General transcription factors and subunits of RNA polymerase III

Institut National de la Santé et de la Recherche Médicale (INSERM) U869
Transcription 01/2010; 1(3):130-135. DOI: 10.4161/trns.1.3.13192
Source: PubMed


In the course of evolution of multi-cellular eukaryotes, paralogs of general transcription factors and RNA polymerase subunits emerged. Paralogs of transcription factors and of the RPC32 subunit of RNA polymerase III play important roles in cell type- and promoter-specific transcription. Here we discuss their respective functions.

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Available from: Giorgio Dieci, Jan 15, 2015
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    • "Yeast Pol III consists of 17 subunits which have structural and functional homologs in human cells. Transcription of tRNA genes requires the multisubunit initiation factors TFIIIB and TFIIIC which specifically bind to internal control regions [1] [2]. "
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    • "TBP and two RNAP-III-specific TAFs (BrfI and BdpI) assemble into the TFIIIB complex, which is involved in RNAP-III transcription. In vertebrates, there are two versions of TFIIIB complex containing either BrfI or its homolog BrfII (reviewed in [16]). Besides TFIIIB, TBP also interacts with the snRNA activating protein complex (SNAPc) at the human U6 promoter [17]. "
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    • "These findings anticipated the crucial discovery of TBP as a universal core TF, participating in the inner workings of all the three eukaryotic transcription machineries (Hernandez, 1993; Rigby, 1993; White et al., 1992), a property that was also already known for five subunits shared by the three nuclear RNA polymerases (Carles et al., 1991). Since then, the sharing of components by the three transcription systems, or the presence of paralogous polypeptides playing similar functions in different systems, has perhaps become less surprising, but not less challenging in terms of mechanistic interpretation (Carter and Drouin, 2010; Geiger et al., 2010; Kassavetis et al., 2010; Lefevre et al., 2011; Teichmann et al., 2010). As significant examples, we mention in particular the Pol II elongation factor TFIIS and the Pol II coactivator protein Sub1, that have recently been located at Pol IIItranscribed genes in S. cerevisiae by genome-wide studies, but whose function in transcription of these genes is only partially understood (Ghavi-Helm et al., 2008; Rosonina et al., 2009; Tavenet et al., 2009). "
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