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Sharpin suppresses β1-integrin activation by complexing with the β1 tail and kindlin-1
Juan Gao1, Yun Bao1, Shushu Ge1
1Collaborative Research Program for Cell Adhesion Molecules, Shanghai University School of Life Sciences, Shanghai, China.
Cell Communication and Signaling : CCS
|August 21, 2019
Summary
Sharpin inhibits β1-integrin activation by binding to its cytoplasmic tails and blocking talin binding. Kindlin-1 enhances this interaction, suggesting a complex mechanism for regulating integrin function.
Area of Science:
- Cell biology
- Molecular biology
- Biochemistry
Background:
- Sharpin is an endogenous inhibitor of β1-integrin activation.
- It binds to cytoplasmic tails (CTs) of integrin β1-associated α subunits.
Purpose of the Study:
- To evaluate the function and molecular mechanism of the sharpin-kindlin-1 complex in regulating β1-integrin activation.
Main Methods:
- Biochemical approaches
- Cellular analyses
Main Results:
- Sharpin inhibits β1-integrin activation but not αIIbβ3 activation.
- Sharpin directly interacts with the β1 CT, inhibiting talin binding.
- Kindlin-1 enhances sharpin-β1 CT interaction and suppresses talin-mediated activation.
Conclusions:
- Sharpin, kindlin-1, and the integrin β1 CT form a complex.
- This complex restricts talin binding, inhibiting β1-integrin activation.
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