Molecular cloning, expression, and sequence analysis of GPRC6A, a novel family C G-protein-coupled receptor

TY - JOUR

T1 - Molecular cloning, expression, and sequence analysis of GPRC6A, a novel family C G-protein-coupled receptor

AU - Wellendorph, Petrine

AU - Bräuner-Osborne, Hans

PY - 2004/6/23

Y1 - 2004/6/23

N2 - By similarity searching of the human genome sequence using known family C G-protein-coupled receptors (GPCRs) as query sequences, we have identified a putative novel human gene product of unknown function (located on chromosome band 6q22.31). The transcript, entitled GPRC6A (isoform 1), was cloned from a human kidney cDNA (DNA complementary to RNA) library and shown to encode a protein of 926 amino acids (aa). Protein sequence analysis revealed the presence of a seven-transmembrane (7TM) domain and an unusually long amino-terminal domain (ATD) of 590 amino acids. These traits, along with a significant homology to the human calcium-sensing receptor (CaR, 34% aa sequence identity), the taste receptor 1 (T1R1, 28%), and the metabotropic glutamate receptor 1 (mGluR1, 24%), places GPRC6A in family C of the GPCRs. Interestingly, GPRC6A bears the highest resemblance with an odorant goldfish 5.24 receptor (45%) which suggests that GPRC6A is the human orthologue of this receptor. GPRC6A is widely expressed in brain and peripheral tissues with highest levels in kidney, skeletal muscle, testis, and leucocytes. All three isoforms are expressed in mammalian cells, but are poorly expressed on the cell surface. In this work, we report the existence of two additional GPRC6A isoforms (2 and 3) carrying in-frame deletions in the ATD. Except for the kidney, where isoforms 1 and 2 appear equally expressed, isoforms 2 and 3 are generally less abundant than isoform 1. Analysis of the intron-exon composition of the GPRC6A gene confirms that isoforms 2 and 3 are naturally occurring splice variants.

AB - By similarity searching of the human genome sequence using known family C G-protein-coupled receptors (GPCRs) as query sequences, we have identified a putative novel human gene product of unknown function (located on chromosome band 6q22.31). The transcript, entitled GPRC6A (isoform 1), was cloned from a human kidney cDNA (DNA complementary to RNA) library and shown to encode a protein of 926 amino acids (aa). Protein sequence analysis revealed the presence of a seven-transmembrane (7TM) domain and an unusually long amino-terminal domain (ATD) of 590 amino acids. These traits, along with a significant homology to the human calcium-sensing receptor (CaR, 34% aa sequence identity), the taste receptor 1 (T1R1, 28%), and the metabotropic glutamate receptor 1 (mGluR1, 24%), places GPRC6A in family C of the GPCRs. Interestingly, GPRC6A bears the highest resemblance with an odorant goldfish 5.24 receptor (45%) which suggests that GPRC6A is the human orthologue of this receptor. GPRC6A is widely expressed in brain and peripheral tissues with highest levels in kidney, skeletal muscle, testis, and leucocytes. All three isoforms are expressed in mammalian cells, but are poorly expressed on the cell surface. In this work, we report the existence of two additional GPRC6A isoforms (2 and 3) carrying in-frame deletions in the ATD. Except for the kidney, where isoforms 1 and 2 appear equally expressed, isoforms 2 and 3 are generally less abundant than isoform 1. Analysis of the intron-exon composition of the GPRC6A gene confirms that isoforms 2 and 3 are naturally occurring splice variants.

KW - Alternative Splicing

KW - Amino Acid Sequence

KW - Base Sequence

KW - Cell Line

KW - Cloning, Molecular

KW - DNA, Complementary

KW - Exons

KW - Female

KW - Gene Expression Profiling

KW - Genes

KW - Humans

KW - Introns

KW - Male

KW - Molecular Sequence Data

KW - Phylogeny

KW - Protein Isoforms

KW - RNA, Messenger

KW - Receptors, G-Protein-Coupled

KW - Sequence Alignment

KW - Sequence Analysis, DNA

KW - Sequence Homology, Amino Acid

U2 - 10.1016/j.gene.2004.03.003

DO - 10.1016/j.gene.2004.03.003

M3 - Journal article

C2 - 15194188

SN - 0378-1119

VL - 335

SP - 37

EP - 46

JO - Gene

JF - Gene

ER -