PDF(Pubmed)
Abstract：
The IQGAP family of proteins plays a crucial role in cytokinesis across diverse organisms, but the underlying mechanisms are not fully understood. In this study, we demonstrate that IQGAPs in budding yeast, fission yeast, and human cells use a two-domain module to regulate their localization as well as the assembly and disassembly of the actomyosin ring during cytokinesis. Strikingly, the calponin homology domains (CHDs) in these IQGAPs bind to distinct cellular F-actin structures with varying specificity, whereas the non-conserved domains immediately downstream of the CHDs in these IQGAPs all target the division site, but differ in timing, localization strength, and binding partners. We also demonstrate that human IQGAP3 acts in parallel to septins and myosin-IIs to mediate the role of anillin in cytokinesis. Collectively, our findings highlight the two-domain mechanism by which IQGAPs regulate cytokinesis in distantly related organisms as well as their evolutionary conservation and divergence.
摘要：
IQGAP蛋白家族在不同生物体的胞质分裂中起着至关重要的作用。但是潜在的机制还没有完全理解。在这项研究中,我们证明了出芽酵母中的IQGAP，裂殖酵母,和人类细胞使用两个结构域模块来调节它们的定位以及在胞质分裂过程中肌动球蛋白环的组装和拆卸。引人注目的是，这些IQGAP中的钙蛋白同源域（CHD）以不同的特异性与不同的细胞F-肌动蛋白结构结合，而这些IQGAP中CHD下游的非保守域都靶向分裂位点，但是时间不同，本地化强度，和有约束力的合作伙伴。我们还证明了人IQGAP3与septin和肌球蛋白II平行作用，以介导香草醛在胞质分裂中的作用。总的来说，我们的发现强调了IQGAPs调节远亲生物胞质分裂的两结构域机制以及它们的进化保守性和分歧性.
