J Cancer 2020; 11(2):345-352. doi:10.7150/jca.32853 This issue

Research Paper

Integrin-mediated Signaling via Paxillin-GIT1-PIX Promotes Localized Rac Activation at the Leading Edge and Cell Migration

Youjun Li1, Xinzhou Wu1, Zhiqiang Liu1, Kanghui Lu1, Rushi Liu2✉, Xiangrong Guo1✉

1. Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hunan Normal University, Changsha 410081, China
2. Laboratory of Medical Molecular and Immunological Diagnostics, College of Medicine, Hunan Normal University, Changsha 410013, China

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Citation:
Li Y, Wu X, Liu Z, Lu K, Liu R, Guo X. Integrin-mediated Signaling via Paxillin-GIT1-PIX Promotes Localized Rac Activation at the Leading Edge and Cell Migration. J Cancer 2020; 11(2):345-352. doi:10.7150/jca.32853. Available from https://www.jcancer.org/v11p0345.htm

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Abstract

Rac activation is precisely regulated temporally and spatially by intracellular signaling pathways in migrating cells to guarantee the formation of specific cell protrusions-lamellipodia at the leading edge. Integrins-mediated adhesions also control the signaling pathway for localized Rac activation in the cells, but very few studies have been addressed in this field. In the study, we aim to focus on how integrin-mediated signaling affects localized Rac activation by reducing the paxillin expression with shRNA targeting paxillin. The results revealed that reduction of the paxillin expression in the cells inhibited the formation of focal adhesions and Rac activation. By using Rac FRET biosensor, Rac activation was localized at the leading edge of the cell, within the lamellipodium. A ternary complex of paxillin-GIT1-PIX could establish the signaling pathway in front of the cells. Thus, we described a mechanism of integrin-mediated signaling for localized Rac activation that upon ligand binding, activated integrin via the signaling pathway paxillin-GIT1-PIX promotes localized Rac activation at the leading edge and cell migration.

Keywords: integrin, localization Rac activation, leading edge, paxillin, signaling pathway