Actin network architecture can determine myosin motor activity.
The organization of actin filaments into higher-ordered structures governs eukaryotic cell shape and movement. Global actin network size and architecture are maintained in a dynamic steady state through regulated assembly and disassembly. Here, we used experimentally defined actin structures in vitro to investigate how the activity of myosin motors depends on network architecture. Direct visualization of filaments revealed myosin-induced actin network deformation. During this reorganization, myosins selectively contracted and disassembled antiparallel actin structures, while parallel actin bundles remained unaffected. The local distribution of nucleation sites and the resulting orientation of actin filaments appeared to regulate the scalability of the contraction process. This "orientation selection" mechanism for selective contraction and disassembly suggests how the dynamics of the cellular actin cytoskeleton can be spatially controlled by actomyosin contractility.
Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA)-Institut National de la Recherche Agronomique (INRA), Grenoble, France.
Anne-Cécile
AC
Reymann
Rajaa
R
Boujemaa-Paterski
Jean-Louis
JL
Martiel
Christophe
C
Guérin
Wenxiang
W
Cao
Harvey F
HF
Chin
Enrique M
EM
De La Cruz
Manuel
M
Théry
Laurent
L
Blanchoin
D008841:Actin Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure*; D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D000205:Actomyosin / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D018995:Myosin Heavy Chains / Q000737:chemistry / Q000378:metabolism*; D024462:Myosin Type II / Q000737:chemistry / Q000378:metabolism*; D011817:Rabbits; D013552:Swine
D000199:Actins; C089785:myosin VI; D000205:Actomyosin; D024462:Myosin Type II; D018995:Myosin Heavy Chains