Function
Vacuolar protein sorting-associated protein (Vps) are part of Endosomal Sorting Complex Required for Transport (ESCRT) that performs the topologically unique membrane bending and scission reaction away from the cytoplasm. This process is required for the multivesicular body pathway, cytokinesis and HIV budding. There are five distinct ESCRT complexes (0,I,II,III,Vps4) with distinct functions[1].
- Vps4, Vps4A, Vps4B complex catalyzes the disassembly of the ESCRT-III filament in an ATP-driven reaction. Vps4 proteins are required for centrosome and spindle maintenance[2].
- Vps9A activates Rab5 to GTP-bound form[3].
- Vps15 may function as a G protein β subunit at the endosome [4].
- Vps23 is involved in appropriate sorting of receptors within the yast endocytic pathway and is part of the ESCRT-I complex[5]
- Vps25 is part of the ESCRT-II complex which contains two copies of the protein. It induces a conformational switch that converts inactive Vps20 into an active nucleator for Snf7 oligomerization[6].
- Vps26A and Vps26B are part of the Vps29-Vps35-Vps26 retromer which mediates transport of transmembrane proteins from endosomes to the trans-Golgi network[7].
- Vps27 is part of the ESCRT-0 complex
- Vps36 is part of the ESCRT-II complex
Disease
Relevance
Vps25 in Drosophila possesses several properties of tumor repressor[8].
Structural highlights
