Deletional analysis of the human renin promoter: transcriptional activation by the SV40 enhancer enables identification of promoter regulatory elements in non-renin-expressing cells.

Identification of regulatory elements in the human renin gene promoter has been hindered by the lack of suitable renin-expressing cell lines. In this paper, the SV40 viral enhancer is coupled to a human renin promoter/chloramphenicol acetyltransferase (CAT) reporter gene construct, to determine whether promoter regulatory elements can be identified in the context of enhanced transcription in the normally non-renin-expressing HeLa cell line. The present results indicate that the SV40 enhancer can overcome tissue-specificity of the human renin promoter, and confer correctly initiated transcriptional activity to HeLa cells. Analysis of a series of 5'-end deletions of the human renin promoter linked to the CAT gene and SV40 enhancer identified negative regulatory elements between positions-275 and -225, and between-142 and -102 of the human renin promoter, as well as a positive regulatory element between -225 and -142. Thus, studies of renin promoter regulatory elements need not be limited to renin-expressing cells, but can be performed in non-renin-expressing cells with the addition of an enhancer. This strategy can be generally applicable to the study of tissue-specific gene regulation in cases where there are no specific cell lines available.