Identification of an EDG7 variant, HOFNH30, a G-protein-coupled receptor for lysophosphatidic acid.

We have identified a cDNA, designated HOFNH30, which encodes a 354 amino acid G-protein-coupled receptor (GPCR). This receptor has 96% amino acid identity to the Jurkat-T cell-derived EDG7 and could be a splice variant. RT-PCR analysis demonstrated that HOFNH30 mRNA is expressed in placenta whereas EDG7 mRNA shows highest expression in prostate. The HOFNH30 gene is localized to human chromosome 1p22. 3-1p31.1. When HOFNH30 was expressed in RBL-2H3 cells, LPA and phosphatidic acid (PA) induced a calcium mobilization response with EC(50) values of 13 nM and 3 microM, respectively. LPA also induced phosphorylation of mitogen-activated protein kinase (p42(MAPK) and p44(MAPK)) in HOFNH30-transfected but not vector-transfected RBL-2H3 cells. In the present study, we have identified a novel variant from the EDG receptor family, a GPCR for which LPA is a high-affinity endogenous ligand.