| abstract |
The present invention relates to the discovery, identification and characterization of nucleotides that encode the G protein regulated phosphatidylinositol-3' kinase, a heterodimeric enzyme which produces the intracellular messenger phosphatidylinositol (3, 4,5)-triphosphate in response to activation of trimeric G protein-linked receptors. This novel protein, comprised of a catalytic subunit, p120, and a regulatory subunit, p101, is found in cells of hematopoietic origin and is involved in immune system responses which cause inflammation. The presence of p101 subunit is largely responsible of the dramatic stimulation of kinase activity in the presence of activated trimeric G proteins. The invention encompasses p101 and p120 nucleotides, host cells expression systems, p101 and p120 proteins, fusion proteins, polypeptides and peptides, antibodies to these proteins, transgenic animals that express a p101 or p120 transgene, or recombinant knock-out cells and animals that do not express the p101 or p120 genes, antagonists and agonists of the enzyme, and other compounds that modulate p101 or p120 gene expression or enzyme activity that can be used for diagnosis, drug screening , clinical trial monitoring, and/or treatment of inflammatory disorders. |