Activation<i>in vitro</i>of RNA polymerase II and III directed transcription by baculovirus produced E1A protein

Patel, G. H.; Jones, Nicholas

doi:10.1093/nar/18.10.2909

Cited by 21 publications

(13 citation statements)

References 53 publications

(49 reference statements)

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“…Previous studies on the effects of viral infection on RNA pol III transcription have documented increases in the activity of the general pol III transcription factor TFIIIC. Notably, the adenovirus E1A protein has been shown to stimulate both the transcriptional activity and DNA binding activity of TFIIIC (8,17,25,29,30,37,60). Similarly, both the herpes simplex virus immediate-early protein ICP27 and the human immunodeficiency virus Tat protein have been reported to increase TFIIIC transcriptional activity (32,33).…”

Section: Discussionmentioning

confidence: 99%

Transcriptional Activation of RNA Polymerase III-Dependent Genes by the Human T-Cell Leukemia Virus Type 1 Tax Protein

Gottesfeld

Johnson

Nyborg

1996

Molecular and Cellular Biology

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The human T-cell leukemia virus-encoded Tax protein is a potent activator of many viral and cellular genes transcribed by RNA polymerase II. We find that both chromatin and cell extracts derived from human T-cell leukemia virus type 1-infected human T lymphocytes support higher levels of 5S rRNA and tRNA gene transcription than chromatin or extracts from uninfected T lymphocytes. The viral protein Tax was likely responsible for this higher level of class III gene transcription, as purified Tax was found to stimulate both genes when added to the uninfected cell extract or in reconstituted systems. Both limiting-component transcription assays and DNA binding assays identified the class III gene transcription factor TFIIIB as the principal target of Tax activity. Surprisingly, we find that Tax increases the effective concentration of active TFIIIB molecules. These data suggest that Tax stimulates RNA polymerase III-dependent gene expression by accelerating the rate and/or extent of transcription initiation complex assembly.Human T-cell leukemia virus type 1 (HTLV-1) is the causative agent of an aggressive and fatal malignancy called adult T-cell leukemia (39; for a review, see reference 21). The virus is also associated with a variety of additional clinical disorders in humans, including a neurodegenerative disease called tropical spastic paraparesis/HTLV-1-associated myelopathy (31). The pathogenesis of HTLV-1 appears directly linked to the virally encoded transcriptional activator protein Tax. Tax is essential to the life cycle of the virus, as it strongly stimulates RNA polymerase II (pol II)-dependent transcription of the HTLV-1 genome, thus leading to efficient viral replication (14,15,19,23,44,48). Tax has also been shown to deregulate the expression of a wide variety of class II cellular genes, leading to the hypothesis that HTLV-1-associated pathogenesis may result from the highly pleiotropic deregulation of cellular gene expression by Tax.Tax does not bind DNA directly but instead utilizes a variety of structurally unrelated cellular DNA-binding proteins to mediate transcriptional deregulation. For example, Tax strongly up-regulates HTLV-1 gene expression apparently mediated through the cellular protein CREB, a member of the basic leucine zipper (bZIP) family of transcription factors (7,12,20,59). Tax also stimulates the expression of a wide variety of class II viral and cellular genes mediated through additional cellular transcription factors. These processes include the transcriptional up-regulation of human immunodeficiency virus, interleukin 2, and interleukin 2 receptor ␣ genes mediated through members of the NF-B family of proteins (5, 10, 41, 45) and transcriptional up-regulation of the c-fos, Krox-20 and Krox-24 genes mediated through serum response factor (1, 2, 22). Interestingly, the basic helix-loop-helix proteins, which play critical roles in cellular proliferation and differentiation, appear to be involved in Tax-mediated repression of gene expression (51).The precise molecular steps leading ...

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Section: Discussionmentioning

confidence: 99%

Transcriptional Activation of RNA Polymerase III-Dependent Genes by the Human T-Cell Leukemia Virus Type 1 Tax Protein

Gottesfeld

Johnson

Nyborg

1996

Molecular and Cellular Biology

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“…This system was likely to be advantageous over a prokaryotic expression system because many proteins produced in this manner arc soluble and the insect cells can carry out certain eukaryotic post-translational modifications such as phosphorylation (Miyamoto et al 1985;Olio and iMamatis 1987). In addition, several reports demonstrate that recombinant transcriptional regulators produced by this system are active in vitro (Patel and Jones 1990;Watson and Hay 1990). cDNA cloning studies of both mouse and human p50 have suggested that it is primarily synthesized as a larger precursor protein, pi05, and may be matured by proteolytic removal of its carboxyl region.…”

Section: Nf-kb Subunits P50 and P65mentioning

confidence: 99%

Independent modes of transcriptional activation by the p50 and p65 subunits of NF-kappa B.

Fujita¹,

Nolan²,

Ghosh³

et al. 1992

Genes Dev.

366

273

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Recombinant subunits of the transcription factor NF-KB, p50 and p65, were analyzed both for binding to various KB motifs and in vitro activation. The subunits preferentially form a heterodimer that activates transcription. Although p50 and p65 bind DNA individually as homodimers and are structurally related, their activation mechanisms are distinct. p65 activates transcription by its unique carboxy-terminal activation domain. (pSOjj displays higher affinity DNA binding than (p65)2 for many distinct KB motifs and provides strong transcriptional activation only when adopting a chymotrypsin-resistant conformation induced by certain KB motifs but not others. Thus, (pSOjj acts as a positive regulator in vitro, consistent with its isolation as a putative constitutive regulator of MHC class I genes. Both subunits of NF-KB, therefore, contribute independently to provide regulation at given KB motifs.

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“…Owing to this large genome size it is not possible to insert foreign DNA by conventional techniques such as the use of restriction endonuclease cleavage sites. The method used therefore, relies upon homologous recombination between viral DNA and an appropriate transfer vector when cotransfected into insect cells (5)(6)(7)(8)(9). The transfer vector consists of the recombinant gene inserted downstream of the polyhedrin promoter flanked by the same sequences that flank the polyhedrin gene in the intact virus.…”

Section: Introductionmentioning

confidence: 99%

A new method for the isolation of recombinant baculovirus

Patel¹,

Nasmyth

Jones³

1992

Nucl Acids Res

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An improved method for the isolation of baculovirus recombinants is described. The method involves the replication and maintenance of the baculovirus genome in the yeast Saccharomyces cerevisiae which was accomplished by the isolation of a baculovirus recombinant containing yeast ARS and CEN sequences ensuring stable replication in yeast and a URA3 selectable marker. The viral DNA maintained its ability to replicate in insect cells. An efficient and rapid selection system was set up, to isolate viral recombinants in yeast; DNA from selected yeast colonies was transfected into insect cells to obtain recombinant virus. We demonstrate the utility of this system by isolating recombinant viruses that express two different members of the CREB/ATF family of transcription factors.

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Activationin vitroof RNA polymerase II and III directed transcription by baculovirus produced E1A protein

Cited by 21 publications

References 53 publications

Transcriptional Activation of RNA Polymerase III-Dependent Genes by the Human T-Cell Leukemia Virus Type 1 Tax Protein

Transcriptional Activation of RNA Polymerase III-Dependent Genes by the Human T-Cell Leukemia Virus Type 1 Tax Protein

Independent modes of transcriptional activation by the p50 and p65 subunits of NF-kappa B.

A new method for the isolation of recombinant baculovirus

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