Differential Effect of Actomyosin Relaxation on the Dynamic Properties of Focal Adhesion Proteins

作者：Lavelin Irena; Wolfenson Haguy; Patla Israel; Henis Yoav I; Medalia Ohad; Volberg Tova; Livne Ariel; Kam Zvi; Geiger Benjamin^*

来源：PLos One, 2013, 8(9): e73549.

DOI：10.1371/journal.pone.0073549

Treatment of cultured cells with inhibitors of actomyosin contractility induces rapid deterioration of stress fibers, and disassembly of the associated focal adhesions (FAs). In this study, we show that treatment with the Rho kinase inhibitor Y-27632, which blocks actomyosin contractility, induces disarray in the FA-associated actin bundles, followed by the differential dissociation of eight FA components from the adhesion sites. Live-cell microscopy indicated that the drug triggers rapid dissociation of VASP and zyxin from FAs (tau values of 7-8 min), followed by talin, paxillin and ILK (tau similar to 16 min), and then by FAK, vinculin and kindlin-2 (tau = 25-28 min). Examination of the molecular kinetics of the various FA constituents, using Fluorescence Recovery After Photobleaching (FRAP), in the absence of or following short-term treatment with the drug, revealed major changes in the k(on) and k(off) values of the different proteins tested, which are in close agreement with their differential dissociation rates from the adhesion sites. These findings indicate that mechanical, actomyosin-generated forces differentially regulate the molecular kinetics of individual FA-associated molecules, and thereby modulate FA composition and stability.

• 出版日期2013-9-9