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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2002-11-13
pubmed:abstractText
The binding subunit of pertussis toxin (PTX-B) has been shown recently to inhibit the entry and postentry events in HIV-1 replication in primary T lymphocytes and monocyte-derived macrophages. While the effect of PTX-B on HIV-1 entry was shown to involve CCR5 desensitization, the mechanism of postentry inhibition remained unclear. In T lymphocytes, PTX-B affected transcription or stability of Tat-stimulated HIV-1 mRNAs. In this study, we sought to identify the mechanism of postentry inhibition of HIV-1 replication by PTX-B in U-937 promonocytic cells. We demonstrate that in these cells PTX-B inhibits expression of luciferase reporter gene controlled by the HIV-1 LTR promoter. This effect is Tat-independent and is not restricted to the HIV-1 LTR promoter. Instead, PTX-B activity is mediated through suppression of the cellular transcription factor, NF-kappaB. PTX-B inhibits phosphorylation and nuclear translocation of the p65 subunit of NF-kappaB. This effect is independent of the cytoplasmic NF-kappaB inhibitor, IkappaBalpha, as PTX-B stimulates phosphorylation and subsequent degradation of this protein. The suppressive activity of PTX-B on NF-kappaB p65 phosphorylation and nuclear translocation is delayed, suggesting that PTX-B signaling might initiate synthesis and cytoplasmic accumulation of a p65 phosphorylation inhibitor.
pubmed:language
eng
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:author
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
195-206
pubmed:dateRevised
2006-11-15
pubmed:articleTitle
B-oligomer of pertussis toxin inhibits HIV-1 LTR-driven transcription through suppression of NF-kappaB p65 subunit activity.
pubmed:affiliation
The D. I. Ivanovsky Institute of Virology, Russian Academy of Medical Science, Moscow, 123098, Russia.