Roles of Hof1p, Bni1p, Bnr1p, and Myo1p in cytokinesis in Saccharomyces cerevisiae
Roles of Hof1p, Bni1p, Bnr1p, and Myo1p in cytokinesis in Saccharomyces cerevisiae
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DOI：
10.1091/mbc.11.2.593
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发表时间：
2000-02-01
影响因子：
3.3
通讯作者：
Bi, E
中科院分区：
文献类型：
--
作者：
Vallen, EA;Caviston, J;Bi, E
在酿酒酵母中，胞质分裂是通过肌动球蛋白系统和隔膜形成的协同作用而发生的。在这里，我们报告HOF 1，BNI 1和BNR 1在胞质分裂中的作用，重点是Hof 1 p。HOF 1的缺失导致隔形成中的温度敏感性缺陷。在G2/M期，芽颈的母侧形成Hof 1 p环，随后子侧形成环。在末期，Hof 1 p被磷酸化，双环合并成一个单环，轻微收缩，可能与肌动球蛋白结构共定位。隔膜形成后，Hof 1 p分裂成两个环，在细胞分离时消失。Hof 1 p定位依赖于septins，而不是Myo 1 p。合成致死率表明，Bni 1 p和Myo 1 p属于一个功能途径，而Hof 1 p和Bnr 1 p属于另一个。这些结果表明，Hof 1 p可能作为一个适配器连接的初级隔膜合成机械肌动球蛋白系统。肌动球蛋白环的形成不受bni 1 Delta、hof 1 Delta或bnr 1的影响。然而，Myo 1 p收缩受bni 1 Delta的影响，而不受hof 1 Delta或bnr 1 Delta的影响。在缺乏肌动球蛋白收缩的Lbni 1 Delta细胞中，隔膜形成通常是缓慢和不对称的，这表明肌动球蛋白收缩可能为有效的隔膜形成提供方向性。
Cytokinesis in Saccharomyces cerevisiae occurs by the concerted action of the actomyosin system and septum formation. Here we report on the roles of HOF1, BNI1, and BNR1 in cytokinesis, focusing on Hof1p. Deletion of HOF1 causes a temperature-sensitive defect in septum formation. A Hof1p ring forms on the mother side of the bud neck in G2/M, followed by the formation of a daughter-side ring. Around telophase, Hof1p is phosphorylated and the double rings merge into a single ring that contracts slightly and may colocalize with the actomyosin structure. Upon septum formation, Hof1p splits into two rings, disappearing upon cell separation. Hof1p localization is dependent on septins but not Myo1p. Synthetic lethality suggests that Bni1p and Myo1p belong to one functional pathway, whereas Hof1p and Bnr1p belong to another. These results suggest that Hof1p may function as an adapter linking the primary sept-um synthesis machinery to the actomyosin system. The formation of the actomyosin ring is not affected by bni1 Delta, hof1 Delta, or bnr1. However, Myo1p contraction is affected by bni1 Delta but not by hof1 Delta or bnr1 Delta. Ln bni1 Delta cells that lack the actomyosin contraction, septum formation is often slow and asymmetric, suggesting that actomyosin contraction may provide directionality for efficient septum formation.