Required for vesicle-mediated transport. Catalyzes the fusion of transport vesicles within the Golgi cisternae. Is also required for transport from the endoplasmic reticulum to the Golgi stack. Seems to function as a fusion protein required for the delivery of cargo proteins to all compartments of the Golgi stack GRIA2 leads to influence GRIA2 membrane cycling (By similarity). ATP + H2O = ADP + H(+) + phosphate Binds 1 Mg(2+) ion per subunit. Homohexamer. Interacts with GABARAP and GABARAPL2. Interacts with GRIA2. Interacts with PLK2, leading to disrupt the interaction with GRIA2. Interacts with MUSK; may regulate MUSK endocytosis and activity (By similarity). Interacts with CDK16. Phosphorylation at Ser-569 interferes with homohexamerization. Belongs to the AAA ATPase family.