phosphatidylinositol 3-kinase complex, class IA class IA PI3K complex 1-phosphatidylinositol-4-phosphate kinase, class IA complex phosphoinositide 3-kinase complex, class IA A class I phosphatidylinositol 3-kinase complex that possesses 1-phosphatidylinositol-4-phosphate 3-kinase activity; comprises a catalytic class IA phosphoinositide 3-kinase (PI3K) subunit and an associated SH2 domain-containing regulatory subunit that is a member of a family of related proteins often called p85 proteins. Through the interaction with the SH2-containing adaptor subunits, Class IA PI3K catalytic subunits are linked to tyrosine kinase signaling pathways. GO:0035030 cellular_component GO:0005943 1-phosphatidylinositol-4-phosphate 3-kinase, class IA complex phosphatidylinositol 3-kinase complex, class I