The PI(3,5)P2 regulatory complex regulates both the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2). Catalyzes the phosphorylation of phosphatidylinositol 3-phosphate on the fifth hydroxyl of the myo-inositol ring, to form phosphatidylinositol 3,5-bisphosphate (PubMed:16492811, PubMed:9811604). Required for endocytic-vacuolar pathway and nuclear migration (PubMed:9751732, PubMed:16492811, PubMed:9811604). The product of the reaction, PI(3,5)P2 is an important regulator of vacuole homeostasis perhaps by controlling membrane flux to and/or from the vacuole (PubMed:9811604, PubMed:9763421). PI(3,5)P2 regulates the transition between trans-SNARE complex formation and vacuole membrane fusion (PubMed:30427760). Hyperosmotic shock-induced increase in the levels of PtdIns(3,5)P2 requires the presence of VAC7, VAC14, and/or FIG4 (PubMed:16492811). a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3-phosphate) + ATP = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,5-bisphosphate) + ADP + H(+) 1,2-dihexadecanoyl-sn-glycero-3-phospho-(1D-myo-inositol-3-phosphate) + ATP = 1,2-dihexadecanoyl-sn-glycero-3-phospho-(1D-myo-inositol-3,5-phosphate) + ADP + H(+) Activated by VAC14 and VAC7. VAC14 acts as a specific osmotic response regulator. 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. Localization to the vacuole membrane requires VAC14 and FIG4. The chaperone-containing TCP1 (CCT) domain is essential for the interaction with the scaffold protein VAC14. The conserved cysteine-rich (CCR) domain contacts intramolecularly the C-terminus, including the kinase domain, and this interaction negatively regulates PI(3) 5-kinase activity. Present with 149 molecules/cell in log phase SD medium.