Dynamic, Rho1p-dependent localization of Pkc1p to sites of polarized growth.
Dynamic, Rho1p-dependent localization of Pkc1p to sites of polarized growth.
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发表时间：
2000-08
影响因子：
4
通讯作者：
P. D. Andrews;M. Stark
中科院分区：
文献类型：
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作者：
P. D. Andrews;M. Stark
在真核生物中，Rho gtpase及其效应物是肌动蛋白细胞骨架、膜运输和分泌、细胞生长、细胞周期进程和细胞分裂的关键调节因子。出芽酵母Pkc1p是一种参与细胞壁生物合成和细胞骨架极性的蛋白激酶c样酶，在结构和功能上与哺乳动物细胞的rho相关激酶（PRK/ROCK）相关。在本研究中，使用GFP融合（Pkc1p-GFP）在活细胞中监测Pkc1p的定位。Pkc1p-GFP在极化生长位点表现出动态的时空定位。在细胞周期的早期，Pkc1p-GFP在芽前部位和芽尖被发现，随着细胞的进一步发展，Pkc1p-GFP变得离位，最终在母女芽颈周围以一个不完整的环重新定位，直到细胞分离。芽定位依赖于动作蛋白，但颈部Pkc1p-GFP的稳定性不依赖于动作蛋白，尽管两个位点的定位都需要Rho1p的功能。此外，Pkc1p-GFP在细胞壁损伤后表现出快速的重新定位。这些结果表明，Pkc1p在极化生长和细胞壁应激反应中的作用是通过其定位的动态变化介导的，并表明Pkc1p在细胞质分裂中的潜在作用。
In eukaryotes, the Rho GTPases and their effectors are key regulators of the actin cytoskeleton, membrane trafficking and secretion, cell growth, cell cycle progression and cytokinesis. Budding yeast Pkc1p, a protein kinase C-like enzyme involved in cell wall biosynthesis and cytoskeletal polarity, is structurally and functionally related to the Rho-associated kinases (PRK/ROCK) of mammalian cells. In this study, localization of Pkc1p was monitored in live cells using a GFP fusion (Pkc1p-GFP). Pkc1p-GFP showed dynamic spatial and temporal localization at sites of polarized growth. Early in the cell cycle, Pkc1p-GFP was found at the pre-bud site and bud tips, becoming delocalized as the cell progressed further and finally relocalizing around the mother-daughter bud neck in an incomplete ring, which persisted until cell separation. Bud localization was actin-dependent but stability of Pkc1p-GFP at the neck was actin-independent, although localization at both sites required functional Rho1p. In addition, Pkc1p-GFP showed rapid relocalization after cell wall damage. These results suggest that the roles of Pkc1p in both polarized growth and the response to cell wall stress are mediated by dynamic changes in its localization, and suggest an additional potential role in cytokinesis.