Determinants of myosin II cortical localization during cytokinesis.
Curr Biol
; 20(12): 1080-5, 2010 Jun 22.
Article
em En
| MEDLINE
| ID: mdl-20541410
ABSTRACT
Myosin II is an essential component of the contractile ring that divides the cell during cytokinesis. Previous work showed that regulatory light chain (RLC) phosphorylation is required for localization of myosin at the cellular equator. However, the molecular mechanisms that concentrate myosin at the site of furrow formation remain unclear. By analyzing the spatiotemporal dynamics of mutant myosin subunits in Drosophila S2 cells, we show that myosin accumulates at the equator through stabilization of interactions between the cortex and myosin filaments and that the motor domain is dispensable for localization. Filament stabilization is tightly controlled by RLC phosphorylation. However, we show that regulatory mechanisms other than RLC phosphorylation contribute to myosin accumulation at three different stages (1) turnover of thick filaments throughout the cell cycle, (2) myosin heavy chain-based control of myosin assembly at the metaphase-anaphase transition, and (3) redistribution and/or activation of myosin binding sites at the equator during anaphase. Surprisingly, the third event can occur to a degree in a Rho-independent fashion, gathering preassembled filaments to the equatorial zone via cortical flow. We conclude that multiple regulatory pathways cooperate to control myosin localization during mitosis and cytokinesis to ensure that this essential biological process is as robust as possible.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ciclo Celular
/
Miosina Tipo II
Idioma:
En
Revista:
Curr Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos