Saint Robert, Somers W Gregory
Centre for the Molecular Genetics of Development, Research School of Biological Sciences, Australian National University, Canberra ACT 0200, Australia.
J Cell Sci. 2003 Nov 1;116(Pt 21):4277-81. doi: 10.1242/jcs.00816.
Despite a century of research into the nature of animal cell division, a molecular explanation for the positioning of the actomyosin contractile ring has remained elusive. The discovery of a novel interaction between regulators of Rho family small GTPases has revealed a link between the mitotic microtubules and the contractile ring during the later stages of mitosis. The properties of the interacting Rho regulators suggest a molecular model for the positioning and initiation of contractile ring furrowing in animal cells. In this 'double ring' model, centralspindlin complexes, localized by the action of their kinesin-like protein component, position and activate a cortical equatorial ring of Rho GTPase exchange factors. The resulting ring of activated Rho would then trigger a cascade of events leading to formation and constriction of the contractile ring.
尽管对动物细胞分裂的本质进行了一个世纪的研究，但对于肌动球蛋白收缩环定位的分子解释仍然难以捉摸。Rho家族小GTP酶调节因子之间一种新相互作用的发现，揭示了有丝分裂后期有丝分裂微管与收缩环之间的联系。相互作用的Rho调节因子的特性提示了动物细胞中收缩环沟的定位和起始的分子模型。在这个“双环”模型中，中心纺锤体复合物通过其类驱动蛋白成分的作用进行定位，从而定位并激活Rho GTP酶交换因子的皮质赤道环。由此产生的活化Rho环随后会引发一系列事件，导致收缩环的形成和收缩。
