Phosphatidylinositol 3-kinase catalytic subunit beta (PI3K-beta (p110β))

Phosphatidylinositol 3-kinase catalytic subunit beta is the Class IA PI3K catalytic isoform p110β that heterodimerizes with p85-type regulatory subunits to phosphorylate phosphatidylinositol 4,5-bisphosphate at the 3-position, generating PIP3 and initiating AKT-dependent signaling cascades that regulate cell growth, proliferation, survival, metabolism, motility, and angiogenesis. It has a unique role in controlling DNA replication through both kinase-dependent signaling (nuclear AKT activation affecting p21Cip and PCNA) and kinase-independent interactions with PCNA that regulate its loading onto chromatin. PI3Kβ also interfaces with GPCR signaling via direct regulation by Gβγ, highlighting its integration of RTK and GPCR inputs within Class I PI3K signaling networks.

Other names

p110βPI3KβClass IA PI3K beta catalytic subunitPhosphoinositide 3-kinase beta catalytic subunit

Competitive inhibition of the ATP-binding site of PI3K catalytic subunits to block PIP3 production, thereby downregulating AKT/PDK1 signaling and downstream proliferative/survival pathways. Isoform-selective inhibition of Class I PI3Ks to modulate specific cellular functions; structural features enable design of isoform-specific inhibitors.