Cell cycle-dependent phosphorylation of IQGAP is involved in assembly and stability of the contractile ring in fission yeast
Cell cycle-dependent phosphorylation of IQGAP is involved in assembly and stability of the contractile ring in fission yeast
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DOI：
10.1016/j.bbrc.2020.10.043
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发表时间：
2021-01-01
影响因子：
3.1
通讯作者：
Takaine, Masak
中科院分区：
文献类型：
--
作者：
Morita, Rikuri;Numata, Osamu;Takaine, Masak
胞质分裂是细胞分裂的最后一步，在许多真核细胞中，胞质分裂是由内侧肌动球蛋白收缩环（CR）的收缩驱动的。在裂殖酵母裂殖酵母中，IQGAP样蛋白Rng 2是CR组装和收缩所必需的，并且在后期后特异性地与CR中的肌动蛋白丝（F-actin）相互作用。然而，及时激活Rng 2的机制尚未阐明。我们在此通过检测一系列非磷酸化和拟磷酸化rng 2突变株的表型来检验Rng 2的细胞动力学功能受磷酸化调节的假设。在拟磷酸化突变细胞中，CR中的F-肌动蛋白是不稳定的。遗传分析表明，磷酸化的Rng 2参与CR组装与肌球蛋白-II的合作，而拟磷酸化突变衰减的本地化的Rng 2的CR F-肌动蛋白。目前的结果表明，Rng 2在CR组装过程中被磷酸化，然后去磷酸化，这增强了Rng 2和CR F-肌动蛋白之间的相互作用，以稳定环，从而确保安全的胞质分裂。(C)2020爱思唯尔公司All rights reserved.
Cytokinesis is the final step in cell division and is driven by the constriction of the medial actomyosin-based contractile ring (CR) in many eukaryotic cells. In the fission yeast Schizosaccharomyces pombe, the IQGAP-like protein Rng2 is required for assembly and constriction of the CR, and specifically interacts with actin filaments (F-actin) in the CR after anaphase. However, the mechanism that timely activates Rng2 has not yet been elucidated. We herein tested the hypothesis that the cytokinetic function of Rng2 is regulated by phosphorylation by examining phenotypes of a series of non-phosphorylatable and phosphomimetic rng2 mutant strains. In phosphomimetic mutant cells, F-actin in the CR was unstable. Genetic analyses indicated that phosphorylated Rng2 was involved in CR assembly in cooperation with myosin-II, whereas the phosphomimetic mutation attenuated the localization of Rng2 to CR F-actin. The present results suggest that Rng2 is phosphorylated during CR assembly and then dephosphorylated, which enhances the interaction between Rng2 and CR F-actin to stabilize the ring, thereby ensuring secure cytokinesis. (C) 2020 Elsevier Inc. All rights reserved.