Yip1A regulates the COPI-independent retrograde transport from the Golgi complex to the ER
Yip1A regulates the COPI-independent retrograde transport from the Golgi complex to the ER
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DOI：
10.1242/jcs.043414
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发表时间：
2009-07-01
影响因子：
4
通讯作者：
Murata, Masayuki
中科院分区：
文献类型：
--
作者：
Kano, Fumi;Yamauchi, Shinobu;Murata, Masayuki
Yip 1A是酵母Yip 1 p的哺乳动物同源物，是一种多跨膜蛋白，被认为参与内质网（ER）和高尔基体之间的运输。然而，Yip 1A在哺乳动物细胞中的确切作用仍不清楚。我们在这里表明，内源性Yip 1A是本地化的ER-高尔基体中间室（ERGIC）。通过RNAi敲低Yip 1A不会诱导高尔基体、ER或ERGIC的形态学变化。通过分析大量的细胞内转运途径，我们发现Yip 1A敲低延迟了滋贺毒素从高尔基体到内质网的转运，但不影响VSVGts 045的顺行转运。我们还发现，对应于Yip 1A的N-末端结构域的重组蛋白抑制了GFP标记的半乳糖基转移酶GT-GFP的COPI依赖性逆行转运，但不抑制p58/ERGIC 53的COPI依赖性逆行转运。此外，我们发现Yip 1A敲低导致Rab 6从膜上解离。这些结果表明，Yip 1A在从高尔基体到ER的COPI非依赖性逆行转运中发挥作用，并调节Rab 6的膜募集。
Yip1A, a mammalian homologue of yeast Yip1p, is a multispanning membrane protein that is considered to be involved in transport between the endoplasmic reticulum (ER) and the Golgi. However, the precise role of Yip1A in mammalian cells remains unclear. We show here that endogenous Yip1A is localized to the ER-Golgi intermediate compartment (ERGIC). Knockdown of Yip1A by RNAi did not induce morphological changes in the Golgi, ER, or ERGIC. By analyzing a number of intracellular transport pathways, we found that Yip1A knockdown delayed the transport of Shiga toxin from the Golgi to the ER, but did not affect the anterograde transport of VSVGts045. We also found that a recombinant protein that corresponded to the N-terminal domain of Yip1A inhibited the COPI-independent retrograde transport of GFP-tagged galactosyltransferase, GT-GFP, but not the COPI-dependent retrograde transport of p58/ERGIC53. Furthermore, we found that Yip1A knockdown resulted in the dissociation of Rab6 from the membranes. These results suggested that Yip1A has a role in COPI-independent retrograde transport from the Golgi to the ER and regulates the membrane recruitment of Rab6.