Figure 1.

A cartoon model of a focal adhesion complex depicting the role of vinculin and α-actinin. (a) The structural model of α-actinin shown here is constructed by Liu et al. (12). α-Actinin has three main structural domains: the CaM domain, the central rod domain with four spectrin repeats, (R1–R4), and two calponin homology domains known as CH1 and CH2. (b) The triple helical structure of spectrin repeats (A–C helices) form coiled-coil conformation. (c) The CaM domain contains four EF hand motifs (EF12 and EF34). (d) The primary role of α-actinin is to cross-link actin filaments, and vinculin is suggested to act as a reinforcing agent. Vinculin, α-actinin, and talin build a physical connection between the cytoskeleton and the extracellular matrix.