Involved in the transport of biosynthetic membrane proteins from the prevacuolar/endosomal compartment to the vacuole. Involved in 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 (By similarity). Plays a role in regulating nuclear envelope (NE) morphology and nuclear integrity, particularly during spindle pole body (SPB) extrusion or insertion through the NE, and perhaps during karyokinesis (PubMed:28242692). ATP + H2O = ADP + H(+) + phosphate Slow growth rates of spores and severe nuclear envelope (NE) morphology defects (PubMed:28242692). Asymmetric and even failed karyokinesis (PubMed:28242692). Overgrowth of nuclear membranes, so-called karmellae, in cells with daughter spindle pole bodies (SPBs) that often fail to separate normally or display extensive delays in separation (PubMed:28242692). Large fenestrations through both the inner and outer nuclear membranes and abnormal nuclear integrity, i.e. leaking nuclei (PubMed:28242692). Extensive whorls of disorganized tubulo-vesicular membranes that are topologically continuous with the adjacent karmellae (PubMed:28242692). Decreased number of nuclear pore complexes (NPCs) (PubMed:28242692). Simultaneous knockout of cmp7 or lem2 suppresses the slow growth rates of spores and severe nuclear envelope (NE) morphology defects (PubMed:28242692). Belongs to the AAA ATPase family.