Generation of contractile actomyosin bundles depends on mechanosensitive actin filament assembly and disassembly.

ABSTRACT: Adhesion and morphogenesis of many non-muscle cells are guided by contractile actomyosin bundles called ventral stress fibers. While it is well established that stress fibers are mechanosensitive structures, physical mechanisms by which they assemble, align, and mature have remained elusive. Here we show that arcs, which serve as precursors for ventral stress fibers, undergo lateral fusion during their centripetal flow to form thick actomyosin bundles that apply tension to focal adhesions at their ends. Importantly, this myosin II-derived force inhibits vectorial actin polymerization at focal adhesions through AMPK-mediated phosphorylation of VASP, and thereby halts stress fiber elongation and ensures their proper contractility. Stress fiber maturation additionally requires ADF/cofilin-med

SUBMITTER: Tojkander S 

PROVIDER: S-EPMC4714978 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature