Cell Adhesion

Cleaving the Lynch Pin

Science's STKE  05 Oct 2004:
Vol. 2004, Issue 253, pp. tw354
DOI: 10.1126/stke.2532004tw354

Franco et al. examined the role of talin proteolysis by calpain, a calcium-dependent protease, in controlling adhesion complex stability. The dynamic formation and disassembly of these complexes is essential for cell motility. In cultured cells exposed to siRNA to decrease calpain 2 abundance, adhesion complexes were more stable and talin cleavage was inhibited. The authors analyzed adhesion complex stability in talin-deficient cells expressing a green fluorescent protein (GFP)-tagged form of talin either with or without a mutation that prevented calpain cleavage. In cells expressing the cleavage-deficient form of talin, adhesion complexes were more stable, exhibiting a decreased rate of disassembly. In addition, the adhesion complexes that contained the noncleavable form of talin were larger and elongated compared with those complexes containing wild-type talin. The authors speculate that because the talin cleavage products still bound some of their complex partners, for example, focal adhesion-targeted type I phosphatidylinositol phosphate kinase (PIPKI╬│661), redistribution of the talin cleavage products may also promote redistribution of other adhesion complex proteins, thereby facilitating adhesion complex disassembly.

S. J. Franco, M. A. Rodgers, B. J. Perrin, J. Han, D. A. Bennin, D. R. Critchley, A. Huttenlocher, Calpain-mediated proteolysis of talin regulates adhesion dynamics. Nat. Cell Biol. 6, 977-983 (2004). [Online Journal]