scholarly journals Modulation of Yeast Genome Expression in Response to Defective RNA Polymerase III-Dependent Transcription

2005 ◽  
Vol 25 (19) ◽  
pp. 8631-8642 ◽  
Author(s):  
Christine Conesa ◽  
Roberta Ruotolo ◽  
Pascal Soularue ◽  
Tiffany A. Simms ◽  
David Donze ◽  
...  

ABSTRACT We used genome-wide expression analysis in Saccharomyces cerevisiae to explore whether and how the expression of protein-coding, RNA polymerase (Pol) II-transcribed genes is influenced by a decrease in RNA Pol III-dependent transcription. The Pol II transcriptome was characterized in four thermosensitive, slow-growth mutants affected in different components of the RNA Pol III transcription machinery. Unexpectedly, we found only a modest correlation between altered expression of Pol II-transcribed genes and their proximity to class III genes, a result also confirmed by the analysis of single tRNA gene deletants. Instead, the transcriptome of all of the four mutants was characterized by increased expression of genes known to be under the control of the Gcn4p transcriptional activator. Indeed, GCN4 was found to be translationally induced in the mutants, and deleting the GCN4 gene eliminated the response. The Gcn4p-dependent expression changes did not require the Gcn2 protein kinase and could be specifically counteracted by an increased gene dosage of initiator tRNAMet. Initiator tRNAMet depletion thus triggers a GCN4-dependent reprogramming of genome expression in response to decreased Pol III transcription. Such an effect might represent a key element in the coordinated transcriptional response of yeast cells to environmental changes.

2021 ◽  
Author(s):  
Sarah E Dremel ◽  
Frances L Sivrich ◽  
Jessica M Tucker ◽  
Britt A Glaunsinger ◽  
Neal A DeLuca

RNA Polymerase III (Pol III) transcribes noncoding RNA, including transfer RNA (tRNA), and acts as a pathogen sensor during the innate immune response. To promote enhanced proliferation, the Pol III machinery is commonly targeted during cancer and viral infection. Herein we employ DM-RNA-Seq, 4SU-Seq, ChIP-Seq, and ATAC-Seq to characterize how Herpes Simplex Virus-1 (HSV-1) perturbs the Pol III landscape. We find that HSV-1 stimulates tRNA expression 10-fold, with mature tRNAs exhibiting a 2-fold increase within 12 hours of infection. Perturbation of host tRNA synthesis requires nuclear viral entry, but not synthesis of specific viral transcripts, nascent viral genomes, or viral progeny. Host tRNA with a specific codon bias were not targeted, rather increased transcription was observed from euchromatic, actively transcribed loci. tRNA upregulation is linked to unique crosstalk between the Pol II and III transcriptional machinery. While viral infection is known to mediate host transcriptional shut off and lead to a depletion of Pol II on host mRNA promoters, we find that Pol II binding to tRNA loci increases. Finally, we report Pol III and associated factors bind the HSV genome, which suggests a previously unrecognized role in HSV-1 gene expression. These data provide insight into novel mechanisms by which HSV-1 alters the host nuclear environment, shifting key processes in favor of the pathogen.


2020 ◽  
pp. jbc.RA120.015386
Author(s):  
Zongliang Gao ◽  
Yme Ubeles van der Velden ◽  
Minghui Fan ◽  
Cynthia Alyssa van der Linden ◽  
Monique Vink ◽  
...  

RNA polymerase III promoters such as 7SK, U6 and H1 are widely used for the expression of small non-coding RNAs, including short hairpin RNAs for RNAi experiments and guide RNAs for CRISPR-mediated genome editing. We previously reported dual RNA polymerase activity (Pol II/III) for the human H1 promoter and demonstrated that this promiscuous RNA polymerase use can be exploited for the simultaneous expression of both a non-coding RNA and an mRNA. However, this combination is not a desired feature in other experimental and therapeutic settings. To overcome this limitation of the H1 promoter we engineered a miniature H1/7SK hybrid promoter with minimal Pol II activity, thereby boosting the Pol III activity to a level that is higher than that of either parental promoter. In parallel, we also engineered small Pol II-specific H1 promoter variants and explored their use as general Pol II promoters for protein expression. The newly engineered promoter variants form an attractive alternative to the commonly-used H1 promoter in terms of activity and small promoter size, but also concerning safety by exclusive expression of the desired therapeutic transcript (either Pol II or Pol III, but not both).


