PI3Kalpha, catalytic domain (IPR037704)

Short name: PI3Kalpha_dom

Overlapping homologous superfamilies

Domain relationships


This entry represents the catalytic domain of PI3Kalpha (also known as p110alpha), which is a Class IA phosphoinositide-3-kinase (PI3K) that that phosphorylates PtdIns (Phosphatidylinositol), PtdIns4P (Phosphatidylinositol 4-phosphate) and PtdIns(4,5)P2 (Phosphatidylinositol 4,5-bisphosphate) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3). PI3Kalpha plays an important role in insulin signaling [PMID: 16647110]. It also mediates cardiac growth induced by exercise training [PMID: 17202264]. Mutations in the PI3Kalpha gene have been linked to various cancers [PMID: 16627990].

PI3Ks can be divided into three main classes (I, II, and III), defined by their substrate specificity, regulation, and domain structure. Class I PI3Ks are the only enzymes capable of converting PtdIns(4,5)P2 to the critical second messenger PtdIns(3,4,5)P3. Class I enzymes are heterodimers and exist in multiple isoforms consisting of one catalytic subunit (p110alpha, beta, gamma or delta) and one of several regulatory subunits (p85alpha, beta or gamma). They are further classified into class IA (alpha, beta and delta) and IB (gamma). Class IA enzymes contain an N-terminal p85 binding domain, a Ras binding domain, a lipid binding C2 domain, a PI3K homology domain of unknown function, and a C-terminal ATP-binding cataytic domain. They associate with a regulatory subunit of the p85 family and are activated by tyrosine kinase receptors [PMID: 10580505].

GO terms

Biological Process

GO:0014065 phosphatidylinositol 3-kinase signaling

Molecular Function

GO:0035004 phosphatidylinositol 3-kinase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.