Dual function of Cyk2, a cdc15/PSTPIP family protein, in regulating actomyosin ring dynamics and septin distribution.
Dual function of Cyk2, a cdc15/PSTPIP family protein, in regulating actomyosin ring dynamics and septin distribution.
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CYK2（CDC15/PSTPIP家族蛋白）的双重功能在调节肌动蛋白环动力学和SEPTIN分布中。
DOI：
10.1083/jcb.143.7.1947
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发表时间：
1998-12-28
期刊：
影响因子：
--
通讯作者：
Li R
中科院分区：
文献类型：
--
作者：
Lippincott J;Li R
我们以前表明，芽殖酵母酿酒酵母组装肌动球蛋白为基础的环，经历了收缩样的大小变化在胞质分裂。为了了解更多关于这个环的生化组成和活性，我们已经表征了Cyk 2 p的体内分布和功能，Cyk 2 p是一种芽殖酵母蛋白，与cdc 15/PSTPIP家族的切割沟蛋白具有显着的序列相似性。表达绿色荧光蛋白（GFP）标记的Cyk 2 p的细胞的视频显微镜显示，Cyk 2 p形成一个双环，在大多数细胞周期中与septins一致。然而，在胞质分裂期间，Cyk 2双环与肌动球蛋白环合并，并表现出依赖于Myo 1 p的收缩样大小变化。相比之下，隔蛋白双环不经历收缩样大小变化，但在胞质分裂期间两个环之间的分离增加。这些观察结果表明，septin的环是动态不同的肌动球蛋白环和Cyk 2 p的两种类型的结构之间的过渡。CYK 2的基因破坏不影响肌动球蛋白环的组装，但在收缩期导致环的快速解体，导致不完全的胞质分裂，这表明Cyk 2 p在调节收缩期间肌动球蛋白环的稳定性方面具有重要的功能。Cyk 2 p的过表达也阻断胞质分裂，最有可能是由于从芽颈的septins的损失，表明Cyk 2 p也可能在调节septins的定位中发挥作用。
We previously showed that the budding yeast Saccharomyces cerevisiae assembles an actomyosin-based ring that undergoes a contraction-like size change during cytokinesis. To learn more about the biochemical composition and activity of this ring, we have characterized the in vivo distribution and function of Cyk2p, a budding yeast protein that exhibits significant sequence similarity to the cdc15/PSTPIP family of cleavage furrow proteins. Video microscopy of cells expressing green fluorescent protein (GFP)-tagged Cyk2p revealed that Cyk2p forms a double ring that coincides with the septins through most of the cell cycle. During cytokinesis, however, the Cyk2 double ring merges with the actomyosin ring and exhibits a contraction-like size change that is dependent on Myo1p. The septin double ring, in contrast, does not undergo the contraction-like size change but the separation between the two rings increases during cytokinesis. These observations suggest that the septin-containing ring is dynamically distinct from the actomyosin ring and that Cyk2p transits between the two types of structures. Gene disruption of CYK2 does not affect the assembly of the actomyosin ring but results in rapid disassembly of the ring during the contraction phase, leading to incomplete cytokinesis, suggesting that Cyk2p has an important function in modulating the stability of the actomyosin ring during contraction. Overexpression of Cyk2p also blocks cytokinesis, most likely due to a loss of the septins from the bud neck, indicating that Cyk2p may also play a role in regulating the localization of the septins.