2018 ◽  
Author(s):  
Zheng Wang ◽  
Catherine Wu ◽  
Aaron Aslanian ◽  
John R. Yates ◽  
Tony Hunter

ABSTRACTTranscription by RNA polymerase III (Pol III) is an essential cellular process, and mutations in Pol III can cause neurodegenerative disease in humans. However, in contrast to Pol II transcription, which has been extensively studied, the knowledge of how Pol III is regulated is very limited. We report here that in budding yeast, Saccharomyces cerevisiae, Pol III is negatively regulated by the Small Ubiquitin-like MOdifier (SUMO), an essential post-translational modification pathway. Besides sumoylation, Pol III is also targeted by ubiquitylation and the Cdc48/p97 segregase, the three of which likely act in a sequential manner and eventually lead to proteasomal degradation of Pol III subunits, thereby repressing Pol III transcription. This study not only uncovered a regulatory mechanism for Pol III, but also suggests that the SUMO and ubiquitin modification pathways and the Cdc48/p97 segregase can be potential therapeutic targets for Pol III-related human diseases.


1994 ◽  
Vol 14 (9) ◽  
pp. 5910-5919
Author(s):  
S Connelly ◽  
C Marshallsay ◽  
D Leader ◽  
J W Brown ◽  
W Filipowicz

RNA polymerase (Pol) II- and RNA Pol III-transcribed small nuclear RNA (snRNA) genes of dicotyledonous plants contain two essential upstream promoter elements, the USE and TATA. The USE is a highly conserved plant snRNA gene-specific element, and its distance from the -30 TATA box, corresponding to approximately three and four helical DNA turns in Pol III and Pol II genes, respectively, is crucial for determining RNA Pol specificity of transcription. Sequences upstream of the USE play no role in snRNA gene transcription in dicot plants. Here we show that for expression of snRNA genes in maize, a monocotyledonous plant, the USE and TATA elements are essential, but not sufficient, for transcription. Efficient expression of both Pol II- and Pol III-specific snRNA genes in transfected maize protoplasts requires an additional element(s) positioned upstream of the USE. This element, named MSP (for monocot-specific promoter; consensus, RGCCCR), is present in one to three copies in monocot snRNA genes and is interchangeable between Pol II- and Pol III-specific genes. The efficiency of snRNA gene expression in maize protoplast is determined primarily by the strength of the MSP element(s); this contrasts with the situation in protoplasts of a dicot plant, Nicotiana plumbaginifolia, where promoter strength is a function of the quality of the USE element. Interestingly, the organization of monocot Pol III-specific snRNA gene promoters closely resembles those of equivalent vertebrate promoters. The data are discussed in the context of the coevolution of Pol II- and Pol III-specific snRNA gene promoters within many eukaryotic organisms.


2005 ◽  
Vol 25 (21) ◽  
pp. 9406-9418 ◽  
Author(s):  
Ashish Saxena ◽  
Beicong Ma ◽  
Laura Schramm ◽  
Nouria Hernandez

