The PI(3,5)P2 regulatory complex regulates both the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2). Positively regulates FAB1 kinase activity. Major activator of FAB1 during hyperosmotic shock and can elevate levels of PtdIns(3,5)P2 in the absence of VAC14 and FIG4. Directly involved in vacuolar membrane scission. Required for normal vacuole acidification, inheritance and morphology. Component of the PI(3,5)P2 regulatory complex, composed of ATG18, FIG4, FAB1, VAC14 and VAC7. VAC14 nucleates the assembly of the complex and serves as a scaffold. N-glycosylated.