IDENTIFICATION AND CDNA CLONING OF A NOVEL MAMMALIAN C2 DOMAIN-CONTAINING PHOSPHOINOSITIDE 3-KINASE, HSC2-PI3K

Phosphoinositide (PI) S-kinases have been shown to have critical roles in signal transduction, cell transformation and intracellular protein trafficking. Reverse-transcription polymerase chain reaction methods, using degenerate primers derived from the lipid kinase consensus regi on, were utilised to identify PI S-kinases in the normal human breast. Here we report the cDNA cloning of a novel human PI 3-kinase isoform, HsC2-PI3K. This PI 3-kinase is most closely related to the recently d escribed C2 domain-containing family of PI 3-kinases which includes Dr osophila PI3K_68D/cpk and murine cpk-m/p170. Sequence analysis suggest s that HsC2-PI3K is a second distinct mammalian member of the C2 domai n-containing PI 3-kinase family. Northern blot analysis of human tissu es indicates that HsC2-PI3K is widely expressed. Fluorescence in situ hybridisation has mapped HsC2-PI3K to chromosome 1q32. (C) 1997 Academ ic Press.