part of phosphatidylinositol 3-kinase complex PIK3C3-PIK3R4 complex A protein complex capable of phosphatidylinositol 3-kinase activity and containing subunits of any phosphatidylinositol 3-kinase (PI3K) enzyme. These complexes are divided in three classes (called I, II and III) that differ for their presence across taxonomic groups and for the type of their constituents. Catalytic subunits of phosphatidylinositol 3-kinase enzymes are present in all 3 classes; regulatory subunits of phosphatidylinositol 3-kinase enzymes are present in classes I and III; adaptor proteins have been observed in class II complexes and may be present in other classes too. PIK3CA-PIK3R1 complex PI3-kinase p85-subunit alpha- PI3-kinase p110 complex PI3K complex cellular_component GO:0005942 1-phosphatidylinositol 3-kinase complex phosphoinositide 3-kinase complex For discussion of membrane association, please see https://sourceforge.net/p/geneontology/ontology-requests/11559/ extrinsic component of membrane transferase complex, transferring phosphorus-containing groups membrane protein complex