Abstract:

To explore the structure and function of G protein couple receptors in teleost, a new gene encoding G protein couple receptor were cloned and characterized from zebrafish Danio rerio, and designated as DrGPCR. The full-length cDNA sequence of DrGPCR was 2251 bp containing an 1170 bp of ORF and encoding 389 amino acid residues. SMATR analysis showed that DrGPCR contains seven transmembrane domains, suggesting that it was a membrane protein. BLAST analysis against non-redundant protein database indicated that DrGPCR exhibit high amino acid sequence identity to FMRFamide receptor of invertebrate and GPCR139 or GPCR142 of vertebrates. Moreover, 3D model of DrGPCR was highly similar to that of GPR139 from Homo sapiens. Sequence analysis and structural feature indicated that DrGPCR is a member of GPCR family. Phylogenetic analysis with neighbor joining method indicated that DrGPCR belongs to rhodopsin subgroup. The expression of DrGPCR was examined in various tissues with semi-quantitative RT-PCR. The highest expression of DrGPCR was observed in brain and hepatopancreas. The results all together suggested that DrGPCR might play a role in neuromodulation or immunity.