Characterization of novel Rab6-interacting proteins involved in endosome-to-TGN transport
Characterization of novel Rab6-interacting proteins involved in endosome-to-TGN transport
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DOI：
10.1034/j.1600-0854.2002.030406.x
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发表时间：
2002-04-01
期刊：
影响因子：
4.5
通讯作者：
Goud, B
中科院分区：
文献类型：
--
作者：
Monier, S;Jollivet, F;Goud, B
Rab6 GTPase 在高尔基复合体水平调节细胞内转运。使用酵母双杂交筛选，我们分离了两个与哺乳动物细胞中存在的 Rab6 三种亚型（Rab6A、A' 和 B）特异性相互作用的克隆。 cDNA 编码 976 和 1120 个氨基酸的两种蛋白质（计算分子量分别为 112 和 128 kDa），我们将其命名为 Rab6IP2A 和 Rab6IP2B（Rab6 相互作用蛋白 2）。这两种蛋白质可能对应于同一基因的剪接变体。 Rab6IP2 与其他已知蛋白质（包括 Rab 效应子或伴侣）没有显着的同源性。它们普遍表达，主要在细胞质中表达，并在脑细胞质中的高分子复合物中发现。我们证明 Rab6IP2 可以以 Rab6:GTP 依赖的方式募集到高尔基体膜上。任何形式的 Rab6IP2 的过度表达对分泌途径都没有可检测到的影响。相反，在过表达 Rab6IP2 的 Rab6 结合域的细胞中，志贺毒素 B 亚基在质膜和高尔基复合体之间的逆行转运受到部分抑制。我们的数据表明 Rab6IP2s 参与 Rab6A' 调节的途径。
Rab6 GTPase regulates intracellular transport at the level of the Golgi complex. Using the yeast two-hybrid screen, we have isolated two clones that specifically interact with the three isoforms of Rab6 present in mammalian cells (Rab6A, A' and B). The cDNAs encode two proteins of 976 and 1120 amino acids (calculated molecular mass of 112 and 128 kDa, respectively) that we named Rab6IP2A and Rab6IP2B (for Rab6 Interacting Protein 2). The two proteins likely correspond to spliced variants of the same gene. Rab6IP2s have no significant homology with other known proteins, including Rab effectors or partners. They are ubiquitously expressed, mostly cytosolic and found in high molecular mass complexes in brain cytosol. We show that Rab6IP2s can be recruited on Golgi membranes in a Rab6:GTP-dependent manner. The overexpression of any form of Rab6IP2 has no detectable effect on the secretory pathway. In contrast, the retrograde transport of the Shiga toxin B subunit between the plasma membrane and the Golgi complex is partly inhibited in cells overexpressing the Rab6-binding domain of Rab6IP2. Our data suggest that Rab6IP2s is involved in the pathway regulated by Rab6A'.