Linked Life Data

8702791

Source:http://linkedlifedata.com/resource/pubmed/id/8702791

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
1996-10-11
pubmed:abstractText
Tax protein of the human T-cell lymphotropic virus type 1 (HTLV-I) is critical for viral replication and is a potent transcriptional activator of viral and cellular polymerase II (pol II) genes. We report here that Tax is able to transactivate a classical pol III promoter, VA-I. In cotransfection experiments, Tax is shown to increase transcription of the VA-I promoter approximately 25-fold. Moreover, Tax is able to activate VA-I transcription when added exogenously to an in vitro transcription reaction. Using Tax affinity column chromatography, we demonstrate that Tax is able to deplete a HeLa cell extract for components required for transcription of VA-I. The transcriptional activity of the Tax-depleted extract can be restored by the 0.6 phosphocellulose fraction. Interestingly, a consensus binding site for cAMP-responsive element binding protein (CREB) is located upstream of the VA-I promoter, and deletion of this element results in the loss of Tax responsiveness. When this CREB binding site is replaced by a Gal-4 binding site, the VA-I promoter can be transactivated by a Gal4-Tax fusion protein. Taken together, these results suggest that Tax may activate pol III and pol II promoter through a similar mechanism involving the CREB activation pathway. It is also possible that Tax affects pol III transcription by direct interaction with a component of the pol III transcriptional machinery.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20501-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Human T-cell leukemia virus type I Tax protein transactivates RNA polymerase III promoter in vitro and in vivo.
pubmed:affiliation
Laboratory of Molecular Virology, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article, Comparative Study