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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-9-18
pubmed:abstractText
To assess thyroid hormone receptor (TR)-mediated activation of transcription in yeast in the presence or absence of thyroid hormone (T3), we developed a co-expression system using a TR-beta 1 expression vector and a reporter plasmid containing a 16 base pair palindromic thyroid hormone response element (TRE) upstream from a proximal CYC1 promoter that was fused to the beta-galactosidase lac Z gene of Escherichia coli. Although TR-beta 1 functions as a repressor in most mammalian systems, using our system we observed a unique thyroid hormone-independent transcriptional response indicating that wild TR-beta 1 acted as a constitutive activator in yeast; the addition of 1 microM T3 induced a moderate but significant (p less than 0.01) 25-40% further increase in transcriptional activity. Using a series of rat TR-beta 1 mutant constructs, we found that deletion of domain D and portions of E completely eliminated transcriptional activity, whereas truncations of domain F and E permitted a partial (20-40%) response compared to wild TR-beta 1 in the presence or absence of T3. These observations indicate that TR-beta 1 functions as an activator in yeast and that domains D,E and F play important interactive roles in its hormone-independent gene activation with the D domain likely being the most essential. Furthermore, our results suggest that the different transcriptional property of TR-beta 1 in yeast compared to mammalian cells i.e. activator vs repressor function, is likely determined by transcriptional factor differences which are dependent upon cellular origin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
178
pubmed:geneSymbol
c-erb A
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1167-75
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:1651714-Amino Acid Sequence, pubmed-meshheading:1651714-Animals, pubmed-meshheading:1651714-Base Sequence, pubmed-meshheading:1651714-Escherichia coli, pubmed-meshheading:1651714-Gene Expression Regulation, Fungal, pubmed-meshheading:1651714-Genes, Bacterial, pubmed-meshheading:1651714-Genetic Vectors, pubmed-meshheading:1651714-Liver, pubmed-meshheading:1651714-Molecular Sequence Data, pubmed-meshheading:1651714-Oligonucleotide Probes, pubmed-meshheading:1651714-Promoter Regions, Genetic, pubmed-meshheading:1651714-Proto-Oncogene Proteins, pubmed-meshheading:1651714-Rats, pubmed-meshheading:1651714-Receptors, Thyroid Hormone, pubmed-meshheading:1651714-Restriction Mapping, pubmed-meshheading:1651714-Saccharomyces cerevisiae, pubmed-meshheading:1651714-Thyroid Hormones, pubmed-meshheading:1651714-Transcription, Genetic, pubmed-meshheading:1651714-Transcriptional Activation, pubmed-meshheading:1651714-beta-Galactosidase
pubmed:year
1991
pubmed:articleTitle
Rat liver c-erb A beta 1 thyroid hormone receptor is a constitutive activator in yeast (Saccharomyces cerevisiae): essential role of domains D,E and F in hormone-independent transcription.
pubmed:affiliation
Thyroid Research Laboratory, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't