ABSTRACT The transcription factors TFIIB, Brf1, and Brf2 share related N-terminal zinc ribbon and core domains. TFIIB bridges RNA polymerase II (Pol II) with the promoter-bound preinitiation complex, whereas Brf1 and Brf2 are involved, as part of activities also containing TBP and Bdp1 and referred to here as Brf1-TFIIIB and Brf2-TFIIIB, in the recruitment of Pol III. Brf1-TFIIIB recruits Pol III to type 1 and 2 promoters and Brf2-TFIIIB to type 3 promoters such as the human U6 promoter. Brf1 and Brf2 both have a C-terminal extension absent in TFIIB, but their C-terminal extensions are unrelated. In yeast Brf1, the C-terminal extension interacts with the TBP/TATA box complex and contributes to the recruitment of Bdp1. Here we have tested truncated Brf2, as well as Brf2/TFIIB chimeric proteins for U6 transcription and for assembly of U6 preinitiation complexes. Our results characterize functions of various human Brf2 domains and reveal that the C-terminal domain is required for efficient association of the protein with U6 promoter-bound TBP and SNAPc, a type 3 promoter-specific transcription factor, and for efficient recruitment of Bdp1. This in turn suggests that the C-terminal extensions in Brf1 and Brf2 are crucial to specific recruitment of Pol III over Pol II.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthias K. Vorländer ◽  
Anna Jungblut ◽  
Kai Karius ◽  
Florence Baudin ◽  
Helga Grötsch ◽  
...  

Abstract Transcription factor (TF) IIIC is a conserved eukaryotic six-subunit protein complex with dual function. It serves as a general TF for most RNA polymerase (Pol) III genes by recruiting TFIIIB, but it is also involved in chromatin organization and regulation of Pol II genes through interaction with CTCF and condensin II. Here, we report the structure of the S. cerevisiae TFIIIC subcomplex τA, which contains the most conserved subunits of TFIIIC and is responsible for recruitment of TFIIIB and transcription start site (TSS) selection at Pol III genes. We show that τA binding to its promoter is auto-inhibited by a disordered acidic tail of subunit τ95. We further provide a negative-stain reconstruction of τA bound to the TFIIIB subunits Brf1 and TBP. This shows that a ruler element in τA achieves positioning of TFIIIB upstream of the TSS, and suggests remodeling of the complex during assembly of TFIIIB by TFIIIC.


2003 ◽  
Vol 14 (6) ◽  
pp. 2425-2435 ◽  
Author(s):  
Chen Wang ◽  
Joan C. Politz ◽  
Thoru Pederson ◽  
Sui Huang

The perinucleolar compartment (PNC) is a nuclear substructure present in transformed cells. The PNC is defined by high concentrations of certain RNA binding proteins and a subset of small RNAs transcribed by RNA polymerase III (pol III), including the signal recognition particle RNA and an Alu RNA as reported here. To determine if the PNC is dependent on pol III transcription, HeLa cells were microinjected with the selective pol III inhibitor, Tagetin. This resulted in disassembly of the PNC, whereas inhibition of pol I by cycloheximide or pol II by α-amanitin did not significantly affect the PNC. However, overexpression of one of the PNC-associated RNAs from a pol II promoter followed by injection of Tagetin blocked the Tagetin-induced PNC disassembly, demonstrating that it is the RNA rather than pol III activity that is important for the PNC integrity. To elucidate the role of the PNC-associated protein PTB, its synthesis was inhibited by siRNA. This resulted in a reduction of the number of PNC-containing cells and the PNC size. Together, these findings suggest, as a working model, that PNCs may be involved in the metabolism of specific pol III transcripts in the transformed state and that PTB is one of the key elements mediating this process.


2018 ◽  
Author(s):  
Pratibha Bhalla ◽  
Dipti Vernekar ◽  
Ashutosh Shukla ◽  
Benoit Gilquin ◽  
Yohann Couté ◽  
...  

AbstractMany regulatory proteins and complexes influence transcription by RNA polymerase (pol) II. In comparison, only a few regulatory proteins are known for pol III, which transcribes mostly house-keeping and non-coding genes. Yet, pol III transcription is precisely regulated under various stress conditions like starvation. We used pol III transcription complex components TFIIIC (Tfc6), pol III (Rpc128) and TFIIIB (Brf1) as baits to identify potential interactors through mass spectrometry-based proteomics. A large interactome constituting known chromatin modifiers, factors and regulators of transcription by pol I and pol II revealed the possibility of a large number of signaling cues for pol III transcription against adverse conditions. We found one of the pol II-associated factors, Paf1 complex (PAF1C) interacts with the three baits. Its occupancy on the pol III-transcribed genes is low and not correlated with pol III occupancy. Paf1 deletion leads to higher occupancy of pol III, γ-H2A and DNA pol2 but no change in nucleosome positions. Genotoxins exposure causes pol III but not Paf1 loss from the genes. PAF1C promotes the pol III pausing and restricts its accumulation on the genes, which reduces the replication stress caused by the pol III barrier and transcription-replication conflict on these highly transcribed genes.


