?V-class integrins exert dual roles on ?5?1 integrins to strengthen adhesion to fibronectin.

ABSTRACT: Upon binding to the extracellular matrix protein, fibronectin, ?V-class and ?5?1 integrins trigger the recruitment of large protein assemblies and strengthen cell adhesion. Both integrin classes have been functionally specified, however their specific roles in immediate phases of cell attachment remain uncharacterized. Here, we quantify the adhesion of ?V-class and/or ?5?1 integrins expressing fibroblasts initiating attachment to fibronectin (?120?s) by single-cell force spectroscopy. Our data reveals that ?V-class integrins outcompete ?5?1 integrins. Once engaged, ?V-class integrins signal to ?5?1 integrins to establish additional adhesion sites to fibronectin, away from those formed by ?V-class integrins. This crosstalk, which strengthens cell adhesion, induces ?5?1 integrin clustering by RhoA/ROCK/myosin-II and Arp2/3-mediated signalling, whereas overall cell adhesion depends on formins. The dual role of both fibronectin-binding integrin classes commencing with an initial competition followed by a cooperative crosstalk appears to be a basic cellular mechanism in assembling focal adhesions to the extracellular matrix.

SUBMITTER: Bharadwaj M 

PROVIDER: S-EPMC5290147 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature