The Vps27p-Hse1p complex binds ubiquitin and mediates endosomal protein sorting
The Vps27p-Hse1p complex binds ubiquitin and mediates endosomal protein sorting
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DOI：
10.1038/ncb815
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发表时间：
2002-07-01
影响因子：
21.3
通讯作者：
Piper, RC
中科院分区：
文献类型：
--
作者：
Bilodeau, PS;Urbanowski, JL;Piper, RC
在酿酒酵母的液泡中降解的膜蛋白被分选成离散的腔内囊泡，类似于多囊泡体（MVB）的内膜。最近，已经表明泛素（Ub）的附着介导分选进入内腔膜（1）。我们描述了一个复杂的Vps 27 p和Hse 1 p，定位到内体隔室，并需要高尔基体蛋白的回收，腔膜的形成和泛素化的蛋白到这些膜的排序。Vps 27 p-Hse 1 p复合物与Ub结合，需要多个Ub相互作用基序（UIM）。这些基序的突变导致泛素化蛋白质进入液泡腔的分选中的特定缺陷。然而，高尔基体蛋白的回收和内腔膜的产生在DeltaUIM突变体中正常进行。这些数据支持一种模型，其中Vps 27 p-Hse 1 p复合物在内体具有多种功能，其中之一是作为泛素化膜蛋白降解的分选受体。
Membrane proteins that are degraded in the vacuole of Saccharomyces cerevisiae are sorted into discrete intralumenal vesicles, analogous to the internal membranes of multi-vesiculated bodies (MVBs). Recently, it has shown that the attachment of ubiquitin (Ub) mediates sorting into lumenal membranes(1). We describe a complex of Vps27p and Hse1p that localizes to endosomal compartments and is required for the recycling of Golgi proteins, formation of lumenal membranes and sorting of ubiquitinated proteins into those membranes. The Vps27p-Hse1p complex binds to Ub and requires multiple Ub Interaction Motifs (UIMs). Mutation of these motifs results in specific defects in the sorting of ubiquitinated proteins into the vacuolar lumen. However, the recycling of Golgi proteins and the generation of lumenal membranes proceeds normally in DeltaUIM mutants. These data support a model in which the Vps27p-Hse1p complex has multiple functions at the endosome, one of which is as a sorting receptor for ubiquitinated membrane proteins destined for degradation.