2014 ◽  
Vol 14 (3) ◽  
pp. 216-227 ◽  
Author(s):  
Norma E. Padilla-Mejía ◽  
Luis E. Florencio-Martínez ◽  
Rodrigo Moreno-Campos ◽  
Juan C. Vizuet-de-Rueda ◽  
Ana M. Cevallos ◽  
...  

ABSTRACT Eukaryotic tRNAs, transcribed by RNA polymerase III (Pol III), contain boxes A and B as internal promoter elements. One exception is the selenocysteine (Sec) tRNA (tRNA-Sec), whose transcription is directed by an internal box B and three extragenic sequences in vertebrates. Here we report on the transcriptional analysis of the tRNA-Sec gene in the protozoan parasite Leishmania major . This organism has unusual mechanisms of gene expression, including Pol II polycistronic transcription and maturation of mRNAs by trans splicing, a process that attaches a 39-nucleotide miniexon to the 5′ end of all the mRNAs. In L. major , tRNA-Sec is encoded by a single gene inserted into a Pol II polycistronic unit, in contrast to most tRNAs, which are clustered at the boundaries of polycistronic units. 5′ rapid amplification of cDNA ends and reverse transcription-PCR experiments showed that some tRNA-Sec transcripts contain the miniexon at the 5′ end and a poly(A) tail at the 3′ end, indicating that the tRNA-Sec gene is polycistronically transcribed by Pol II and processed by trans splicing and polyadenylation, as was recently reported for the tRNA-Sec genes in the related parasite Trypanosoma brucei . However, nuclear run-on assays with RNA polymerase inhibitors and with cells that were previously UV irradiated showed that the tRNA-Sec gene in L. major is also transcribed by Pol III. Thus, our results indicate that RNA polymerase specificity in Leishmania is not absolute in vivo , as has recently been found in other eukaryotes.


2003 ◽  
Vol 23 (1) ◽  
pp. 195-205 ◽  
Author(s):  
Magali Siaut ◽  
Cécile Zaros ◽  
Emilie Levivier ◽  
Maria-Laura Ferri ◽  
Magali Court ◽  
...  

ABSTRACT The essential C17 subunit of yeast RNA polymerase (Pol) III interacts with Brf1, a component of TFIIIB, suggesting a role for C17 in the initiation step of transcription. The protein sequence of C17 (encoded by RPC17) is conserved from yeasts to humans. However, mammalian homologues of C17 (named CGRP-RCP) are known to be involved in a signal transduction pathway related to G protein-coupled receptors, not in transcription. In the present work, we first establish that human CGRP-RCP is the genuine orthologue of C17. CGRP-RCP was found to functionally replace C17 in Δrpc17 yeast cells; the purified mutant Pol III contained CGRP-RCP and had a decreased specific activity but initiated faithfully. Furthermore, CGRP-RCP was identified by mass spectrometry in a highly purified human Pol III preparation. These results suggest that CGRP-RCP has a dual function in mammals. Next, we demonstrate by genetic and biochemical approaches that C17 forms with C25 (encoded by RPC25) a heterodimer akin to Rpb4/Rpb7 in Pol II. C17 and C25 were found to interact genetically in suppression screens and physically in coimmunopurification and two-hybrid experiments. Sequence analysis and molecular modeling indicated that the C17/C25 heterodimer likely adopts a structure similar to that of the archaeal RpoE/RpoF counterpart of the Rpb4/Rpb7 complex. These RNA polymerase subunits appear to have evolved to meet the distinct requirements of the multiple forms of RNA polymerases.


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