The SNAP45 subunit of the small nuclear RNA (snRNA) activating protein complex is required for RNA polymerase II and III snRNA gene transcription and interacts with the TATA box binding protein.

Transcription of a Drosophila U1 small nuclear RNA gene was functionally analyzed in cell extracts derived from 0- to 12-h embryos. Two promoter elements essential for efficient initiation of transcription in vitro by RNA polymerase II were identified. The first, termed PSEA, is located between positions -41 and -61 relative to the transcription start site, is crucial for promoter activity, and is the dominant element for specifying the transcription initiation site. PSEA thus appears to be functionally homologous to the proximal sequence element of vertebrate small nuclear RNA genes. The second element, termed PSEB, is located at positions -25 to -32 and is required for an efficient level of transcription initiation because mutation of PSEB, or alteration of the spacing between PSEA and PSEB, severely reduced transcriptional activity relative to that of the wild-type promoter. Although the PSEB sequence does not have any obvious sequence similarity to a TATA box, conversion of PSEB to the canonical TATA sequence dramatically increased the efficiency of the U1 promoter and simultaneously relieved the requirement for the upstream PSEA. Despite these effects, introduction of the TATA sequence into the U1 promoter had no effect on the choice of start site or on the RNA polymerase II specificity of the promoter. Finally, evidence is presented that the TATA box-binding protein is required for transcription from the wild-type U1 promoter as well as from the TATA-containing U1 promoter.

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The gammaherpesviral TATA-box-binding protein directly interacts with the CTD of host RNA Pol II to direct late gene transcription

10.1101/2020.01.28.922526 ◽

2020 ◽

Author(s):

Angelica F. Castañeda ◽

Allison L. Didychuk ◽

Robert K. Louder ◽

Chloe O. McCollum ◽

Zoe H. Davis ◽

...

Keyword(s):

Rna Polymerase Ii ◽

Gene Transcription ◽

Binding Protein ◽

Tata Box ◽

Late Gene ◽

Rna Pol Ii ◽

Eukaryotic Transcription ◽

Pol Ii ◽

Terminal Domain ◽

Tata Box Binding Protein

ABSTRACTβ- and γ-herpesviruses include the oncogenic human viruses Kaposi’s sarcoma-associated virus (KSHV) and Epstein-Barr virus (EBV), and human cytomegalovirus (HCMV), which is a significant cause of congenital disease. Near the end of their replication cycle, these viruses transcribe their late genes in a manner distinct from host transcription. Late gene transcription requires six virally-encoded proteins, one of which is a functional mimic of host TATA-box-binding protein (TBP) that is also involved in recruitment of RNA polymerase II (Pol II) via unknown mechanisms. Here, we applied biochemical protein interaction studies together with electron microscopy-based imaging of a reconstituted human preinitiation complex to define the mechanism underlying Pol II recruitment. These data revealed that the herpesviral TBP, encoded by ORF24 in KSHV, makes a direct protein-protein contact with the C-terminal domain of host RNA polymerase II (Pol II), which is a unique feature that functionally distinguishes viral from cellular TBP. The interaction is mediated by the N-terminal domain (NTD) of ORF24 through a conserved motif that is shared in its β- and γ-herpesvirus homologs. Thus, these herpesviruses employ an unprecedented strategy in eukaryotic transcription, wherein promoter recognition and polymerase recruitment are facilitated by a single transcriptional activator with functionally distinct domains.SIGNIFICANCE STATEMENTThe β- and γ-herpesviruses mediate their late gene transcription through a set of viral transcriptional activators (vTAs). One of these vTAs, ORF24 in Kaposi’s sarcoma-associated herpesvirus (KSHV), is a mimic of host TATA-box-binding protein (TBP). We demonstrate that the N-terminal domain of ORF24 and its homologs from other β- and γ-herpesviruses directly bind the unstructured C-terminal domain (CTD) of RNA Pol II. This functionally distinguishes the viral TBP mimic from cellular TBP, which does not bind Pol II. Thus, herpesviruses encode a transcription factor that has the dual ability to directly interact with promoter DNA and the polymerase, a property which is unique in eukaryotic transcription and is conceptually akin to prokaryotic transcription factors.

