EHD1 interacts with retromer to stabilize SNX1 tubules and facilitate endosome-to-golgi retrieval
EHD1 interacts with retromer to stabilize SNX1 tubules and facilitate endosome-to-golgi retrieval
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DOI：
10.1111/j.1600-0854.2007.00652.x
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发表时间：
2007-12-01
期刊：
影响因子：
4.5
通讯作者：
Seaman, Matthew N. J.
中科院分区：
文献类型：
--
作者：
Gokool, Suzanne;Tattersall, Daniel;Seaman, Matthew N. J.
阳离子非依赖性甘露糖6-磷酸受体（CIMPR）的内体到高尔基体的恢复需要逆转录复合物的功能。逆转录聚合物定位于内体并且包含两种不同的亚复合物：结合货物的液泡蛋白分选35/29/26亚复合物和使内体膜微管化的分选连接蛋白（SNX）1/2亚复合物。采用比较蛋白质组学的方法鉴定逆转录酶的上游或下游调控因子。比较来自野生型或逆转录酶缺陷小鼠细胞的内体富集膜的蛋白质谱，以鉴定具有升高或降低的表达水平的蛋白质。Eps 15同源结构域的蛋白质-1（EHD 1）被确定在内体富集的膜组分从retromer缺陷的细胞，并被发现是约三倍上调在retromer的情况下。EHD 1定位于管状和囊泡内体，与retromer部分共定位，并且在体内与retromer相关。EHD 1的核苷酸结合P环的突变导致逆转录酶定位和内体到高尔基体检索的显性负效应，而RNA干扰导致的EHD 1表达的丧失使SNX 1阳性小管不稳定并抑制内体到高尔基体检索。EHD 1和retromer之间的相互作用以及EHD 1稳定SNX 1-小管的需要确立了EHD 1作为内体到高尔基体回收的新的促进组分。
Endosome-to-Golgi retrieval of the cation-independent mannose 6-phosphate receptor (CIMPR) requires the function of the retromer complex. Retromer is localized to endosomes and comprises two distinct sub complexes: the vacuolar protein sorting 35/29/26 sub complex that binds cargo and the sorting nexin (SNX)1/2 sub complex that tubulates endosomal membranes. To identify up- or down-stream regulatory factors of retromer, a comparative proteomic strategy was employed. Protein profiles of endosomally enriched membranes, from either wild-type or retromer-deficient mouse cells, were compared to identify proteins with either elevated or reduced expression levels. Eps15 homology domain-containing protein-1 (EHD1) was identified in endosomally enriched membrane fractions from retromer-deficient cells and was found to be approximately threefold upregulated in the absence of retromer. EHD1 is localized to tubular and vesicular endosomes, partially colocalizes with retromer and is associated with retromer in vivo. Mutation of the nucleotide-binding P-loop of EHD1 results in a dominant-negative effect upon retromer localization and endosome-to-Golgi retrieval, while loss of EHD1 expression by RNA interference destabilizes SNX1-positive tubules and inhibits endosome-to-Golgi retrieval. The interaction between EHD1 and retromer and the requirement for EHD1 to stabilize SNX1-tubules establish EHD1 as a novel facilitating component of endosome-to-Golgi retrieval.