Core promoter identification and transcriptional regulation of porcine <i>ACSL3</i> gene

Intramuscular fat (IMF) content is an important factor that affects the edible and processing quality of pork. Studying the transcriptional regulation mechanisms of genes affecting intramuscular fat deposition can provide theoretical support for genetic improvement in pigs. Long-chain fatty acyl-CoA synthase 3 (<i>ACSL3</i>), as a key enzyme in the process of lipid synthesis in mammals. However, no information about the core promoter of the <i>ACSL3</i> gene and its transcriptional regulation has been reported so far. In this experiment, we successfully cloned 3112 bp of the porcine <i>ACSL3</i> gene promoter region. In order to find out the core promoter of the <i>ACSL3</i> gene. The results indicated that the core promoter region of the <i>ACSL3</i> gene is located from -111 bp to -59 bp upstream of the transcription initiation site (TSS). To identify the interaction between SP1 and the <i>ACSL3</i> gene promoter, we mutated the predicted binding sites of <i>ACSL3</i> gene promoter. The results showed that the activity of the promoter was decreased by site-specific mutagenesis of the SP1 transcription factor binding site, while overexpression of SP1 increased the expression of the <i>ACSL3</i> gene. In summary, our study identified a core promoter region of the porcine <i>ACSL3</i> gene, and the SP1 binding site is responsible for the promoter activity.