Regulation of preprosomatostatin 1 (PSS1) gene expression by 17β-estradiol and identification of the PSS1 promoter region in orange-spotted grouper (Epinephelus coioides)

In the present paper the effects of 17β-estradiol on the expression of the preprosomatostatin 1 (PSS1) in the orange-spotted grouper hypothalamus and ovary were investigated. Results from in vivo of intraperitoneal injection and in vitro static cultures showed that estradiol increased the mRNA expression of PSS1 gene in both hypothalamus and ovary. To investigate the molecular basis of the estrogen regulation on PSS1 gene expression, we cloned the upstream region of 848 bp from the translation initiation codon of the grouper PSS1 gene. The TATA-box and putative transcription factor binding sites were identified using computer analysis. Transient transfections with promoter-luciferase reporter constructs together with hER expression vector were carried out in MCF-7 cell line. The results suggest that the region from −848 to −373 bp, containing five putative ERE half sites, may contribute to the promoter activity induced by estradiol. These results represent the first demonstration at the molecular level of the regulation of PSS1 gene by 17β-estradiol in fish.