Mouse phosphoinositide 3-Kinase p110α gene:: Cloning, structural organization, and localization to chromosome 3 band B

Phosphoinositide 3-Kinases (PI3-Kinases) are a family of dual specificity enzymes with a unique lipid kinase activity toward the D-3 position of the inositol ring of phosphoinositides and a less well characterized serine/threonine protein kinase activity. Class IA PI3-Kinases comprise a 110-120 kDa catalytic subunit (usually termed p110) and an 85 kDa or 50 to 55 kDa regulatory subunit (often called p85). cDNAs for three mammalian Class IA PI3-Kinase catalytic subunits designated p110 alpha; p110 beta, and p110 delta have been cloned from several species. A YAC clone for the human p110 alpha gene has also been cloned and mapped to chromosome 3q26.3. However, structural organization for any of the PI3-Kinase p110 alpha genes has not been reported. Here, we report the cloning, structural organization, and chromosomal localization of the mouse PI3-Kinase p110 alpha gene. The translated portion of the mouse p110 alpha gene is encoded by 19 exons that span at least 24 kb. Dual color fluorescence in situ hybridization (FISH) was performed to determine the chromosomal localization of the mouse PI3-Kinase p110 alpha gene. FISH results and DAPI banding demonstrated localization of the p110 alpha gene to band B on mouse chromosome 3, a region syntenic with human chromosome 3q26.3. (C) 1999 Academic Press.