Yeast Cdc42 functions at a late step in exocytosis, specifically during polarized growth of the emerging bud.
Yeast Cdc42 functions at a late step in exocytosis, specifically during polarized growth of the emerging bud.
复制标题
酵母CDC42在胞吐作用的后期发挥作用，特别是在新兴芽的极化生长过程中。
DOI：
10.1083/jcb.200106065
复制
发表时间：
2001-11-12
影响因子：
7.8
通讯作者：
Brennwald, PJ
中科院分区：
文献类型：
--
作者：
Adamo, JE;Moskow, JJ;Gladfelter, AS;Viterbo, D;Lew, DJ;Brennwald, PJ
Rho 家族 GTPase Cdc42 是真核细胞中细胞极性和细胞骨架组织的关键调节因子。在酵母中，Cdc42 在细胞生长极化中的作用包括肌动蛋白细胞骨架的极化，该骨架将分泌囊泡递送至质膜的生长位点。我们现在描述了一种新型温度敏感突变体 cdc42-6，它揭示了 Cdc42 在分泌囊泡对接和融合中的作用，该作用与其在肌动蛋白极化中的作用无关。 cdc42-6突变体可以极化肌动蛋白并将分泌囊泡递送至芽，但无法将这些囊泡与质膜融合。这种缺陷仅在芽形成的早期阶段表现出来，此时生长是高度极化的，并且似乎反映了 Cdc42 在高囊泡吞吐量位点维持最大活性的胞吐机制的要求。 cdc42-6 和胞吐成分突变之间广泛的遗传相互作用支持了这一假设，并表明与 Rho3 的功能重叠，Rho3 也调节肌动蛋白组织和胞吐作用。定位数据表明 cdc42-6 细胞中的缺陷并不在于胞吐器的定位水平。相反，我们建议 Cdc42 作为囊泡对接和融合装置的变构调节剂，以在极化生长位点提供最大功能。
The Rho family GTPase Cdc42 is a key regulator of cell polarity and cytoskeletal organization in eukaryotic cells. In yeast, the role of Cdc42 in polarization of cell growth includes polarization of the actin cytoskeleton, which delivers secretory vesicles to growth sites at the plasma membrane. We now describe a novel temperature-sensitive mutant, cdc42-6, that reveals a role for Cdc42 in docking and fusion of secretory vesicles that is independent of its role in actin polarization. cdc42-6 mutants can polarize actin and deliver secretory vesicles to the bud, but fail to fuse those vesicles with the plasma membrane. This defect is manifested only during the early stages of bud formation when growth is most highly polarized, and appears to reflect a requirement for Cdc42 to maintain maximally active exocytic machinery at sites of high vesicle throughput. Extensive genetic interactions between cdc42-6 and mutations in exocytic components support this hypothesis, and indicate a functional overlap with Rho3, which also regulates both actin organization and exocytosis. Localization data suggest that the defect in cdc42-6 cells is not at the level of the localization of the exocytic apparatus. Rather, we suggest that Cdc42 acts as an allosteric regulator of the vesicle docking and fusion apparatus to provide maximal function at sites of polarized growth.
登录
查看更多内容
影响因子：
64.5
作者：
LIU, H;BRETSCHER, A
通讯作者：
BRETSCHER, A
影响因子：
3.2
作者：
ITO, H;FUKUDA, Y;KIMURA, A
通讯作者：
KIMURA, A
影响因子：
11.4
作者：
Katz, L;Hanson, PI;Brennwald, P
通讯作者：
Brennwald, P
影响因子：
3.3
作者：
Kozminski, KG;Chen, AJ;Drubin, DG
通讯作者：
Drubin, DG
影响因子：
5.3
作者：
Mösch, HU;Köhler, T;Braus, GH
通讯作者：
Braus, GH