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Rosón JN, Vitarelli MDO, Costa-Silva HM, Pereira KS, Pires DDS, Lopes LDS, Cordeiro B, Kraus AJ, Cruz KNT, Calderano SG, Fragoso SP, Siegel TN, Elias MC, da Cunha JPC. H2B.V demarcates divergent strand-switch regions, some tDNA loci, and genome compartments in Trypanosoma cruzi and affects parasite differentiation and host cell invasion. PLoS Pathog 2022; 18:e1009694. [PMID: 35180281 PMCID: PMC8893665 DOI: 10.1371/journal.ppat.1009694] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 03/03/2022] [Accepted: 01/31/2022] [Indexed: 11/19/2022] Open
Abstract
Histone variants play a crucial role in chromatin structure organization and gene expression. Trypanosomatids have an unusual H2B variant (H2B.V) that is known to dimerize with the variant H2A.Z generating unstable nucleosomes. Previously, we found that H2B.V protein is enriched in tissue-derived trypomastigote (TCT) life forms, a nonreplicative stage of Trypanosoma cruzi, suggesting that this variant may contribute to the differences in chromatin structure and global transcription rates observed among parasite life forms. Here, we performed the first genome-wide profiling of histone localization in T. cruzi using epimastigotes and TCT life forms, and we found that H2B.V was preferentially located at the edges of divergent transcriptional strand switch regions, which encompass putative transcriptional start regions; at some tDNA loci; and between the conserved and disrupted genome compartments, mainly at trans-sialidase, mucin and MASP genes. Remarkably, the chromatin of TCT forms was depleted of H2B.V-enriched peaks in comparison to epimastigote forms. Interactome assays indicated that H2B.V associated specifically with H2A.Z, bromodomain factor 2, nucleolar proteins and a histone chaperone, among others. Parasites expressing reduced H2B.V levels were associated with higher rates of parasite differentiation and mammalian cell infectivity. Taken together, H2B.V demarcates critical genomic regions and associates with regulatory chromatin proteins, suggesting a scenario wherein local chromatin structures associated with parasite differentiation and invasion are regulated during the parasite life cycle.
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Affiliation(s)
- Juliana Nunes Rosón
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina–UNIFESP, São Paulo, Brazil
| | - Marcela de Oliveira Vitarelli
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Héllida Marina Costa-Silva
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Kamille Schmitt Pereira
- Department of Bioprocesses and Biotechnology, Universidade Federal do Paraná, Curitiba, Brazil
- Laboratory of Molecular and Systems Biology of Trypanosomatids, Carlos Chagas Institute, FIOCRUZ, Curitiba, Brazil
| | - David da Silva Pires
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Leticia de Sousa Lopes
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Barbara Cordeiro
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Amelie J. Kraus
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität in Munich, Munich, Germany
- Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universitäat in Munch, Munich, Germany
| | - Karin Navarro Tozzi Cruz
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Simone Guedes Calderano
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Stenio Perdigão Fragoso
- Department of Bioprocesses and Biotechnology, Universidade Federal do Paraná, Curitiba, Brazil
- Laboratory of Molecular and Systems Biology of Trypanosomatids, Carlos Chagas Institute, FIOCRUZ, Curitiba, Brazil
| | - T. Nicolai Siegel
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität in Munich, Munich, Germany
- Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universitäat in Munch, Munich, Germany
| | - Maria Carolina Elias
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Julia Pinheiro Chagas da Cunha
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
- * E-mail:
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2
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Reprogramming mRNA Expression in Response to Defect in RNA Polymerase III Assembly in the Yeast Saccharomyces cerevisiae. Int J Mol Sci 2021; 22:ijms22147298. [PMID: 34298922 PMCID: PMC8306304 DOI: 10.3390/ijms22147298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/25/2021] [Accepted: 07/03/2021] [Indexed: 12/18/2022] Open
Abstract
The coordinated transcription of the genome is the fundamental mechanism in molecular biology. Transcription in eukaryotes is carried out by three main RNA polymerases: Pol I, II, and III. One basic problem is how a decrease in tRNA levels, by downregulating Pol III efficiency, influences the expression pattern of protein-coding genes. The purpose of this study was to determine the mRNA levels in the yeast mutant rpc128-1007 and its overdose suppressors, RBS1 and PRT1. The rpc128-1007 mutant prevents assembly of the Pol III complex and functionally mimics similar mutations in human Pol III, which cause hypomyelinating leukodystrophies. We applied RNAseq followed by the hierarchical clustering of our complete RNA-seq transcriptome and functional analysis of genes from the clusters. mRNA upregulation in rpc128-1007 cells was generally stronger than downregulation. The observed induction of mRNA expression was mostly indirect and resulted from the derepression of general transcription factor Gcn4, differently modulated by suppressor genes. rpc128-1007 mutation, regardless of the presence of suppressors, also resulted in a weak increase in the expression of ribosome biogenesis genes. mRNA genes that were downregulated by the reduction of Pol III assembly comprise the proteasome complex. In summary, our results provide the regulatory links affected by Pol III assembly that contribute differently to cellular fitness.
