Rab GDP dissociation inhibitor as a general regulator for the membrane association of rab proteins.
Rab GDP dissociation inhibitor as a general regulator for the membrane association of rab proteins.
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DOI：
10.1016/s0021-9258(17)46822-0
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发表时间：
1993-08
期刊：
影响因子：
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通讯作者：
O. Ullrich;H. Stenmark;K. Alexandrov;L. Huber;K. Kaibuchi;Takuya Sasaki;Y. Takai;M. Zerial
中科院分区：
文献类型：
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作者：
O. Ullrich;H. Stenmark;K. Alexandrov;L. Huber;K. Kaibuchi;Takuya Sasaki;Y. Takai;M. Zerial
Rab蛋白包括一个小的gtpase家族，在膜运输中起调节作用。这些蛋白质部分是细胞质的，部分与特定的胞外和内吞细胞器的膜有关。Smg p25A/rab3A GDI是一种抑制GDP与Smg p25A/rab3A、Sec4p和rab11分离的细胞质蛋白，也被发现可以阻止rab3A与膜的结合。在这项研究中，我们用Madin-Darby犬肾细胞渗透细菌毒素streptolysin O来测试rab3A GDI在调节各种小gtp结合蛋白的膜结合中的一般活性。Rab3A GDP解离抑制剂（GDI）从我们测试的所有兔蛋白的膜上去除，并抑制体外翻译的兔蛋白的膜结合。然而，rab3A GDI对含有法酰化半胱氨酸基序的rab5突变蛋白的膜结合作用有限。最后，我们发现，虽然rab3A GDI主要存在于细胞质中，但它也与胞外和内吞途径的室室有关。由于rab3A GDI可以调节多种兔蛋白的膜结合，我们建议将其重新命名为rab GDI。
Rab proteins comprise a family of small GTPases that serve a regulatory role in membrane traffic. These proteins are in part cytosolic and in part associated with the membranes of specific exocytic and endocytic organelles. Smg p25A/rab3A GDI, a cytosolic protein which inhibits the dissociation of GDP from smg p25A/rab3A, Sec4p, and rab11, has also been found to prevent association of rab3A with the membrane. In this study, we have used Madin-Darby canine kidney cells permeabilized with the bacterial toxin streptolysin O to test the general activity of rab3A GDI in modulating the membrane association of various small GTP-binding proteins. Rab3A GDP dissociation inhibitor (GDI) removed from the membrane all rab proteins we have tested and inhibited the membrane binding of in vitro translated rab proteins. However, rab3A GDI had a limited effect on the membrane association of a mutant rab5 protein which contained a farnesylated cysteine motif. Finally, we found that, although rab3A GDI resides primarily in the cytosol, it is also associated with compartments of the exocytic and endocytic pathways. Since rab3A GDI can modulate the membrane association of various rab proteins, we propose to rename it rab GDI.