The PI(3,5)P2 regulatory complex regulates both the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2). Required for autophagy (By similarity). Component of the PI(3,5)P2 regulatory complex at least composed of ATG18, SAC/FIG4, FAB1 and VAC14. Peripheral membrane protein of pre-autophagosomal structure (PAS) and vacuole. The first protein part may form a beta-propeller domain involved in specific binding to phosphatidylinositol 3,5-bisphosphate (PIP2), leading to the association of the protein to the membrane. Belongs to the WD repeat PROPPIN family.