HOPS initiates vacuole docking by tethering membranes before trans-SNARE complex assembly.
HOPS initiates vacuole docking by tethering membranes before trans-SNARE complex assembly.
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DOI：
10.1091/mbc.e10-01-0044
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发表时间：
2010-07-01
影响因子：
3.3
通讯作者：
Wickner W
中科院分区：
文献类型：
--
作者：
Hickey CM;Wickner W
大型寡聚束缚复合物（例如 exocyst、TRAPP 和 HOPS）与 Rab 和 SNARE 依赖性膜融合有关。本文表明，HOPS 直接束缚带有液泡脂质或 Rab Ypt7p 的脂质体，并且束缚是 HOPS 刺激反式 SNARE 复合物形成和融合的主要机制。液泡同型融合已用所有纯化成分重建：液泡脂质、四种可溶性 N-乙基马来酰亚胺敏感因子附着蛋白受体 (SNARE) 蛋白、Sec17p、Sec18p、Rab Ypt7p 以及六聚体同型融合和液泡蛋白分选复合物 (HOPS)。 HOPS 是一种 Rab 效应器，对 SNARE（可能通过其 Sec1-Munc18 同源亚基 Vps33p）和某些液泡脂质具有直接亲和力。这些纯液泡蛋白中的每一种都是最佳脂蛋白体聚类所必需的，这就提出了哪个是最直接参与的问题。我们现在提出聚类和融合的模型子反应，揭示 HOPS 是束缚的直接推动者。 Rab 和液泡脂质通过支持 HOPS 的膜缔合而有助于束缚。 HOPS通过束缚膜间接促进反式-SNARE复合物的形成，因为合成的脂质体束缚因子聚乙二醇也可以刺激反式-SNARE复合物的形成和融合。 SNARE 进一步稳定了 HOPS 束缚膜的结合。然后，HOPS 保护新形成的反式 SNARE 复合体免遭 Sec17p/Sec18p 分解。
Large oligomeric tethering complexes such as exocyst, TRAPP, and HOPS have been implicated in Rab- and SNARE-dependent membrane fusion. This paper shows that HOPS directly tethers liposomes that bear vacuolar lipids or the Rab Ypt7p and that tethering is the main mechanism by which HOPS stimulates trans-SNARE complex formation and fusion. Vacuole homotypic fusion has been reconstituted with all purified components: vacuolar lipids, four soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, Sec17p, Sec18p, the Rab Ypt7p, and the hexameric homotypic fusion and vacuole protein sorting complex (HOPS). HOPS is a Rab-effector with direct affinity for SNAREs (presumably via its Sec1-Munc18 homologous subunit Vps33p) and for certain vacuolar lipids. Each of these pure vacuolar proteins was required for optimal proteoliposome clustering, raising the question of which was most directly involved. We now present model subreactions of clustering and fusion that reveal that HOPS is the direct agent of tethering. The Rab and vacuole lipids contribute to tethering by supporting the membrane association of HOPS. HOPS indirectly facilitates trans-SNARE complex formation by tethering membranes, because the synthetic liposome tethering factor polyethylene glycol can also stimulate trans-SNARE complex formation and fusion. SNAREs further stabilize the associations of HOPS-tethered membranes. HOPS then protects newly formed trans-SNARE complexes from disassembly by Sec17p/Sec18p.
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影响因子：
3.4
作者：
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通讯作者：
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DOI：
10.1073/pnas.0900755106
发表时间：
2009-10-13
影响因子：
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