Fatty acid translocase (FAT/CD36) in large yellow croaker (Larimichthys crocea): Molecular cloning, characterization and the response to dietary fatty acids

Fatty acid translocase (FAT/CD36) has been identified as a specific receptor of long-chain fatty acid and plays a crucial role in the homeostasis of lipid metabolism. However, little is known about the molecular function of CD36 in fish, especially in marine fish. In the present study, the cd36 gene in large yellow croaker (Larimichthys crocea) was cloned and characterized. The full-length cDNA of cd36 was 1989 bp, including an open reading frame of 1413 bp encoding 470 amino acids (GenBank Acc. No. MT246662). Sequence and subcellular locali-zation analysis revealed that cd36 possessed typic features of glycoprotein localized on the plasma membrane. Tissue distribution results in large yellow croaker showed that the gene expression of cd36 was the highest in the intestine and the lowest in the head kidney. The gene expression of cd36 in the liver of large yellow croaker fed the diet with soybean oil was significantly higher as compared with fish oil or linseed oil diets. Correspondingly, the treatment of linoleic acid (LA) up-regulated the expression of the CD36 gene and protein in primary he-patocytes of large yellow croaker. Moreover, results of dual-luciferase reporter assays showed that peroxisome proliferator-activated receptor alpha (PPAR alpha), peroxisome proliferator-activated receptor gamma (PPAR gamma) and retinoid X receptor alpha (RXR alpha) could significantly up-regulate the promoter activity of cd36, and the expression of ppar alpha and ppar gamma had the same change trend as cd36 expression in response to dietary fatty acids in vivo and in vitro. In conclusion, results of this study suggest that the expression of large yellow croaker cd36 may be regulated by dietary fatty acids via regulation of the expression of PPAR alpha and PPAR gamma. The acquisition of fish CD36 regulation mechanism in the present study will play the foundation for alleviating abnormal lipid deposition by nutritional regulation in aquaculture.