Characterization of the fatty acid binding protein 3 (FABP3) promoter and its transcriptional regulation by cAMP response element binding protein 1 (CREB1) in goat mammary epithelial cells Item

In this study, the <i>FABP3</i> 5' flanking region was amplified from goat genomic DNA. Luciferase reporter vectors containing promoter fragments of five different lengths of the promoter fragment were constructed and transfected into dairy goat mammary epithelial cells. The region of the promoter located between -1801 and −166 bp upstream of the transcription start site (TSS) had the highest luciferase activity, and contained two cAMP response elements (CRE) located at -1632 bp and -189 bp. Interference with <i>CREB1</i> significantly downregulated <i>FABP3</i> promoter activity. In addition, <i>FABP3</i> promoter activity was significantly reduced after mutation of the CRE1 (-1632 bp) and CRE2 (-189 bp). Further analysis indicated that the CRE2 site was essential for the transcriptional activity induced by <i>CREB1</i>. These results demonstrated that CREB1 is involved in the transcriptional regulation of FABP3 via a direct mechanism in the goat mammary gland, thus providing a novel signaling pathway within fatty acid metabolism in ruminants.