Rho and Anillin-dependent Control of mDia2 Localization and Function in Cytokinesis
Rho and Anillin-dependent Control of mDia2 Localization and Function in Cytokinesis
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DOI：
10.1091/mbc.e10-04-0324
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发表时间：
2010-09-15
影响因子：
3.3
通讯作者：
Narumiya, Shuh
中科院分区：
文献类型：
--
作者：
Watanabe, Sadanori;Okawa, Katsuya;Narumiya, Shuh
透明质相关的形成因子mDia是一种肌动蛋白成核/聚合因子，在小GTPase Rho下游发挥作用。虽然Rho在胞质分裂中起关键作用，但Rho效应子和细胞骨架的其他调节因子如何共同工作来完成这一过程仍然是难以捉摸的。本研究以mDia 2为研究对象，分析了其在NIH 3 T3细胞胞质分裂中的定位机制。我们发现，靶向mDia 2的切割沟不仅需要它的结合RhoA，但它的透明抑制结构域（DID）。然后，我们使用含有后一个结构域的片段作为诱饵进行下拉测定，并将苯胺醛鉴定为新的mDia 2相互作用伴侣。苯胺结合与mDia 2的透明自动调节结构域（DAD）在其自动抑制相互作用中竞争。一系列RNA干扰和功能拯救实验表明，除了Rho GTP酶介导的激活外，mDia 2和苯胺之间的相互作用是mDia 2在胞质分裂中的定位和功能所必需的。
Diaphanous-related formin, mDia, is an actin nucleation/polymerization factor functioning downstream of the small GTPase Rho. Although Rho is critically involved in cytokinesis, it remains elusive how Rho effectors and other regulators of cytoskeletons work together to accomplish this process. Here we focused on mDia2, an mDia isoform involved in cytokinesis of NIH 3T3 cells, and analyzed mechanisms of its localization in cytokinesis. We found that targeting of mDia2 to the cleavage furrow requires not only its binding to RhoA but also its diaphanous-inhibitory domain ( DID). We then performed pulldown assays using a fragment containing the latter domain as a bait and identified anillin as a novel mDia2 interaction partner. The anillin-binding is competitive with the diaphanous autoregulatory domain ( DAD) of mDia2 in its autoinhibitory interaction. A series of RNA interference and functional rescue experiments has revealed that, in addition to the Rho GTPase-mediated activation, the interaction between mDia2 and anillin is required for the localization and function of mDia2 in cytokinesis.