Phosphoinositide 3-kinase beta (PI3Kβ)

Phosphoinositide 3-kinase beta (PI3Kβ) is an isoform of the class I PI3Ks, a family of intracellular lipid kinases that play central roles in transducing signals from cell surface receptors to regulate diverse cellular processes. PI3Kβ is functionally unique among PI3Ks due to its ability to integrate and respond synergistically to signals from receptor tyrosine kinases (RTKs), G-protein coupled receptors (GPCRs), and Rho-family GTPases. It phosphorylates the D-3 position of the inositol ring of phosphatidylinositol lipids at the plasma membrane, generating second messengers such as phosphatidylinositol-(3,4)-bisphosphate [PI(3,4)P₂] and phosphatidylinositol-(3,4,5)-trisphosphate [PI(3,4,5)P₃]. These lipids recruit signaling proteins with pleckstrin homology (PH) domains or other lipid-binding motifs to membranes where they regulate cell growth, proliferation, differentiation, motility, survival, and apoptosis resistance. Dysregulation or mutation within the broader class I PI 3 kinase pathway—including aberrant activity/expression of specific isoforms like β—has been implicated in various cancers due to effects on proliferation/survival/invasion.

Other names

PI3K betaPI3K-betaPI3KBPIK3CB

Inhibition of PI3Kβ activity