The Vps4p AAA ATPase regulates membrane association of a Vps protein complex required for normal endosome function

摘要: Vps4p is an AAA-type ATPase required for efficient transport of biosynthetic and endocytic cargo from endosome to the lysosome-like vacuole Saccharomyces cerevisiae. mutants that do not bind ATP or are defective in hydrolysis were characterized both vivo vitro. The nucleotide-free ADP-bound form existed as a dimer, whereas ATP-locked state, dimers assembled into decameric complex. This suggests drives cycle association dissociation dimers/decamers. Nucleotide binding also regulated with endosomal compartment vivo. membrane N-terminal coiled-coil motif Vps4p, but deletion domain did affect activity oligomeric assembly protein. Membrane two previously uncharacterized class E Vps proteins, Vps24p Vps32p/Snf7p, was affected by mutations VPS4. Upon inactivation temperature-conditional vps4 mutant, Vps32p/Snf7p rapidly accumulated large membrane-bound Immunofluorescence indicated proteins function at common compartment. Together, data suggest Vps4 catalyzes release (uncoating) membrane-associated protein complex(es) normal morphology sorting endosome.