Phosphatidylinositol 3-kinase catalytic subunit beta isoform (PI3Kβ)

Phosphatidylinositol 3-kinase catalytic subunit beta isoform (PI3Kβ, gene symbol PIK3CB) is a class IA phosphoinositide 3-kinase enzyme that phosphorylates phosphatidylinositol (4,5)-bisphosphate to generate phosphatidylinositol (3,4,5)-trisphosphate (PIP3), a key signaling lipid. PI3Kβ acts downstream of various cell surface receptors—including receptor tyrosine kinases, GPCRs, and integrins—and is involved in mediating diverse cellular responses such as growth, proliferation, migration, and survival. While PI3Kβ is ubiquitously expressed, it plays crucial roles in insulin signaling, cardiovascular homeostasis, and inflammation. In cancer, PI3Kβ is especially important in tumors with PTEN loss, as these may become dependent on PI3Kβ for activating the PI3K/Akt pathway. PI3Kβ is an established drug target, with several selective inhibitors under clinical investigation for cancer and other diseases[4][5][7].

Other names

PI3K betaPI3Kβp110βPIK3CB (gene symbol)Phosphatidylinositol 4,5-bisphosphate 3-kinase beta

Inhibition of PI3Kβ catalytic activity to downregulate PI3K/Akt/mTOR signaling Reduction of phosphatidylinositol (3,4,5)-trisphosphate (PIP3) production Modulation of downstream cell survival and proliferation pathways