Cloning and characterization of the proximal promoter of the human selenoprotein H gene

Selenium plays important roles in cancer chemoprevention, neurobiology, thyroid and muscle metabolisms, immune function and many other aspects of health. There is increasing evidence that the biological functions of selenium are mediated by selenoproteins, therefore it is important to identify, characterize and determine their functions. Twenty‐eight human selenoproteins containing selenium as selenocysteine have been identified but detailed elucidation of their functions is still ongoing. Selenoprotein H (SelH) is one of those proteins, whose function is yet to be determined. Its expression may be an important component of the cellular defense system against oxidative stress. This is supported by the fact that neuronal cell lines over expressing SelH showed more resistance to UV induced cell death than normal cell line. Understanding influences on transcriptional regulation will aid in gaining additional cellular roles of selenoproteins. In this study we investigate the proximal promoter of SelH gene by computational analysis and examine the SelH promoter activity in 6 cell lines. The SelH promoter was 4–10 fold more active than the SV40 promoter. To understand transcriptional regulation of the SelH gene the MRE and NFkB sites were tested using mutational, deletion or CHIP analyses. Additionally, we tested the influence of methylation and selenium concentrations on SelH gene expression.