Functional Analysis of Steroidogenic Factor 1 (sf-1) and 17α-Hydroxylase/Lyase (cyp17α) Promoters in Yellow Catfish Pelteobagrus fulvidraco

The present study was performed to clone and characterize the structures and functions of steroidogenic factor 1 (sf-1) and 17 alpha-hydroxylase/lyase (cyp17 alpha) promoters in yellow catfish Pelteobagrus fulvidraco, a widely distributed freshwater teleost. We successfully obtained 1981 and 2034 bp sequences of sf-1 and cyp17 alpha promoters, and predicted the putative binding sites of several transcription factors, such as Peroxisome proliferator-activated receptor alpha (PPAR alpha), Peroxisome proliferator-activated receptor gamma (PPAR gamma) and Signal transducer and activator of transcription 3 (STAT3), on sf-1 and cyp17 alpha promoter regions, respectively. Overexpression of PPAR gamma significantly increased the activities of sf-1 and cyp17 alpha promoters, but overexpression of PPAR alpha significantly decreased the promoter activities of sf-1 and cyp17 alpha. Overexpression of STAT3 reduced the activity of the sf-1 promoter but increased the activity of the cyp17 alpha promoter. The analysis of site-mutation and electrophoretic mobility shift assay suggested that the sf-1 promoter possessed the STAT3 binding site, but did not the PPAR alpha or PPAR gamma binding sites. In contrast, only the PPAR gamma site, not PPAR alpha or STAT3 sites, was functional with the cyp17 alpha promoter. Leptin significantly increased sf-1 promoter activity, but the mutation of STAT3 and PPAR gamma sites decreased leptin-induced activation of sf-1 promoter. Our findings offered the novel insights into the transcriptional regulation of sf-1 and cyp17 alpha and suggested leptin regulated sf-1 promoter activity through STAT3 site in yellow catfish.

Automated summary

This study focused on cloning and characterizing the promoters of sf-1 and cyp17 alpha in yellow catfish, unveiling potential binding sites for transcription factors like PPAR alpha, PPAR gamma, and STAT3. Overexpression of PPAR gamma enhanced promoter activity while PPAR alpha reduced it. STAT3 had contrasting effects on sf-1 and cyp17 alpha promoters.