Structural mechanism for bi-directional actin crosslinking by human T-plastin

Abstract

The actin cytoskeleton, a network of actin filaments, myosin motor proteins, and hundreds of associated partners, governs cell shape, powers motility, and facilitates generation and detection of cellular mechanical forces. To carry out these tasks, actin filaments must be incorporated into higher-order assemblies with diverse architectures, dictated by specialized actin-crosslinking proteins which bridge filaments to control their relative orientations and spacings. Mechanisms of actin crosslinkers are poorly defined at the protein structural level due to a lack of methods for visualizing them actively bridging filaments at high-resolution.