An Evolutionarily Conserved G-Protein Coupled Receptor Family, SREB, Expressed in the Central Nervous System

• Published in: Biochemical and biophysical research communications 2000-06, Vol.272 (2), p.576-582
• Main Authors: Matsumoto, Mitsuyuki, Saito, Tetsu, Takasaki, Jun, Kamohara, Masazumi, Sugimoto, Toru, Kobayashi, Masato, Tadokoro, Mina, Matsumoto, Shun-ichiro, Ohishi, Takahide, Furuichi, Kiyoshi
• Format: Article
• Language: English
• Subjects: amine-like receptor; Amino Acid Sequence; Animals; Biogenic Amines - metabolism; Brain - metabolism; central nervous system; CHO Cells; chromosome 3; chromosome 7; Chromosome Mapping; Chromosomes, Human - genetics; Cloning, Molecular; Conserved Sequence - genetics; Cricetinae; evolution; Expressed Sequence Tags; G-protein coupled receptor; Gene Expression Profiling; genital organs; Heterotrimeric GTP-Binding Proteins - metabolism; human chromosome locus; Humans; Introns - genetics; Ligands; Lod Score; Molecular Sequence Data; Multigene Family - genetics; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Open Reading Frames - genetics; Rats; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; RNA, Messenger - analysis; RNA, Messenger - genetics; Sequence Alignment; SREB; SREB1 gene; SREB2 gene; SREB3 gene; subfamily; zebrafish; Zebrafish - genetics
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.2000.2829

We report here a novel family of G-protein coupled receptor (GPCR) which is extraordinarily conserved among vertebrate species. This family, designated SREB (Super Conserved Receptor Expressed in Brain), consists of at least three members, termed SREB1, SREB2, and SREB3. SREB members share 52–63% amino acid identity with each other and show relatively high similarity to previously known amine amine GPCRs (approximately 25% identity). Amino acid sequence identity between human and rat orthologues is 97% for SREB1 and 99% for SREB3, while the SREB2 sequence is surprisingly completely identical between the species. Furthermore, amino acid sequence of zebrafish SREB2 and SREB3 are 94 and 78% identical to mammal orthologues. Northern blot analysis revealed that SREB members are predominantly expressed in the brain regions and genital organs. Radiation hybrid analysis localized SREB1, SREB2, and SREB3 genes to different human chromosomes, namely 3p21–p14, 7q31 and Xp11, respectively. The high sequence conservation and abundant expression in the central nervous system suggest the existence of undiscovered fundamental neuronal systems consisting of SREB family members and their endogenous ligand(s).