Vps51p mediates the association of the GARP (Vps52/53/54) complex with the late Golgi t-SNARE Tlg1p
Vps51p mediates the association of the GARP (Vps52/53/54) complex with the late Golgi t-SNARE Tlg1p
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DOI：
10.1091/mbc.e02-10-0654
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发表时间：
2003-04-01
影响因子：
3.3
通讯作者：
Stevens, TH
中科院分区：
文献类型：
--
作者：
Conibear, E;Cleck, JN;Stevens, TH
多亚单位系栓复合物可能有助于膜融合事件的特异性，通过在促进SNARE组装的初始识别事件中将运输囊泡与其靶膜连接起来。然而，将栓系因子与囊泡融合机制的其他组成部分联系起来的相互作用在很大程度上仍然未知。我们之前已经确定了高尔基定位复合体（vp52 /53/54复合体）的三个亚基，这是向晚期高尔基逆行运输所必需的。该复合物与晚期高尔基体中发现的Rab和SNARE蛋白相互作用，并与另外两种多亚基拴系复合物：COG复合物和外囊有关。这里我们发现vp552 /53/54复合体有一个额外的亚基vp551。这四聚体GARP（高尔基相关逆行蛋白）复合体的所有四个成员都是两种不同的逆行运输途径所必需的，从早期和晚期内体回到TGN。Vps51突变体表现出一种独特的表型，表明其具有调节作用。事实上，我们发现vp51p介导vp552 /53/54与t-SNARE Tlg1p之间的相互作用。因此，这种小的螺旋状蛋白与t-SNARE的保守n端结构域的结合为系结和融合机制的组成部分之间提供了关键的联系。
Multisubunit tethering complexes may contribute to the specificity of membrane fusion events by linking transport vesicles to their target membrane in an initial recognition event that promotes SNARE assembly. However, the interactions that link tethering factors to the other components of the vesicle fusion machinery are still largely unknown. We have previously identified three subunits of a Golgi-localized complex (the Vps52/53/54 complex) that is required for retrograde transport to the late Golgi. This complex interacts with a Rab and a SNARE protein found at the late Golgi and is related to two other multisubunit tethering complexes: the COG complex and the exocyst. Here we show that the Vps52/53/54 complex has an additional subunit, Vps51p. All four members of this tetrameric GARP (Golgi-associated retrograde protein) complex are required for two distinct retrograde transport pathways, from both early and late endosomes, back to the TGN. vps51 mutants exhibit a distinct phenotype suggestive of a regulatory role. Indeed, we find that Vps51p mediates the interaction between Vps52/53/54 and the t-SNARE Tlg1p. The binding of this small, coiled-coil protein to the conserved N-terminal domain of the t-SNARE therefore provides a crucial link between components of the tethering and the fusion machinery.