Title | Identification of functional cis-acting elements within the rat liver S14 promoter. |
Publication Type | Journal Article |
Year of Publication | 1991 |
Authors | MacDougald, OA, Jump, DB |
Journal | Biochem J |
Volume | 280 ( Pt 3) |
Pagination | 761-7 |
Date Published | 1991 Dec 15 |
ISSN | 0264-6021 |
Keywords | Animals, Base Sequence, Cell Nucleus, Deoxyribonuclease I, DNA Mutational Analysis, DNA-Binding Proteins, Gene Expression Regulation, Liver, Male, Molecular Sequence Data, Organ Specificity, Promoter Regions, Genetic, Rats, Rats, Inbred Strains, Ribosomal Proteins, Transcription, Genetic |
Abstract | The structure of DNAase I hypersensitive site 1 (Hss-1), located adjacent to the 5' end of the rat liver S14 gene, is regulated by tissue-specific factors, and its formation correlates with the transcriptional activation of the S14 gene. We propose that tissue-specific trans-acting factors interacting with key cis-linked elements within this site function in the initiation of S14 gene transcription. To examine this hypothesis we used DNAase I footprint, gel shift and in vitro transcriptional analyses to identify cis-linked elements that function in the control of S14 gene transcription. Binding of rat liver nuclear proteins to the S14 promoter (from -8 to -464 bp) produced four DNAase I footprints (designated A-D). Gel shift studies showed that DNA-protein binding was tissue- and sequence-specific, differentially heat-sensitive, and abolished by proteinase K. The function of the four cis-acting elements was assessed by using an in vitro transcription initiation assay in which the S14 promoter was fused to a reporter gene (G-free cassette). Deletion studies showed that nuclear factors binding to regions A (-48 to -63 bp), B (-88 to -113 bp) and D (-286 to -310 bp) enhanced the rate of initiation of transcription, while proteins binding to region C (-227 to -244 bp) suppressed the rate of initiation of transcription. Based on oligonucleotide competition studies, we suggest that hepatic NF-1 (or a related protein) binding to the A region enhances the rate of initiation of S14 gene transcription. Since trans-acting factors interacting with regions B and D are found in liver but not in spleen or kidney, we suggest that the proteins interacting with these regions may be involved in the tissue-specific augmentation of S14 gene transcription. |
Alternate Journal | Biochem. J. |
PubMed ID | 1764039 |
PubMed Central ID | PMC1130519 |
Grant List | R01 DK043220 / DK / NIDDK NIH HHS / United States |