Regulation of Gic2 localization and function by phosphatidylinositol 4,5-bisphosphate during the establishment of cell polarity in budding yeast
Regulation of Gic2 localization and function by phosphatidylinositol 4,5-bisphosphate during the establishment of cell polarity in budding yeast
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DOI：
10.1074/jbc.m708178200
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发表时间：
2008-05-23
影响因子：
4.8
通讯作者：
Guo, Wei
中科院分区：
文献类型：
--
作者：
Orlando, Kelly;Zhang, Jian;Guo, Wei
细胞极性的建立对于从芽殖酵母中的不对称细胞生长到神经元中的神经突形成的广泛的生物过程是重要的。在酿酒酵母中，小的GTd-Cdc 42控制着极化肌动蛋白的组织和胞吐作用。Gic 2是一种Cdc 42效应子，靶向芽尖，在早期芽形成中发挥重要作用。GTP结合的Cdc 42通过位于Gic 2 N端的Cdc 42/Rac相互作用结合结构域与Gic 2相互作用，并在芽萌发期间激活Gic 2。在这里，我们确定了一个多元区域Gic 2相邻的Cdc 42/Rac相互作用的结合结构域，直接与磷脂酰肌醇4，5-二磷酸在质膜。我们证明，这种相互作用是必要的极化本地化的Gic 2的芽尖，是重要的Gic 2在细胞极化的功能。我们建议，磷脂酰肌醇4，5-二磷酸和Cdc 42采取一致行动，以调节极化定位和功能的Gic 2极化细胞生长过程中的芽殖酵母。
Establishment of cell polarity is important for a wide range of biological processes, from asymmetric cell growth in budding yeast to neurite formation in neurons. In the yeast Saccharomyces cerevisiae, the small GTPase Cdc42 controls polarized actin organization and exocytosis toward the bud. Gic2, a Cdc42 effector, is targeted to the bud tip and plays an important role in early bud formation. The GTP-bound Cdc42 interacts with Gic2 through the Cdc42/Rac interactive binding domain located at the N terminus of Gic2 and activates Gic2 during bud emergence. Here we identify a polybasic region in Gic2 adjacent to the Cdc42/Rac interactive binding domain that directly interacts with phosphatidylinositol 4,5-bisphosphate in the plasma membrane. We demonstrate that this interaction is necessary for the polarized localization of Gic2 to the bud tip and is important for the function of Gic2 in cell polarization. We propose that phosphatidylinositol 4,5-bisphosphate and Cdc42 act in concert to regulate polarized localization and function of Gic2 during polarized cell growth in the budding yeast.