Molecular cloning, tissue distribution and gene expression in response to nutritional regulation of sterol regulatory element binding protein-1 from the swimming crab Portunus trituberculatus (Miers, 1876) (Decapoda, Portunidae)

Abstract

Abstract The sterol regulatory element-binding proteins (SREBPs) are a family of transcription factors known to activate the transcription of genes encoding key lipogenic enzymes. The present study reports on the molecular cloning, tissue expression and nutritional regulation of SREBP-1 from the swimming crab Portunus trituberculatus (Miers, 1876). The SREBP-1 full-length cDNA was 3785 bp, encoding a polypeptide of 1039 amino acids. Quantitative PCR analysis revealed that SREBP-1 expression was detected in various tissues, and the significantly higher expression levels were found in eyestalk and hepatopancreas compared with other tested tissues. Additionally, the effects of dietary iron on expression of SREBP-1 were investigated, and the results indicated that SREBP-1 expressions were down-regulated by crabs fed diets containing 218.9 and 373.9 mg/kg iron compared with that fed the basal diet (55.2 mg/kg). Suggesting that the relative expression level of SREBP-1 can be suppressed by dietary iron supplementation. These findings provide further insight into the regulatory capacity of SREBP-1 in the lipid anabolism of P. trituberculatus.