Tension-dependent Generation of Biochemical Signals on Actomyosin Fibers

Abstract

Actomyosin fibers in non-muscle cells generate contractile force to drive cell morphogenesis and migration. We find another role of these fibers as a platform for generating force-dependent biochemical signals. The MAP kinase ERK is activated on actomyosin fibers in response to tension developed in the fibers, which contributes to detecting anisotropy of cell deformation. The actin-binding, myosin-modulating protein calponin-3 is also phosphorylated on actomyosin fibers dependently on the fiber tension, which in turn increases myosin-based contractile force generation in the fibers. This positive feedback mechanism for tension development in actomyosin fibers enhances generation of force-dependent biochemical signals on the fibers.