Membrane protein recycling systems are essential for maintenance of the endosome-lysosome system. In yeast, retromer and Snx4 coat complexes are recruited to the endosomal surface where they recognize cargos. They sort cargo and deform the membrane into recycling tubules that bud from the endosome and target to the Golgi. Here, we reveal that the SNX-BAR protein, Mvp1, mediates an endosomal recycling pathway which is mechanistically distinct from the retromer and Snx4 pathways. Mvp1 deforms the endosomal membrane and sorts cargos containing a specific sorting motif into a membrane tubule. Subsequently, Mvp1 recruits the dynamin-like GTPase Vps1 to catalyze membrane scission and release of the recycling tubule. Similarly, SNX8, the human homolog of Mvp1, which has been also implicated in Alzheimer's disease, mediates formation of an endosomal recycling tubule. Thus, we present evidence for a novel endosomal retrieval pathway that is conserved from yeast to humans.

中文翻译：

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PX-BAR 蛋白 Mvp1/SNX8 和动力蛋白样 GTPase Vps1 驱动内体循环

膜蛋白再循环系统对于维持内体-溶酶体系统至关重要。在酵母中，逆转录酶和 Snx4 外套复合物被招募到它们识别货物的内体表面。他们对货物进行分类并将膜变形为从内体发芽并靶向高尔基体的循环小管。在这里，我们揭示了 SNX-BAR 蛋白 Mvp1 介导了一种在机制上不同于逆转录酶和 Snx4 通路的内体循环通路。Mvp1 使内体膜变形并将含有特定分类基序的货物分类到膜小管中。随后，Mvp1 募集类动力蛋白 GTPase Vps1 来催化膜断裂和循环小管的释放。同样，Mvp1 的人类同源物 SNX8 也与阿尔茨海默病有关，介导内体循环小管的形成。因此，我们提供了从酵母到人类保守的新型内体修复途径的证据。