PIK3CD Antibody / p110delta

Phosphatidylinositol 3-kinase (PI 3-kinase) is composed of p85 and p110 subunits. p85 lacks PI 3-kinase activity and acts as an adapter, coupling p110 to activated protein tyrosine kinase. Two forms of p85 have been described (p85a and p85b), each possessing one SH3 and two SH2 domains. Various p110 forms have been identified. p110a and p110b interact with p85a, and p110a has also been shown to interact with p85b in vitro. It has been shown to bind p85a and b, but it apparently does not phosphorylate these subunits. p110d has the capacity to autophosphorylate and results in the nearly complete inactivation of the lipid kinase activity. Interestingly, p110g does not interact with the p85 subunits and has been shown to be activated by a and bg heterotrimeric G proteins. Two p110d isoforms have been identified and are widely expressed. Isoform 1 is expressed predominantly in leukocytes while isoform 2 is expressed in normal thymus, lung and spleen tissues.