Molecular cloning and gene expression of acc2 from grass carp (Ctenopharyngodon idella) and the regulation of glucose metabolism by ACCs inhibitor.

BACKGROUND: Acetyl-CoA carboxylase (ACC) catalyzes the carboxylation of acetyl-CoA to malonyl-CoA. Malonyl-CoA, which plays a key role in regulating glucose and lipid metabolism, is not only a substrate for fatty acid synthesis but also an inhibitor of the oxidation pathway. ACC exists as two isoenzymes that are encoded by two different genes. ACC1 in grass carp (Ctenopharyngodon idellus) has been cloned and sequenced. However, studies on the cloning, tissue distribution, and function of ACC2 in grass carp were still rare.

METHODS AND RESULTS: The full-length cDNA of acc2 was 8537 bp with a 7146 bp open reading frame encoding 2381 amino acids. ACC2 had a calculated molecular weight of 268.209 kDa and an isoelectric point of 5.85. ACC2 of the grass carp shared the closest relationship with that of the common carp (Sinocyclocheilus grahami). The expressions of acc1 and acc2 mRNA were detected in all examined tissues.  The expression level of acc1 was high in the brain and fat but absent in the midgut and hindgut. The expression level of acc2 in the kidney was significantly higher than in other tissues, followed by the heart, brain, muscle, and spleen. ACCs inhibitor significantly reduced the levels of glucose, malonyl-CoA, and triglyceride in hepatocytes.

CONCLUSIONS: This study showed that the function of ACC2 was evolutionarily conserved from fish to mammals. ACCs inhibitor inhibited the biological activity of ACCs, and reduced fat accumulation in grass carp.