Promoter activity of human renin 5'-flanking DNA sequences is activated by the pituitary-specific transcription factor Pit-1.
Although the renal juxtaglomerular cell is the source of circulating renin, the renin gene is also expressed at a number of extrarenal sites including lactotrope cells of human and ovine pituitaries. In the present study, we demonstrate that GC cells, a pituitary lactotrope precursor cell line, efficiently express transiently transfected hybrid genes containing human renin 5'-flanking DNA sequences -148/+11. Gel mobility shift competition analyses show that a highly conserved sequence in human and rodent renin 5'-flanking DNAs (human coordinates: -80/-58) binds a nuclear factor from GC cells, most likely the pituitary-specific factor Pit-1. Deletional and mutational analyses demonstrate that this site is a major determinant of renin promoter activity in GC cells. Transfection of a Pit-1 expression construct into HeLa cells, where activity of the human renin promoter is low, stimulates expression of cotransfected renin-luciferase constructs. Moreover, activation of the human renin promoter by co-expression of Pit-1 is dependent on an intact Pit-1 site. Taken together, these data strongly suggest that Pit-1 activates pituitary renin gene expression. This finding raises the possibility that member(s) of the POU family of transcription factors, of which Pit-1 is an archetypal member, may direct renin expression in other tissues, including the kidney.
Sun
J
J
Cardiovascular Center, Cornell University Medical College, New York, New York 10021.
Oddoux
C
C
Lazarus
A
A
Gilbert
M T
MT
Catanzaro
D F
DF
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D016384:Consensus Sequence; D004247:DNA / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010902:Pituitary Gland / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051381:Rats; D012083:Renin / Q000235:genetics*; D050817:Transcription Factor Pit-1; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014162:Transfection
D004247:DNA; D004268:DNA-Binding Proteins; D008156:Luciferases; D012083:Renin; D050817:Transcription Factor Pit-1; D014157:Transcription Factors; C494187:POU1F1 protein, human; C494185:Pou1f1 protein, mouse; C494186:Pou1f1 protein, rat