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TAF15 (TAF15 RNA polymerase II, TATA box binding protein (TBP)-associated factor, 68kDa)

Atlas of Genetics and Cytogenetics in Oncology and Haematology ◽

10.4267/2042/37666 ◽

2011 ◽

Author(s):

JL Huret

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Ii ◽

Binding Protein ◽

Tata Box ◽

Associated Factor ◽

Tata Box Binding Protein

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In vitro transcription of a Drosophila U1 small nuclear RNA gene requires TATA box-binding protein and two proximal cis-acting elements with stringent spacing requirements.

Molecular and Cellular Biology ◽

10.1128/mcb.13.9.5918 ◽

1993 ◽

Vol 13 (9) ◽

pp. 5918-5927 ◽

Cited By ~ 18

Author(s):

Z Zamrod ◽

C M Tyree ◽

Y Song ◽

W E Stumph

Keyword(s):

Rna Polymerase Ii ◽

Transcription Initiation ◽

Tata Box ◽

Start Site ◽

Small Nuclear Rna ◽

Wild Type ◽

Nuclear Rna ◽

Tata Sequence ◽

Tata Box Binding Protein

Transcription of a Drosophila U1 small nuclear RNA gene was functionally analyzed in cell extracts derived from 0- to 12-h embryos. Two promoter elements essential for efficient initiation of transcription in vitro by RNA polymerase II were identified. The first, termed PSEA, is located between positions -41 and -61 relative to the transcription start site, is crucial for promoter activity, and is the dominant element for specifying the transcription initiation site. PSEA thus appears to be functionally homologous to the proximal sequence element of vertebrate small nuclear RNA genes. The second element, termed PSEB, is located at positions -25 to -32 and is required for an efficient level of transcription initiation because mutation of PSEB, or alteration of the spacing between PSEA and PSEB, severely reduced transcriptional activity relative to that of the wild-type promoter. Although the PSEB sequence does not have any obvious sequence similarity to a TATA box, conversion of PSEB to the canonical TATA sequence dramatically increased the efficiency of the U1 promoter and simultaneously relieved the requirement for the upstream PSEA. Despite these effects, introduction of the TATA sequence into the U1 promoter had no effect on the choice of start site or on the RNA polymerase II specificity of the promoter. Finally, evidence is presented that the TATA box-binding protein is required for transcription from the wild-type U1 promoter as well as from the TATA-containing U1 promoter.

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A Divergent Transcription Factor TFIIB in Trypanosomes Is Required for RNA Polymerase II-Dependent Spliced Leader RNA Transcription and Cell Viability

Eukaryotic Cell ◽

10.1128/ec.5.2.293-300.2006 ◽

2006 ◽

Vol 5 (2) ◽

pp. 293-300 ◽

Cited By ~ 32

Author(s):

Jennifer B. Palenchar ◽

Wenzhe Liu ◽

Peter M. Palenchar ◽

Vivian Bellofatto

Keyword(s):

Transcription Factor ◽

Rna Polymerase ◽

Rna Polymerase Ii ◽

Gene Transcription ◽

Binding Protein ◽

In Vitro Transcription ◽

Tata Binding Protein ◽

Small Nuclear Rna ◽

Spliced Leader

ABSTRACT Transcription by RNA polymerase II in trypanosomes deviates from the standard eukaryotic paradigm. Genes are transcribed polycistronically and subsequently cleaved into functional mRNAs, requiring trans splicing of a capped 39-nucleotide leader RNA derived from a short transcript, the spliced leader (SL) RNA. The only identified trypanosome RNA polymerase II promoter is that of the SL RNA gene. We have previously shown that transcription of SL RNA requires divergent trypanosome homologs of RNA polymerase II, TATA binding protein, and the small nuclear RNA (snRNA)-activating protein complex. In other eukaryotes, TFIIB is an additional key component of transcription for both mRNAs and polymerase II-dependent snRNAs. We have identified a divergent homolog of the usually highly conserved basal transcription factor, TFIIB, from the pathogenic parasite Trypanosoma brucei. T. brucei TFIIB (TbTFIIB) interacted directly with the trypanosome TATA binding protein and RNA polymerase II, confirming its identity. Functionally, in vitro transcription studies demonstrated that TbTFIIB is indispensable in SL RNA gene transcription. RNA interference (RNAi) studies corroborated the essential nature of TbTFIIB, as depletion of this protein led to growth arrest of parasites. Furthermore, nuclear extracts prepared from parasites depleted of TbTFIIB, after the induction of RNAi, required recombinant TbTFIIB to support spliced leader transcription. The information gleaned from TbTFIIB studies furthers our understanding of SL RNA gene transcription and the elusive overall transcriptional processes in trypanosomes.

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