Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD)

Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD), also known as p110δ, is a catalytic subunit of class I phosphoinositide 3-kinases (PI3Ks). It plays crucial roles in intracellular signaling pathways, especially within the immune system. PIK3CD encodes the p110δ protein, which forms part of the PI3K delta enzyme complex. This enzyme phosphorylates phosphatidylinositol (PI) and its derivatives to generate phosphatidylinositol (3,4,5)-trisphosphate (PIP3), a second messenger that activates downstream signaling cascades involved in cell growth, survival, proliferation, motility, and morphology. In immune cells—particularly B cells and T cells—p110δ is essential for cell development, proliferation, migration, differentiation, and function. Mutations in *PIK3CD* can lead to immunodeficiency disorders such as activated PI3K-delta syndrome type 1. Because of its central role in immune regulation, p110δ is a promising target for drugs that aim to prevent or treat inflammation, autoimmunity and transplant rejection.

Other names

p110δPI(4)P(2)-dependent kinaseClass IA PI kinase delta

PI3K-delta inhibitor