A tethering complex dimer catalyzes trans-SNARE complex formation in intracellular membrane fusion.
A tethering complex dimer catalyzes trans-SNARE complex formation in intracellular membrane fusion.
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DOI：
10.4161/bioa.20359
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发表时间：
2012-02-01
期刊：
影响因子：
--
通讯作者：
Peters C
中科院分区：
文献类型：
--
作者：
Kulkarni A;Alpadi K;Namjoshi S;Peters C
SNARE复合物介导内膜系统中的膜融合。它们由四个螺旋的卷曲螺旋束组成，命名为Qa、Qb、Qc和R。融合途径中的关键中间体是由位于相对膜中的SNARE组装产生的反式SNARE复合物。在生理系统中，反式SNARE复合物形成和拓扑结构的机制细节在很大程度上仍未得到解决。我们对天然酵母液泡的研究表明，SNARE单独不足以形成反式SNARE复合物，并且该过程需要额外的因子，潜在的系链复合物和Rab GTP酶。在这里，我们报告了一个新的发现，HOPS拴系复合物二聚体催化Rab GTP酶依赖的拓扑优选的QbQcR-Qa反式SNARE复合物的形成。
SNARE complexes mediate membrane fusion in the endomembrane system. They consist of coiled-coil bundles of four helices designated as Qa, Qb, Qc and R. A critical intermediate in the fusion pathway is the trans-SNARE complex generated by the assembly of SNAREs residing in opposing membranes. Mechanistic details of trans-SNARE complex formation and topology in a physiological system remain largely unresolved. Our studies on native yeast vacuoles revealed that SNAREs alone are insufficient to form trans-SNARE complexes and that additional factors, potentially tethering complexes and Rab GTPases, are required for the process. Here we report a novel finding that a HOPS tethering complex dimer catalyzes Rab GTPase-dependent formation of a topologically preferred QbQcR-Qa trans-SNARE complex.