title: Pharmacological characterization of relaxin-3/INSL7 receptors GPCR135 and GPCR142 from different mammalian species.
abstract: Relaxin-3 has recently been identified as a ligand for two structurally related G-protein-coupled receptors, human GPCR135 and GPCR142. This current study reports the characterization of mouse and rat GPCR135 as well as GPCR142 from mouse, monkey, cow, and pig at the molecular and pharmacological levels. Mouse and rat GPCR135 exhibit high homology (>85%) to the human GPCR135 and have very similar pharmacological properties to that of the human GPCR135. Human and mouse/rat relaxin-3 both bind to and activate mouse, rat, and human GPCR135 at high affinity with IC(50) or EC(50) values close to 0.5 nM. In contrast, the mouse GPCR142 is less well conserved (74% homology) with human GPCR142. The rat GPCR142 gene was found to be a pseudogene. We further cloned GPCR142 genes from monkey, cow, and pig and found that they are highly homologous (>84%) to human GPCR142. Pharmacological characterization of GPCR142 from different species demonstrated that relaxin-3 binds to GPCR142 from different species at high affinity (IC(50) < 5 nM). However, relaxin-3 does not stimulate a Ca(2+) response in cells coexpressing Galpha(16) and mouse GPCR142, whereas it does for cells expressing GPCR142 from other species tested. Our results suggest that GPCR142 may have a diminished role as a receptor for relaxin-3 in rodents, or perhaps GPCR142 functions as a receptor for another ligand in nonrodents. Boels and Schaller recently reported bradykinin as a ligand for GPCR142 (also known as GPR100). In this report, we demonstrate that bradykinin activates neither GPCR135 nor GPCR142, whereas relaxin-3 does.
authors.affiliation: Johnson & Johnson Pharmaceutical Research and Development, L.L.C., 3210 Merryfield Row, San Diego, CA 92121, USA.
authors.forename: Jingcai
authors.initials: J
authors.lastname: Chen
authors.forename: Chester
authors.initials: C
authors.lastname: Kuei
authors.forename: Steven W
authors.initials: SW
authors.lastname: Sutton
authors.forename: Pascal
authors.initials: P
authors.lastname: Bonaventure
authors.forename: Diane
authors.initials: D
authors.lastname: Nepomuceno
authors.forename: Elo
authors.initials: E
authors.lastname: Eriste
authors.forename: Rannar
authors.initials: R
authors.lastname: Sillard
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Lovenberg
authors.forename: Changlu
authors.initials: C
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001920:Bradykinin / Q000494:pharmacology; D016466:CHO Cells; D003001:Cloning, Molecular; D017124:Conserved Sequence; D006224:Cricetinae; D006801:Humans; D008024:Ligands; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D018000:Receptors, Peptide / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D012065:Relaxin / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014018:Tissue Distribution
chemical_list: D008024:Ligands; D009419:Nerve Tissue Proteins; C466742:RLN3 protein, rat; D012333:RNA, Messenger; C410092:RXFP3 protein, human; C577472:RXFP3 protein, rat; C480239:RXFP4 protein, human; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; D012065:Relaxin; D001920:Bradykinin