Molecular mechanism for orienting membrane and actin dynamics to nascent cell-cell contacts in epithelial cells.

J Biol Chem

Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305-5426, USA.

Published: November 2002

The small GTPase Rac1 has been implicated in regulation of cell migration and cell-cell adhesion in epithelial cells. Little is known, however, about the spatial and temporal coordination of Rac1 activity required to balance these competing processes. We fractionated endogenous Rac1-containing protein complexes from membranes of Madin-Darby canine kidney cells and identified three major complexes comprising a Rac1.PAK (p21-activated kinase) complex, and 11 S and 16 S Rac1 complexes. Significantly, Rac1 shifts from the 11 S to a 16 S particle during initiation of cell-cell adhesion. This shift may reflect a diffusion trapping mechanism by which these Rac1 complexes are localized to cadherin-mediated cell-cell contacts through an interaction with annexin II.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368610PMC
http://dx.doi.org/10.1074/jbc.M207747200DOI Listing

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