Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
1998-9-10
pubmed:abstractText
Transcription of the human immunodeficiency virus type-1 (HIV-1) genome is controlled by cooperative interaction of viral encoded proteins and host regulatory proteins. In this study, we have examined the capacity of the viral auxiliary protein, Vpr, to modulate transcriptional activity of the HIV-1 promoter sequence located within the long terminal repeat (LTR). We demonstrate that ectopic expression of Vpr in human astrocytic cells, U-87MG, enhances the basal activity of the viral promoter in transfected cells and that the GC-rich sequences, spanning nucleotides -80 to -43, are important for this activity. Since this region serves as the target for p53-induced suppression of LTR activity and interacts with the ubiquitous transcription factor, Sp1, we examined the cooperative activity of Vpr, p53, and Sp1 upon LTR transcription. Results from co-transfection studies indicated that overexpression of wild type p53, but not mutant p53, decreases the level of activation of the LTR by Vpr. Transcriptional activation of the LTR by Vpr required the presence of Sp1 since overexpression of Vpr in cells with no endogenous Sp1 failed to augment LTR activity. Results from protein-protein interaction studies indicated that Vpr is associated with both p53 and Sp1 in cells with ectopic expression of these proteins. Moreover, it was evident that p53 and Sp1 interact with each other in these cells. These functional and structural studies provided a working model on the cooperative interaction of Vpr with cellular proteins Sp1 and p53 and control of viral gene transcription at immediate early stage of infection prior to the participation of other viral regulatory proteins.
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
7
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20052-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Cooperative actions of HIV-1 Vpr and p53 modulate viral gene transcription.
pubmed:affiliation
Center for NeuroVirology and NeuroOncology, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.