulation during mitosis.
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