Myosin II recruitment during cytokinesis independent of centralspindlin-mediated phosphorylation.
During cell division, the mechanisms by which myosin II is recruited to the contractile ring are not fully understood. Much recent work has focused on a model in which spatially restricted de novo filament assembly occurs at the cell equator via localized myosin II regulatory light chain (RLC) phosphorylation, stimulated by the RhoA-activating centralspindlin complex. Here, we show that a recombinant myosin IIA protein that assembles constitutively and is incapable of binding RLC still displays strong localization to the furrow in mammalian cells. Furthermore, this RLC-deficient myosin II efficiently drives cytokinesis, demonstrating that centralspindlin-based RLC phosphorylation is not necessary for myosin II localization during furrowing. Myosin II truncation analysis further reveals two distinct myosin II tail properties that contribute to furrow localization: a central tail domain mediating cortical furrow binding to heterologous binding partners and a carboxyl-terminal region mediating co-assembly with existing furrow myosin IIA or IIB filaments.
Beach
Jordan R
JR
Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
Egelhoff
Thomas T
TT
D000818:Animals; D019556:COS Cells; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002522:Chlorocebus aethiops; D048749:Cytokinesis; D017353:Gene Deletion; D006681:HLA-D Antigens / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D018994:Myosin Light Chains / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D024462:Myosin Type II / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D018797:Cell Cycle Proteins; D006681:HLA-D Antigens; D008869:Microtubule-Associated Proteins; D018994:Myosin Light Chains; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; C104434:spindlin; D024462:Myosin Type II