A combination of upstream and proximal elements is required for efficient expression of the mouse renin promoter in cultured cells.
Renin, a key enzyme controlling blood pressure, is produced mainly in the kidney. To identify the transcriptional regulatory elements of the mouse Ren-1c gene, the promoter regions were fused to the CAT reporter gene and transfected into embryonic kidney-derived 293 cells and four extrarenal cell lines, HeLa, HepG2, HT1080 and NIH3T3 cells. Transient transfection assay showed that sequences from -365 to +16 of the renin gene could direct transcription of the CAT hybrid gene only in 293 cells. Deletion analysis identified two transcriptionally active regions; the renin upstream-promoter element (RU-1 element; position -224 to -138) and the renin proximal-promoter element (RP-2 element; position -75 to -47). Although the RU-1 element functioned as an activator, depending on its orientation, it failed to trans-activate the renin promoter when the RP-2 element was deleted. By contrast, the proximal element alone exhibited a weak trans-activator property. Gel shift assay identified RU-1 element-binding factors in both 293 and HeLa cells, whereas 293 cell-dominant factors were shown to bind only to RP-2 element. Therefore, both RU-1 and RP-2 elements were found to be necessary for efficient CAT expression from the renin promoter in 293 cells, suggesting that activation of the Ren-1c promoter requires combined action between cell type-dominant and ubiquitous nuclear factors.
Tamura
K
K
Institute of Applied Biochemistry, University of Tsukuba, Japan.
Tanimoto
K
K
Murakami
K
K
Fukamizu
A
A
D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D012083:Renin / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D012083:Renin