Transcription Factor Sp1 Is Essential for the Regulation of the Porcine Caveolin-1 Gene

Caveolin-1 (CAV-1) is a key structural component of caveolae that regulates cholesterol. Employing transgenic techniques to regulate the cholesterol content of pork through CAV-1 is hindered by our lack of knowledge about its regulation. To investigate the regulatory mechanism of porcine CAV-1, a DNA segment containing the 5'-flanking region of CAV-1 was isolated from porcine genomic DNA and sequenced. The luciferase reporter assay detected five cis-acting elements for efficient expression of the CAV-1 gene at the region spanning nucleotides -213 to -20 with serially deleted 50-flanking sequences and site-directed mutants, -123 to -114 was the core promoter. The electrophoretic mobility shift assay demonstrated potential binding of Sp1 protein to this core promoter. The purpose of this study is to systematically elucidate the transcriptional regulation mechanism of porcine CAV-1 and to contribute to the investigation of the interaction between CAV-1 and cholesterol.