Phospholipase C-148: Chromosomal Location and Deletion Mapping of Functional Domains

Abstract

The binding of various agonists to their specific cell-surface receptors rapidly induces the formation of two second-messenger molecules derived from phosphatidylinositol 4,5-bisphosphate: diacylglycerol and inositol 1,4,5-trisphosphate (Berridge 1984). The production of these second-messenger molecules is mediated by activated phosphatidylinositol-specific phospholipase C (PLC) enzymes (Berridge 1987). Evidence has accumulated that would suggest the existence of a number of immunologically distinct enzymes with phosphatidylinositol-specific PLC activities (Hoffman and Majerus 1982; Bennett and Crooke 1987; Katan and Parker 1987; Rebecchi and Rosen 1987; Ryu et al. 1987a,b). We have recently purified, cloned, and expressed one of these PLC subtypes, which we refer to as PLC-148 (Stahl et al. 1988). PLC-148 mRNA is expressed in most cell types and is present as a single-copy gene. A comparison of the PLC-148 amino acid sequence with those present in the National Biomedical Research Foundation (NBRF) data base revealed significant homology between PLC-148 and the nonreceptor protein...