Curvature-induced expulsion of actomyosin bundles during cytokinetic ring contraction

TY - JOUR

T1 - Curvature-induced expulsion of actomyosin bundles during cytokinetic ring contraction

AU - Huang, Junqi

AU - Chew, Ting Gang

AU - Gu, Ying

AU - Palani, Saravanan

AU - Kamnev, Anton

AU - Martin, Douglas S.

AU - Carter, Nicholas J.

AU - Cross, Robert Anthony

AU - Oliferenko, Snezhana

AU - Balasubramanian, Mohan K.

PY - 2016/10/13

Y1 - 2016/10/13

N2 - Many eukaryotes assemble a ring-shaped actomyosin network that contracts to drive cytokinesis. Unlike actomyosin in sarcomeres, which cycles through contraction and relaxation, the cytokinetic ring disassembles during contraction through an unknown mechanism. Here we find in Schizosaccharomyces japonicus and Schizosaccharomyces pombe that, during actomyosin ring contraction, actin filaments associated with actomyosin rings are expelled as micron-scale bundles containing multiple actomyosin ring proteins. Using functional isolated actomyosin rings we show that expulsion of actin bundles does not require continuous presence of cytoplasm. Strikingly, mechanical compression of actomyosin rings results in expulsion of bundles predominantly at regions of high curvature. Our work unprecedentedly reveals that the increased curvature of the ring itself promotes its disassembly. It is likely that such a curvature-induced mechanism may operate in disassembly of other contractile networks.

AB - Many eukaryotes assemble a ring-shaped actomyosin network that contracts to drive cytokinesis. Unlike actomyosin in sarcomeres, which cycles through contraction and relaxation, the cytokinetic ring disassembles during contraction through an unknown mechanism. Here we find in Schizosaccharomyces japonicus and Schizosaccharomyces pombe that, during actomyosin ring contraction, actin filaments associated with actomyosin rings are expelled as micron-scale bundles containing multiple actomyosin ring proteins. Using functional isolated actomyosin rings we show that expulsion of actin bundles does not require continuous presence of cytoplasm. Strikingly, mechanical compression of actomyosin rings results in expulsion of bundles predominantly at regions of high curvature. Our work unprecedentedly reveals that the increased curvature of the ring itself promotes its disassembly. It is likely that such a curvature-induced mechanism may operate in disassembly of other contractile networks.

UR - http://www.scopus.com/inward/record.url?scp=84992666002&partnerID=8YFLogxK

U2 - 10.7554/eLife.21383

DO - 10.7554/eLife.21383

M3 - Article

AN - SCOPUS:84992666002

SN - 2050-084X

VL - 5

JO - eLife

JF - eLife

IS - October2016

M1 - e21383

ER -