Enables 1-phosphatidylinositol-3-kinase activity. Acts upstream of or within several processes, including autophagosome organization; negative regulation of zinc ion transmembrane transport; and phosphatidylinositol-3-phosphate biosynthetic process. Predicted to be located in several cellular components, including clathrin-coated vesicle; nucleoplasm; and trans-Golgi network. Predicted to be part of phosphatidylinositol 3-kinase complex. Predicted to be active in cytoplasm and plasma membrane. Orthologous to human PIK3C2A (phosphatidylinositol-4-phosphate 3-kinase catalytic subunit type 2 alpha). [provided by Alliance of Genome Resources, Apr 2022]