Rab11 is required for trans-Golgi network to plasma membrane transport and a preferential target for GDP dissociation inhibitor
Rab11 is required for trans-Golgi network to plasma membrane transport and a preferential target for GDP dissociation inhibitor
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DOI：
10.1091/mbc.9.11.3241
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发表时间：
1998-11-01
影响因子：
3.3
通讯作者：
Wandinger-Ness, A
中科院分区：
文献类型：
--
作者：
Chen, W;Feng, Y;Wandinger-Ness, A
Rab11 GTP酶定位于高尔基体和循环内体，但其高尔基体相关功能尚不清楚。本研究通过两种独立的方法干扰Rab11的活性，分析了Rab11在胞外转运中的作用。首先，优势干扰蛋白Rab11S25N的表达显著抑制了水疱性口炎病毒(VSV)G蛋白的细胞表面转运，并导致VSV G蛋白在高尔基体中积聚。另一方面，野生型Rab11和激活的Rab11Q70L突变体的表达对VSV G转运无不良影响。接下来，对其功能至关重要的Rab11的膜结合受到GDP解离抑制物(GDI)水平适度增加的干扰。这导致了跨高尔基体网络对细胞表面运输的选择性抑制，而内质网到高尔基体的运输和高尔基体内的运输基本上没有受到影响。野生型Rab11与GDI共表达可特异性逆转这种转运抑制。在相同条件下，另两种胞外Rab蛋白Rab2和Rab8仍与膜结合，其调控的转运步骤不受影响。突变型Rab11S25N和GDI过表达对流感血凝素的细胞表面转运均无影响。这些数据表明，功能性Rab11对于从跨高尔基体网络输出基侧标记而不是顶端标记是关键的，并准确地将Rab11作为过度GDI抑制的敏感靶点。
The rab11 GTPase has been localized to both the Golgi and recycling endosomes; however, its Golgi-associated function has remained obscure. In this study, rab11 function in exocytic transport was analyzed by using two independent means to perturb its activity. First, expression of the dominant interfering rab11S25N mutant protein led to a significant inhibition of the cell surface transport of vesicular stomatitis virus (VSV) G protein and caused VSV G protein to accumulate in the Golgi. On the other hand, the expression of wild-type rab11 or the activating rab11Q70L mutant had no adverse effect on VSV G transport. Next, the membrane association of rab11, which is crucial for its function, was perturbed by modest increases in GDP dissociation inhibitor (GDI) levels. This led to selective inhibition of the trans-Golgi network to cell surface delivery, whereas endoplasmic reticulum-to-Golgi and intra-Golgi transport were largely unaffected. The transport inhibition was reversed specifically by coexpression of wild-type rab11 with GDI. Under the same conditions two other exocytic rab proteins, rab2 and rab8, remained membrane bound, and the transport steps regulated by these rab proteins were unaffected. Neither mutant rab11S25N nor GDI overexpression had any impact on the cell surface delivery of influenza hemagglutinin. These data show that functional rab11 is critical for the export of a basolateral marker but not an apical marker from the trans-Golgi network and pinpoint rab11 as a sensitive target for inhibition by excess GDI.