Phosphatidylinositol 3-kinase catalytic subunit alpha (p110α)

Phosphatidylinositol 3-kinase catalytic subunit alpha (p110α) is a key enzyme within the class IA phosphoinositide 3-kinases. It forms a heterodimeric complex with regulatory subunits such as p85. The enzyme catalyzes phosphorylation of phosphatidylinositol lipids at the plasma membrane to generate second messengers like PIP₃ that activate downstream effectors including AKT. This pathway regulates essential cellular processes such as growth factor-mediated signal transduction, cell proliferation, survival, migration, and metabolism. The gene encoding p110α is PIK3CA, which is frequently mutated in various cancers—making it a major therapeutic target for small-molecule kinase inhibitors currently used or investigated for cancer treatment.[1][2][4][5]

Other names

PI3K p110αPIK3CA (gene name)Class IA PI3K catalytic subunit alpha

Drugs targeting this molecule typically act as ATP competitive inhibitors of the kinase domain, blocking the conversion of phosphatidylinositol substrates and downstream signaling through AKT and related pathways. This results in inhibition of cell growth, proliferation, and survival signals—especially relevant in cancer therapy where PIK3CA is mutated or overactive.[5]