Cloning and characterization of a new member of the G-protein coupled receptor EDG family

Recept Channels. 1995;3(4):255-62.


We report here the cloning of a new member of the endothelium differentiation gene (edg) subfamily of G-protein-coupled receptors. This novel cDNA sequence was cloned from the ovine pars tuberalis using a reverse transcriptase polymerase chain reaction (RT-PCR) amplification with degenerate primers homologous to the highly conserved II and VII transmembrane domains of the G-protein coupled receptor gene family. The PCR product was random primed with 32P and used as a probe to screen a size-selected cDNA ovine pars tuberalis library, which resulted in the isolation of a single clone of 2700 bp. This novel sequence was named edg-2, because its nucleic acid sequence was 55% homologous over 501nt overlap to an orphan sequence cloned from human endothelial cells, the endothelial differentiation gene, edg-1. The highest degree of aminoacid homology (42%) occurs in the seven putative transmembrane domains, particularly between the transmembrane domains III and VI (53% and 64%, respectively). The intervening hydrophilic domains are short and there are numerous putative phosphorylation sites for Ser/Thr-protein kinases in the second and third intracellular loop and in the COOH-terminal domain. Through Northern analysis of total RNA, low levels of at least four transcripts of 2.3, 2.5, 3.2 and 4 kb were found in sheep cerebral cortex and a 4.2 kb transcript was observed in NIH/3T3 fibroblasts. In addition, edg-2 transcripts (415 bp) were amplified by RT-PCR from pars tuberalis, cerebral blood vessels, hypothalamus, and retina. Serum stimulation of Chinese hamster ovary (CHO) cells expressing the edg-2 receptor resulted in increased cell proliferation, as measured by [3H]-thymidine incorporation. Edg-1 and edg-2 appear to be distinct genes that may encode protein products that bind the same or related ligand.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3T3 Cells
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • CHO Cells
  • Cells, Cultured
  • Cloning, Molecular
  • Cricetinae
  • DNA, Complementary
  • GTP-Binding Proteins / metabolism*
  • Humans
  • Mice
  • Molecular Sequence Data
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Cell Surface*
  • Receptors, G-Protein-Coupled*
  • Receptors, Lysophosphatidic Acid
  • Sequence Homology, Amino Acid
  • Sheep
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Tumor Cells, Cultured


  • DNA, Complementary
  • Nuclear Proteins
  • RNA, Messenger
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Receptors, Lysophosphatidic Acid
  • Transcription Factors
  • GTP-Binding Proteins

Associated data

  • GENBANK/U18405