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. Required for endocytic-vacuolar pathway and nuclear migration. 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. PI(3,5)P2 regulates the transition between trans-SNARE complex formation and vacuole membrane fusion (By similarity). Required for survival under conditions of nitrogen starvation. May have a role in the secretion of pheromone peptides (PubMed:11895483). 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(+) Component of the PI(3,5)P2 regulatory complex, at least composed of fab1, fig4/SPAC1093.03 and vac14/SPBC25H2.03. Vac14 nucleates the assembly of the complex and serves as a scaffold. During cell fusion of opposite mating types, migrates to the isthmus. The chaperone-containing TCP1 (CCT) domain is essential for the interaction with the scaffold protein vac14/SPBC25H2.03. 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.