Zyxin emerges as a key player in the mechanotransduction at cell adhesive structures

Abstract

Actin stress fiber (SF), focal adhesion (FA) and adherens junction (AJ) are known structures whose formation and development are mechanical force-dependent. At these structures, actin is actively polymerized, which in turn contributes the development of these structures. Recently, we reported that actin polymerization at FAs is facilitated by mechanical forces, which was critically dependent on the force-induced recruitment of the LIM protein zyxin to FAs. Zyxin enhances actin polymerization with the aid of Ena/VASP proteins. Both zyxin and Ena/VASP proteins are localized not only to FAs but also to AJs and SFs, facilitating actin polymerization at these structures. We discuss here the possibility that zyxin is a common mechanotransducer element regulating actin polymerization at FAs, AJs and SFs.

Keywords: Ena/VASP; actin polymerization; adherens junction; focal adhesion; mechanotransduction; stress fiber; zyxin.

Figure 1

Hypothetical diagrams showing zyxin as a common regulator of force-dependent actin polymerization at focal adhesions (FA), stress fibers (SF) and adherens junctions (AJ). (A) Side-view of cells adhering to ECM via FAs and to each other via AJs. FAs are connected each other by SFs, and AJs are linked to actomyosin cables. Actomyosin interaction and/or stretching the substratum generate tension in FAs, SFs and AJs. (B and C) Side-view of an FA and a SF (B) and top-view of an AJ (C). In response to mechanical forces, the conformations of hypothetical mechanosensor molecules (MS) at FAs, SFs and AJs are changed, rendering binding-sites for zyxin. The force-dependent recruitment of zyxin to FAs, SFs and AJs leads to the accumulation of Ena/VASP proteins, facilitating the actin polymerization at these structures.