Myosin II Recruitment during Cytokinesis Independent of Centralspindlin-mediated Phosphorylation
Myosin II Recruitment during Cytokinesis Independent of Centralspindlin-mediated Phosphorylation
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DOI：
10.1074/jbc.m109.028316
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发表时间：
2009-10-02
影响因子：
4.8
通讯作者：
Egelhoff, Thomas T.
中科院分区：
文献类型：
--
作者：
Beach, Jordan R.;Egelhoff, Thomas T.
在细胞分裂过程中，肌球蛋白II被募集到收缩环的机制还不完全清楚。最近的工作集中在一个模型中，空间限制从头丝组装发生在细胞赤道通过本地化的肌球蛋白II调节轻链（RLC）磷酸化，刺激的RhoA激活centralspindlin复合物。在这里，我们表明，重组肌球蛋白IIA蛋白，组装组成，是无法结合RLC仍然显示出强大的本地化的哺乳动物细胞中的沟。此外，这种RLC缺陷的肌球蛋白II有效地驱动胞质分裂，表明centralspindlin为基础的RLC磷酸化是不必要的肌球蛋白II定位在开沟。肌球蛋白II截短分析进一步揭示了两个不同的肌球蛋白II尾部特性，有助于沟定位：一个中央尾域介导皮质沟结合异源结合伙伴和羧基末端区域介导与现有沟肌球蛋白IIA或IIB丝共组装。
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.