Molecular cloning, characterization, tissue expression and nutritional regulation of O-GlcNAc transferase gene in hybrid grouper (Epinephelus fuscoguttatus female x E-lanceolatus male)

摘要

O-GlcNAc transferase gene (OGT) was considered as the sole rate-limiting enzyme in the O-GlcNAc modification. In the present study, the OGT gene of hybrid grouper (Epinephelus fuscoguttatus female x E. lanceolatus o) was cloned and characterized, and its expression in response to dietary carbohydrate level and acute glucose treatment was investigated. The full-length of OGT (GenBank accession no. ) was 4,063bp, including a 302bp 5'untranslated terminal region (UTR), a 3,165bp coding region that encoded 1,054 amino acids residues and a 596bp 3' UTR. The highly conservation of OGT gene between fish and mammals was also observed through multiple sequences alignment and phylogenetic analysis. O-GlcNAc transferase gene was ubiquitously expressed in all detected tissues with highest expressions in brain and liver, to a lesser degree, in eye, heart, kidney and intestine. The increasing dietary carbohydrate from 8.02% to 16.08% had no significant effect on the mRNA expression of OGT. However, the expression of OGT was slightly elevated at 6hr post-glucose injection, and the elevation became significant at 24hr time-point. These data may enhance our understanding on the nutritional regulation of OGT and O-GlcNAc modification in fish species.