title: Identification of a DNA-binding site for the transcription factor GC2 in the promoter region of the p12 gene and repression of its positive activity by upstream negative regulatory elements.
abstract: Mouse secretory protease inhibitor p12 is significantly transcribed by the cells from the seminal vesicle, the coagulating gland, the ventral prostate, and to a lesser level by the pancreas. It is otherwise undetectable in every other tissue examined. To study the molecular mechanisms involved in this model of cell-specific control of gene expression, we cloned fragments containing various lengths of the p12 promoter upstream of the CAT reporter gene. We demonstrated that p12 sequences from +34 to -108 relative to the CAP site can confer a constitutive level of CAT expression following transient transfection in non-prostatic CV1 and GH4C1 cells. We identified within this minimal p12 promoter the cis-acting sequences needed to direct such a significant level of CAT expression. A DNA-binding site (p12.A) highly homologous to the rat growth hormone (rGH) sequence recognized by the trans-acting factor GC2 was identified between the TATA- and the double CAAT-box sequences from the p12 promoter. Using competition and mutation analysis, we provide evidence that the positively acting p12.A-binding protein is likely to be the rGH GC2 transcription factor, suggesting that the same, or a very similar factor, regulates expression of both rGH and p12 genes. By further analysis of the p12 5'-flanking sequences, we demonstrated that plasmids including sequences from -109 to -843 can strongly repress the level of transcription directed by this minimal p12 promoter, providing evidence for the presence of cis-acting negative regulatory elements critical for the establishment of p12 gene extinction in non-prostatic cells.
authors: Unité d'Endocrinologie Moléculaire, Centre de Recherche du Centre Hospitalier de l'Université Laval, Québec, Canada.
authors: S L
authors: SL
authors: Guérin
authors: F
authors: F
authors: Pothier
authors: S
authors: S
authors: Robidoux
authors: P
authors: P
authors: Gosselin
authors: M G
authors: MG
authors: Parker
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011480:Protease Inhibitors; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection
chemical_list: D004268:DNA-Binding Proteins; D011480:Protease Inhibitors; D016329:Sp1 Transcription Factor; D014157:Transcription Factors