Structure and function of human Vps20 and Snf7 proteins.

摘要: Snf7p (sucrose non-fermenting) and Vps20p (vacuolar protein-sorting) are small coil-coiled proteins involved in yeast MVB (multivesicular body) structure, formation function. In the present study, we report identification of three human homologues Snf7p, designated hSnf7-1, hSnf7-2 hSnf7-3, a single homologue, hVps20, that may have similar roles humans. Immunofluorescence studies showed hSnf7-1 hSnf7-3 localized large vesicular structures also co-localized with late endosomal/lysosomal induced by overexpressing an ATPase-defective Vps4-A mutant. contrast, overexpressed hVps20 typical endosomal membrane-staining pattern, co-expression Snf7-1 dispersed Snf7-staining vesicles. Interestingly, overexpression both hSnf7 post-endosomal defect cholesterol sorting. To explore possible protein-protein interactions involving proteins, used information from genomic showing can interact Using glutathione S-transferase-capture approach several mammalian such Snf7p-interacting found all hSnf7s interacted mouse AIP1 [ALG-2 (apoptosis-linked gene 2) interacting protein 1], Bro1p [BCK1 (bypass C kinase)-like resistance to osmotic shock]-containing cellular vacuolization apoptosis. Whereas mapping experiments N-terminus containing Bro1 alpha-helical domain were required for interaction did not another Bro1-containing molecule, rhophilin-2. Co-immunoprecipitation confirmed vivo AIP1. Additional immunofluorescence recruited cytosolic Snf7-induced vacuolar-like structures. Together these results suggest Vps20, Snf7 like their counterparts, play