Involved in the transport of biosynthetic membrane proteins from the prevacuolar/endosomal compartment to the vacuole. Required for multivesicular body (MVB) protein sorting. Catalyzes the ATP-dependent dissociation of class E VPS proteins from endosomal membranes, such as the disassembly of the ESCRT-III complex (PubMed:17468262, PubMed:20663085, PubMed:21810997, PubMed:22258747, PubMed:24812106). May also regulate cell cycle (PubMed:20663085). Required during seed development for the formation of mucilage in seed coat and testa (PubMed:20930567). Involved in the maintenance of Na(+)/K(+) homeostasis under salt stress (PubMed:23580756). Required for cell expansion (PubMed:24385429). ATP + H2O = ADP + H(+) + phosphate Activated by LIP5 and PROS. Monomer or homodimer (in nucleotide-free form). Decamer, dodecamer or tetradecamer of two stacked respective homooligomeric rings (when bound to ATP); the dodecameric form seems to be predominant (By similarity). Interacts with members of the ESCRT-III subcomplex such as LIP5, VPS60-1, VPS2.1, VPS20.1, VPS20.2, VPS24-1, VPS32.1, VPS32.2, CHMP1A and VPS24 (PubMed:17468262, PubMed:19304934, PubMed:20663085, PubMed:24812106, PubMed:25010425). Binds to PROS/At4g24370 (PubMed:24385429). In young trichome vacuole-free cells, present in the cytosol and in the nucleus. In vacuole-containing cells, present in punctae and large speckles corresponding to prevacuolar compartments (PubMed:20663085). Localized in multivesicular body when associated with LIP5 (PubMed:25010425). Mostly expressed in leaves, to a lower extent in seeds, and barely in roots and flowers (at protein level) (PubMed:17468262). Particularly expressed in trichomes (PubMed:20663085). By Pseudomonas syringae pv. tomato strain DC3000 (PstDC3000). The MIT domain serves as an adapter for ESCRT-III proteins. It forms an asymmetric three-helix bundle that binds amphipathic MIM (MIT interacting motif) helices along the groove between MIT helices 2 and 3 present in a subset of ESCRT-III proteins thus establishing the canonical MIM-MIT interaction. In an extended conformation along the groove between helices 1 and 3, also binds to a type-2 MIT interacting motif (MIM2). Normal vacuolar development in early stages of trichome development shortly followed by fragmentation of the large central vacuole which finally disappears completely, associated with the formation of abnormally enlarged late endosomes. Abnormal sorting of vacuolar proteins that are instead secreted. Trichomes contain frequently multiple nuclei (PubMed:20663085). Reduced ESCRT-III disassembly (PubMed:21810997). Blocked vacuolar trafficking (PubMed:22258747). Imbalanced Na(+)/K(+) ratio under salt stress (PubMed:23580756). Belongs to the AAA ATPase family.