Role for Gcs1p in regulation of Arl1p at trans-Golgi compartments
Role for Gcs1p in regulation of Arl1p at trans-Golgi compartments
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DOI：
10.1091/mbc.e05-01-0023
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发表时间：
2005-09-01
影响因子：
3.3
通讯作者：
Lee, FJS
中科院分区：
文献类型：
--
作者：
Liu, YW;Huang, CF;Lee, FJS
ADP核糖基化因子（ARF）和ARF样（ARL）蛋白是ARF家族的成员，它们是几种不同囊泡运输途径的关键组分。ARF在没有GTP酶激活蛋白（GAP）的帮助下几乎没有或没有可检测到的GTP酶活性。在这里，我们证明酵母Gcs 1 p在体外对Arl 1 p和Arf 1 p表现出GAP活性，并且Arl 1 p可以以GTP依赖性的方式与Gcs 1 p相互作用。Arl 1 p在高尔基体和胞质中均被观察到，并以GTP依赖的方式从胞质中被招募到膜上。在gcs 1突变细胞中，Arl 1 p在胞质溶胶中相对于trans-Golgi的分数小于它在野生型细胞中。增加Gcs 1 p水平使分布恢复到野生型细胞的分布。Arl 1 p和Gcs 1 p都影响Arl 1 p效应子Imh 1 p的分布。我们的数据是一致的结论，Arl 1 p的运动在trans-Golgi和胞质溶胶之间的动态平衡，和Arl 1 p从细胞膜的释放需要结合GTP的水解，这是加速GCS 1 p。
ADP-ribosylation factor (ARF) and ARF-like (ARL) proteins are members of the ARF family, which are critical components of several different vesicular trafficking pathways. ARFs have little or no detectable GTPase activity without the assistance of a GTPase-activating protein (GAP). Here, we demonstrate that yeast Gcs1p exhibits GAP activity toward Arl1p and Arf1p in vitro, and Arl1p can interact with Gcs1p in a GTP-dependent manner. Arl1p was observed both on trans-Golgi and in cytosol and was recruited from cytosol to membranes in a GTP-dependent manner. In gcs1 mutant cells, the fraction of Arl1p in cytosol relative to trans-Golgi was less than it was in wild-type cells. Increasing Gcs1p levels returned the distribution toward that of wild-type cells. Both Arl1p and Gcs1p influenced the distribution of Imh1p, an Arl1p effector. Our data are consistent with the conclusion that Arl1p moves in a dynamic equilibrium between trans-Golgi and cytosol, and the release of Arl1p from membranes in cells requires the hydrolysis of bound GTP, which is accelerated by Gcs1p.