Long-range self-organization of cytoskeletal myosin II filament stacks

Nature Cell Biology 19, 133 (2017).
doi:10.1038/ncb3466

Authors: Shiqiong Hu, Kinjal Dasbiswas, Zhenhuan Guo, Yee-Han Tee, Visalatchi Thiagarajan, Pascal Hersen, Teng-Leong Chew, Samuel A. Safran, Ronen Zaidel-Bar & Alexander D. Bershadsky
Although myosin II filaments are known to exist in non-muscle cells, their dynamics and organization are incompletely understood. Here, we combined structured illumination microscopy with pharmacological and genetic perturbations, to study the process of actomyosin cytoskeleton self-organization into arcs and stress fibres. A striking feature of the myosin II filament organization was their ‘registered’ alignment into stacks, spanning up to several micrometres in the direction orthogonal to the parallel actin bundles. While turnover of individual myosin II filaments was fast (characteristic half-life time 60 s) and independent of actin filament turnover, the process of stack formation lasted a longer time (in the range of several minutes) and required myosin II contractility, as well as actin filament assembly/disassembly and crosslinking (dependent on formin Fmnl3, cofilin1 and α-actinin-4). Furthermore, myosin filament stack formation involved long-range movements of individual myosin filaments towards each other suggesting the existence of attractive forces between myosin II filaments. These forces, possibly transmitted via mechanical deformations of the intervening actin filament network, may in turn ...

Source: Nature Cell Biology - January 22, 2017 Category: Cytology Authors: Shiqiong Hu Kinjal Dasbiswas Zhenhuan Guo Yee-Han Tee Visalatchi Thiagarajan Pascal Hersen Teng-Leong Chew Samuel A. Safran Ronen Zaidel-Bar Alexander D. Bershadsky Tags: Letter Source Type: research