Cyk3, a novel SH3-domain protein, affects cytokinesis in yeast
Cyk3, a novel SH3-domain protein, affects cytokinesis in yeast
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DOI：
10.1016/s0960-9822(00)00626-6
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发表时间：
2000-07-27
期刊：
影响因子：
9.2
通讯作者：
Chant, J
中科院分区：
文献类型：
--
作者：
Korinek, WS;Bi, E;Chant, J
胞质分裂需要细胞骨架和分泌物的大规模重组以完成一个细胞分裂为两个。在芽殖酵母酿酒酵母中，IQGAP相关蛋白Iqg 1（Cyk 1）促进细胞动力学肌动蛋白环的形成，并且是胞质分裂和活力所必需的[1-3]。由于肌动蛋白环对胞质分裂或活力不是必需的，Iqg 1必须通过另一种机制起作用[4]。为了揭示这一机制，进行了iqg 1致死表型的高拷贝抑制子的筛选。CYK 3抑制了IQG 1在活力和胞质分裂中的需求，而没有恢复肌动蛋白环，表明CYK 3通过肌动球蛋白环独立途径促进胞质分裂。CYK 3编码一种新的SH 3结构域蛋白，该蛋白与肌动蛋白环和母芽颈相关，CYK 3缺失细胞具有畸形的母芽颈，胞质分裂缺陷。在cyk 3无效株，肌动蛋白重排与胞质分裂出现正常，这表明表型反映了分泌靶向或隔膜合成的缺陷。单独缺失cyk 3或hof 1会导致轻度细胞动力学表型[5-7]，但缺失两种基因会导致致死性和完全的细胞动力学阻断，表明功能重叠。因此，Cyk 3似乎对胞质分裂很重要，并可能在Iqg 1的下游起作用，（C）2000 Elsevier Science Ltd.保留所有权利。
Cytokinesis requires the wholesale reorganization of the cytoskeleton and secretion to complete the division of one cell into two. In the budding yeast Saccharomyces cerevisiae, the IQGAP-related protein Iqg1 (Cyk1) promotes cytokinetic actin ring formation and is required for cytokinesis and viability [1-3]. As the actin ring is not essential for cytokinesis or viability, Iqg1 must act by another mechanism [4]. To uncover this mechanism, a screen for high-copy suppressors of the iqg1 lethal phenotype was performed. CYK3 suppressed the requirement for IQG1 in viability and cytokinesis without restoration of the actin ring, demonstrating that CYK3 promotes cytokinesis through an actomyosin-ring independent pathway. CYK3 encodes a novel SH3-domain protein that was found in association with the actin ring and the mother-bud neck, cyk3 null cells had misshapen mother-bud necks and were deficient in cytokinesis. In the cyk3 null strain, actin rearrangements associated with cytokinesis appeared normal, suggesting that the phenotype reflects a defect in secretory targeting or septal synthesis. Deletion of either cyk3 or hof1 alone results in a mild cytokinetic phenotype [5-7], but deletion of both genes resulted in lethality and a complete cytokinetic block, suggesting overlapping function. Thus, Cyk3 appears to be important for cytokinesis and acts potentially downstream of Iqg1, (C) 2000 Elsevier Science Ltd. All rights reserved.