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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
7
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pubmed:dateCreated |
1989-11-6
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pubmed:abstractText |
Pituitary thyrotroph cells specialize in the synthesis of TSH, and thus represent a model to study cell-specific gene expression. We have used the murine TSH beta (mTSH beta) gene promoter and TSH-producing and nonproducing transplantable tumors derived from murine thyrotroph cells, referred to as TtT-97 and MGH 101A, respectively, to identify nuclear factors which selectively interact with the mTSH beta gene. DNase I protection analyses demonstrate that factors present in TtT-97 nuclear extracts bind with high affinity to five separate sites in the TSH beta promoter region, denoted as distal D1 (-253 to -227) and proximal, P1 (-76 to -68), P2 (-106 to -98), P3 (-126 to -112), and P4 (-142 to -131) footprints. By contrast, non-TSH beta expressing thyrotroph cell nuclear extracts and L-cell nonpituitary cell extracts did not appear to footprint the D1 site; whereas the nonpituitary nuclear extracts revealed minimal DNase I protection in the P1-P4 regions. These data show that the distal D1 site is thyrotroph specific and contains a 6 base pair direct repeat sequence (5'-AGATAT-3'). Factor occupancy of the D1 site is protein dependent, occurs rapidly (less than 15 sec), is destabilized by 170 mM KCl, and results in an associated DNase I hypersensitive region. A double-stranded oligonucleotide spanning the D1 footprint competes only the distal factor binding region. Transfection of plasmid constructs containing progressive 5'-deletions of the mTSH beta promoter linked to the reporter gene luciferase into primary TtT-97 cells demonstrate a marked decrease in activity between the regions -270 and -79, which contains the D1 region.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0888-8809
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
3
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1037-45
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2797001-Animals,
pubmed-meshheading:2797001-Binding, Competitive,
pubmed-meshheading:2797001-DNA-Binding Proteins,
pubmed-meshheading:2797001-Deoxyribonuclease I,
pubmed-meshheading:2797001-Electricity,
pubmed-meshheading:2797001-Mice,
pubmed-meshheading:2797001-Pituitary Gland, Anterior,
pubmed-meshheading:2797001-Pituitary Neoplasms,
pubmed-meshheading:2797001-Regulatory Sequences, Nucleic Acid,
pubmed-meshheading:2797001-Thyrotropin,
pubmed-meshheading:2797001-Transcription Factors,
pubmed-meshheading:2797001-Transfection,
pubmed-meshheading:2797001-Tumor Cells, Cultured
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pubmed:year |
1989
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pubmed:articleTitle |
Identification of thyrotroph-specific factors and cis-acting sequences of the murine thyrotropin beta subunit gene.
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pubmed:affiliation |
Department of Medicine, University of Colorado Health Sciences Center, Denver 80262.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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