RIAM and Vinculin Binding to Talin Are Mutually Exclusive and Regulate Adhesion Assembly and Turnover

• DOI: 10.1074/jbc.m112.438119
• Publication Date: 2013-02-07T06:45:12Z
• Authors: Benjamin T. Goult; Thomas Zacharchenko; Neil Bate; Ricky Tsang; Fiona Hey; Alexandre R. Gingras; Paul R. Elliott; Gordon C.K. Roberts; Christoph Ballestrem; David R. Critchley; Igor L. Barsukov
• Keywords: Vinculin

Talin activates integrins, couples them to F-actin, and recruits vinculin focal adhesions (FAs). Here, we report the structural characterization of talin rod: 13 helical bundles (R1–R13) organized into a compact cluster four-helix (R2–R4) within linear chain five-helix bundles. Nine contain vinculin-binding sites (VBS); R2R3 are atypical, with each containing two VBS. also binds synergistically RIAM, Rap1 effector involved in integrin activation. Biochemical data show that RIAM binding is mutually exclusive. Moreover, requires domain unfolding, whereas folded double domain. In cells, enriched nascent at leading edge FAs. We propose model which initially membranes where it integrins. As engages force exerted on disrupts exposes VBS, recruit stabilize complex.