Phosphatidylinositol 3-kinase beta subunit (PI3Kβ)

Phosphatidylinositol 3-kinase beta (PI3Kβ) is a class IA PI3K that functions as an obligate heterodimer composed of a p110β catalytic subunit and a regulatory subunit (commonly p85, but also p55 or p50). It catalyzes the phosphorylation of phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P₂] to generate phosphatidylinositol-(3,4,5)-trisphosphate [PI(3,4,5)P₃], a key lipid second messenger. Unlike other class I isoforms, PI3Kβ can be activated by both RTKs and GPCRs, and it also interacts with small GTPases like Rac1(GTP). It plays a role in cell metabolism, survival, proliferation, and motility, and is especially important in spermatogenesis, macrophage function, osteoclast development/function, neutrophil activity, and platelet activation/thrombosis regulation. It is implicated in cancer progression, especially PTEN-deficient tumors.

PI3Kβ inhibitors