MOLECULAR-CLONING, CDNA SEQUENCE, AND CHROMOSOMAL LOCALIZATION OF THEHUMAN PHOSPHATIDYLINOSITOL 3-KINASE P110-ALPHA (PIK3CA) GENE

Phosphatidylinositol (PI) 3-kinase is a heterodimeric enzyme comprisin g a 110-kDa catalytic subunit and an 85-kDa regulatory subunit that bi nds to tyrosine phosphopeptide sites linked directly or indirectly to receptors serving diverse signal functions. Knowledge of the structure and function of PI 3-kinase was greatly advanced by the purification, cDNA cloning, and subsequent expression of the bovine enzyme. Here th e cloning of the cDNA for the human p110 alpha subunit of PI3-kinase ( PIK3CA), encoding a protein 99% identical to the bovine p110, and of i ts gene in YAC is described. The chromosomal localization of the gene for PIK3CA is shown to be at 3q21-qter as determined using somatic cel l hybrids. In situ hybridization performed using Alu-PCR from the YAC DNA located the gene in 3q26.3. (C) 1994 Academic Press, Inc.