Synergy between HIV-1 Tat and adenovirus E1A is principally due to stabilization of transcriptional elongation
- PMID: 2149119
- DOI: 10.1101/gad.4.12b.2397
Synergy between HIV-1 Tat and adenovirus E1A is principally due to stabilization of transcriptional elongation
Abstract
We studied the combined effects of Tat and general trans-activators, such as E1A and phorbol esters, on human immunodeficiency virus-1 (HIV-1) gene expression. Interaction between these two types of trans-activators may be involved in the transition from transcriptional quiesence during viral latency to active gene expression during productive infection. E1A cooperated with Tat to produce a fourfold greater increase in accumulation of full-length, cytoplasmic HIV-1-directed RNA than is expected if they were acting additively to increase RNA accumulation. Similarly, phorbol 12-myristate 13-acetate (PMA) also cooperated with Tat to elevate HIV RNA levels synergistically. Analysis of transcription rates across the HIV-1-directed transcription unit indicated, unexpectedly, that synergy between Tat and E1A could not be accounted for by increased promoter proximal transcription rates that were merely additive. However, Tat and E1A produced a greater than additive increase in transcription rates in the 3' end of the gene. These findings imply that synergy between Tat and E1A (or other general transcriptional activators) is due principally to stabilization of transcriptional elongation. Furthermore, the observation that Tat elicits only a small increase in promoter proximal transcription in the presence of E1A suggests that the magnitude of the effect of Tat on initiation is decreased when the basal level of transcription is increased. These findings underscore the importance of the ability of Tat to stabilize elongation, as well as to stimulate initiation, in an HIV-1-directed transcription unit.
Similar articles
-
Tat gets the "green" light on transcription initiation.Retrovirology. 2005 Nov 9;2:69. doi: 10.1186/1742-4690-2-69. Retrovirology. 2005. PMID: 16280076 Free PMC article. Review.
-
Multiple modes of transcriptional regulation by the HIV-1 Tat transactivator.IUBMB Life. 2001 Mar;51(3):175-81. doi: 10.1080/152165401753544241. IUBMB Life. 2001. PMID: 11547919 Review.
-
HIV-1 Tat protein increases transcriptional initiation and stabilizes elongation.Cell. 1989 Oct 20;59(2):283-92. doi: 10.1016/0092-8674(89)90290-0. Cell. 1989. PMID: 2553266
-
Tat transactivation of the human immunodeficiency virus type 1 promoter is influenced by basal promoter activity and the simian virus 40 origin of DNA replication.Proc Natl Acad Sci U S A. 1991 Nov 15;88(22):10018-22. doi: 10.1073/pnas.88.22.10018. Proc Natl Acad Sci U S A. 1991. PMID: 1658792 Free PMC article.
-
The VP16 transcription activation domain is functional when targeted to a promoter-proximal RNA sequence.Genes Dev. 1992 Nov;6(11):2077-87. doi: 10.1101/gad.6.11.2077. Genes Dev. 1992. PMID: 1427073
Cited by
-
Impact of Tat Genetic Variation on HIV-1 Disease.Adv Virol. 2012;2012:123605. doi: 10.1155/2012/123605. Epub 2012 Jul 30. Adv Virol. 2012. PMID: 22899925 Free PMC article.
-
HIV-1 Tat stimulates transcription complex assembly through recruitment of TBP in the absence of TAFs.PLoS Biol. 2005 Feb;3(2):e44. doi: 10.1371/journal.pbio.0030044. Epub 2005 Feb 8. PLoS Biol. 2005. PMID: 15719058 Free PMC article.
-
Characterization of a major histocompatibility complex class II X-box-binding protein enhancing tat-induced transcription directed by the human immunodeficiency virus type 1 long terminal repeat.J Virol. 2000 Oct;74(19):8989-9001. doi: 10.1128/jvi.74.19.8989-9001.2000. J Virol. 2000. PMID: 10982343 Free PMC article.
-
Tat modifies the activity of CDK9 to phosphorylate serine 5 of the RNA polymerase II carboxyl-terminal domain during human immunodeficiency virus type 1 transcription.Mol Cell Biol. 2000 Jul;20(14):5077-86. doi: 10.1128/MCB.20.14.5077-5086.2000. Mol Cell Biol. 2000. PMID: 10866664 Free PMC article.
-
Human and rodent transcription elongation factor P-TEFb: interactions with human immunodeficiency virus type 1 tat and carboxy-terminal domain substrate.J Virol. 1999 Jul;73(7):5448-58. doi: 10.1128/JVI.73.7.5448-5458.1999. J Virol. 1999. PMID: 10364292 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical