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Pseudopod growth and evolution during cell movement is controlled through SCAR/WAVE dephosphorylation
Seiji Ura1, Alice Y Pollitt, Douwe M Veltman
1Beatson Institute for Cancer Research, Bearsden, Glasgow, UK.
Current Biology : CB
|March 6, 2012
Summary
Dephosphorylation of SCAR/WAVE activates pseudopod growth in crawling cells. This process regulates pseudopod dynamics by controlling SCAR/WAVE complex activity and stability.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- SCAR/WAVE is a key regulator of pseudopod extension in motile cells.
- This protein functions as a stable pentameric complex with poorly understood regulatory mechanisms.
- Phosphorylation of SCAR/WAVE occurs at multiple sites, but its functional impact remains unclear.
Purpose of the Study:
- To investigate the role of SCAR/WAVE dephosphorylation in regulating pseudopod dynamics.
- To elucidate how phosphorylation affects SCAR/WAVE activity and its role in cell motility.
Main Methods:
- Analysis of SCAR/WAVE phosphorylation sites in Dictyostelium.
- Creation and functional assessment of SCAR/WAVE phosphorylation site mutants.
- Investigation of SCAR/WAVE complex interactions and stability.
Main Results:
- Dictyostelium SCAR/WAVE is basally phosphorylated at four C-terminal serine residues.
- Mutants lacking phosphorylation sites are hyperactive, while phosphomimetic mutants are hypoactive.
- Phosphorylation enhances autoinhibition of the SCAR/WAVE complex, while dephosphorylation promotes activation.
Conclusions:
- Regulated dephosphorylation of SCAR/WAVE is crucial for pseudopod growth activation.
- Dephosphorylation weakens SCAR/WAVE autoinhibition, facilitating activation by Rac and lipids.
- Specific dephosphorylation in pseudopods supports positive feedback loops driving cell motility.
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