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Podosome formation promotes plasma membrane invagination and integrin-β3 endocytosis on a viscous RGD-membrane
Fakun Cao1, Yuhuan Zhou1, Xiaoting Liu1
1School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China.
Communications Biology
|March 15, 2020
Summary
The study reveals how integrin-β3 receptors are endocytosed at podosomes. F-actin polymerization drives membrane invagination, recruiting BIN1 and DNM2 to facilitate this crucial cell adhesion process.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Integrin receptors are key regulators of cell adhesion and cytoskeletal dynamics.
- The precise mechanism of integrin-β3 endocytosis at podosomes is not fully understood.
Purpose of the Study:
- To elucidate the endocytic pathway of integrin-β3 at podosome structures.
- To investigate the roles of F-actin, BIN1, and DNM2 in integrin-β3 internalization.
Main Methods:
- Utilized a viscous RGD-membrane model system.
- Employed podosome formation inhibition and gene knockdown strategies (Dab2, clathrin, BIN1, DNM2).
- Observed integrin-β3 and RGD ligand endocytosis and localization within the endosomal compartment.
Main Results:
- Podosome formation facilitates Dab2/clathrin-mediated endocytosis of integrin-β3 and RGD ligand.
- F-actin assembly at the podosome core induces plasma membrane invaginations.
- BIN1 associates with invaginated membranes, recruiting DNM2 to promote endocytosis.
Conclusions:
- Plasma membrane invagination driven by F-actin polymerization is essential for integrin-β3 endocytosis at podosomes.
- BIN1-dependent recruitment of DNM2 facilitates integrin-β3 internalization via a clathrin-independent mechanism at later stages.
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