The small GTP-binding protein rab6 functions in intra-Golgi transport.
The small GTP-binding protein rab6 functions in intra-Golgi transport.
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DOI：
10.1083/jcb.127.6.1575
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发表时间：
1994-12
影响因子：
7.8
通讯作者：
Goud, B
中科院分区：
文献类型：
--
作者：
Martinez, O;Schmidt, A;Salamero, J;Hoflack, B;Roa, M;Goud, B
Rab 6是与高尔基复合体的膜相关的普遍存在的ras样GTP结合蛋白（Goud，B.，A. Zahraoui，A. Tavitian和J. Saraste。1990.自然（伦敦）。345：553-556;安东尼，C.，C. Cibert，G. Geraud，A.圣玛利亚，B。Maro，V. Mayau，and B.古德。1992.《细胞科学杂志》103：785-796）。我们在小鼠L细胞和人HeLa细胞中瞬时过表达野生型rab 6，GTP（rab 6 Q72 L）和GDP（rab 6 T27 N）结合的突变体rab 6，并分析了可溶性分泌形式的碱性磷酸酶（SEAP）和质膜蛋白，流感病毒的血凝素蛋白（HA）的细胞内转运。野生型rab 6和rab 6 Q72 L的过表达大大降低了这两种标记物在顺式/内侧（α-甘露糖苷酶II阳性）和晚期（唾液酸转移酶阳性）高尔基体区室之间的转运，而不影响从内质网（ER）到顺式/内侧-高尔基体或从反式-高尔基体网络（TGN）到质膜的转运。而rab 6 T27 N的过表达并不影响ER和质膜之间的运输的各个步骤，它引起了明显的延迟分泌，最有可能是由于后期高尔基室的运输标记物的积累。rab 6 Q72 L和rab 6 T27 N的过表达改变了高尔基体的形态以及TGN的形态，如在免疫荧光水平与几个标记物进行评估。我们解释这些结果表明，rab 6控制内高尔基体运输，无论是作为一种抑制剂，在顺行运输或作为一个积极的调节逆行运输。
Rab6 is a ubiquitous ras-like GTP-binding protein associated with the membranes of the Golgi complex (Goud, B., A. Zahraoui, A. Tavitian, and J. Saraste. 1990. Nature (Lond.). 345:553-556; Antony, C., C. Cibert, G. Geraud, A. Santa Maria, B. Maro, V. Mayau, and B. Goud. 1992. J. Cell Sci. 103: 785-796). We have transiently overexpressed in mouse L cells and human HeLa cells wild-type rab6, GTP (rab6 Q72L), and GDP (rab6 T27N) -bound mutants of rab6 and analyzed the intracellular transport of a soluble secreted form of alkaline phosphatase (SEAP) and of a plasma membrane protein, the hemagglutinin protein (HA) of influenza virus. Over-expression of wild-type rab6 and rab6 Q72L greatly reduced transport of both markers between cis/medial (alpha- mannosidase II positive) and late (sialyl-transferase positive) Golgi compartments, without affecting transport from the endoplasmic reticulum (ER) to cis/medial-Golgi or from the trans-Golgi network (TGN) to the plasma membrane. Whereas overexpression of rab6 T27N did not affect the individual steps of transport between ER and the plasma membrane, it caused an apparent delay in secretion, most likely due to the accumulation of the transport markers in late Golgi compartments. Overexpression of both rab6 Q72L and rab6 T27N altered the morphology of the Golgi apparatus as well as that of the TGN, as assessed at the immunofluorescence level with several markers. We interpret these results as indicating that rab6 controls intra-Golgi transport, either acting as an inhibitor in anterograde transport or as a positive regulator of retrograde transport.