UNIPROT #

O00329

PROTEIN NAME

PI 3 Kinase p110 delta

SYNONYMS

5-bisphosphate 3-kinase 110 kDa catalytic subunit delta antibody; 5-bisphosphate 3-kinase catalytic subunit delta isoform antibody; APDS antibody; GRB1 antibody; IMD14 antibody; p110d antibody; p110delta antibody; p110dp85a antibody; p85-ALPHA antibody; Phosphatidylinositol 3 kinase catalytic delta polypeptide antibody; Phosphatidylinositol 4 5 bisphosphate 3 kinase catalytic subunit delta isoform antibody; Phosphatidylinositol 4,5 bisphosphate 3 kinase 110 kDa catalytic subunit delta antibody; Phosphatidylinositol 4,5 bisphosphate 3 kinase, catalytic subunit delta antibody; Phosphatidylinositol 45 bisphosphate 3 kinase catalytic subunit delta isoform antibody; Phosphatidylinositol-4 antibody; Phosphoinositide 3 kinase B antibody; Phosphoinositide 3 kinase C antibody; Phosphoinositide 3 kinase catalytic delta polypeptide antibody; Phosphoinositide 3 kinase, catalytic, delta polypeptide variant p37delta antibody; PI3 kinase p110 subunit delta antibody; PI3-kinase subunit delta antibody; PI3K antibody; PI3K-delta antibody; PI3Kdelta antibody; Pik3cd antibody; PIK3R1 antibody; PK3CD antibody; PK3CD_HUMAN antibody; PtdIns 3 kinase p110 antibody; PtdIns 3 kinase subunit p110 delta antibody; PtdIns-3-kinase subunit delta antibody; PtdIns-3-kinase subunit p110-delta antibody

SEQUENCE SIMILARITIES

Belongs to the PI3/PI4-kinase family.

TISSUE SPECIFICITY

Isoform 2 is expressed in normal thymus, lung and spleen tissues, and is detected at low levels in normal lysates from colon and ovarian biopsies, at elevated levels in lysates from colorectal tumors and is abundantly expressed in some ovarian tumors (at protein level). Both isoform 1 and isoform 2 are widely expressed. Isoform 1 is expressed predominantly in leukocytes.

POST-TRANSLATIONAL MODIFICATION

Autophosphorylation on Ser-1039 results in the almost complete inactivation of the lipid kinase activity.

SUBCELLULAR LOCATION

Cytoplasm.

FUNCTION

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 (p85α and p85β), each possessing one SH3 and two SH2 domains. Various p110 forms have been identified. p110α and p110β interact with p85α, and p110α has also been shown to interact with p85β in vitro. It has been shown to bind p85α and β, but it apparently does not phosphorylate these subunits. p110δ has the capacity to autophosphorylate and results in the nearly complete inactivation of the lipid kinase activity. Interestingly, p110γ does not interact with the p85 subunits and has been shown to be activated by α and βγ heterotrimeric G proteins. Two p110δ 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.