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Bhargava P. Regulatory networking of the three RNA polymerases helps the eukaryotic cells cope with environmental stress. Curr Genet 2021; 67:595-603. [PMID: 33778898 DOI: 10.1007/s00294-021-01179-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 01/25/2023]
Abstract
Environmental stress influences the cellular physiology in multiple ways. Transcription by all the three RNA polymerases (Pols I, II, or III) in eukaryotes is a highly regulated process. With latest advances in technology, which have made many extensive genome-wide studies possible, it is increasingly recognized that all the cellular processes may be interconnected. A comprehensive view of the current research observations brings forward an interesting possibility that Pol II-associated factors may be directly involved in the regulation of expression from the Pol III-transcribed genes and vice versa, thus enabling a cross-talk between the two polymerases. An equally important cross-talk between the Pol I and Pol II/III has also been documented. Collectively, these observations lead to a change in the current perception that looks at the transcription of a set of genes transcribed by the three Pols in isolation. Emergence of an inclusive perspective underscores that all stress signals may converge on common mechanisms of transcription regulation, requiring an extensive cross-talk between the regulatory partners. Of the three RNA polymerases, Pol III turns out as the hub of these cross-talks, an essential component of the cellular stress-response under which the majority of the cellular transcriptional activity is shut down or re-aligned.
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Affiliation(s)
- Purnima Bhargava
- Centre for Cellular and Molecular Biology, (Council of Scientific and Industrial Research), Uppal Road, Hyderabad, 500007, India.
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TDP-43 regulates transcription at protein-coding genes and Alu retrotransposons. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194434. [PMID: 31655156 DOI: 10.1016/j.bbagrm.2019.194434] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 12/13/2022]
Abstract
The 43-kDa transactive response DNA-binding protein (TDP-43) is an example of an RNA-binding protein that regulates RNA metabolism at multiple levels from transcription and splicing to translation. Its role in post-transcriptional RNA processing has been a primary focus of recent research, but its role in regulating transcription has been studied for only a few human genes. We characterized the effects of TDP-43 on transcription genome-wide and found that TDP-43 broadly affects transcription of protein-coding and noncoding RNA genes. Among protein-coding genes, the effects of TDP-43 were greatest for genes <30 thousand base pairs in length. Surprisingly, we found that the loss of TDP-43 resulted in increased evidence for transcription activity near repetitive Alu elements found within expressed genes. The highest densities of affected Alu elements were found in the shorter genes, whose transcription was most affected by TDP-43. Thus, in addition to its role in post-transcriptional RNA processing, TDP-43 plays a critical role in maintaining the transcriptional stability of protein-coding genes and transposable DNA elements.
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Emamjomeh A, Zahiri J, Asadian M, Behmanesh M, Fakheri BA, Mahdevar G. Identification, Prediction and Data Analysis of Noncoding RNAs: A Review. Med Chem 2019; 15:216-230. [PMID: 30484409 DOI: 10.2174/1573406414666181015151610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 06/03/2018] [Accepted: 09/30/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Noncoding RNAs (ncRNAs) which play an important role in various cellular processes are important in medicine as well as in drug design strategies. Different studies have shown that ncRNAs are dis-regulated in cancer cells and play an important role in human tumorigenesis. Therefore, it is important to identify and predict such molecules by experimental and computational methods, respectively. However, to avoid expensive experimental methods, computational algorithms have been developed for accurately and fast prediction of ncRNAs. OBJECTIVE The aim of this review was to introduce the experimental and computational methods to identify and predict ncRNAs structure. Also, we explained the ncRNA's roles in cellular processes and drugs design, briefly. METHOD In this survey, we will introduce ncRNAs and their roles in biological and medicinal processes. Then, some important laboratory techniques will be studied to identify ncRNAs. Finally, the state-of-the-art models and algorithms will be introduced along with important tools and databases. RESULTS The results showed that the integration of experimental and computational approaches improves to identify ncRNAs. Moreover, the high accurate databases, algorithms and tools were compared to predict the ncRNAs. CONCLUSION ncRNAs prediction is an exciting research field, but there are different difficulties. It requires accurate and reliable algorithms and tools. Also, it should be mentioned that computational costs of such algorithm including running time and usage memory are very important. Finally, some suggestions were presented to improve computational methods of ncRNAs gene and structural prediction.
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Affiliation(s)
- Abbasali Emamjomeh
- Laboratory of Computational Biotechnology and Bioinformatics (CBB), Department of Plant Breeding and Biotechnology (PBB), University of Zabol, Zabol, Iran
| | - Javad Zahiri
- Bioinformatics and Computational Omics Lab (BioCOOL), Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mehrdad Asadian
- Department of Plant Breeding and Biotechnology (PBB), Faculty of Agriculture, University of Zabol, Zabol, Iran
| | - Mehrdad Behmanesh
- Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Barat A Fakheri
- Department of Plant Breeding and Biotechnology (PBB), Faculty of Agriculture, University of Zabol, Zabol, Iran
| | - Ghasem Mahdevar
- Department of Mathematics, Faculty of Sciences, University of Isfahan, Isfahan, Iran
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6
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Sun Y, Zhang H, Kazemian M, Troy JM, Seward C, Lu X, Stubbs L. ZSCAN5B and primate-specific paralogs bind RNA polymerase III genes and extra-TFIIIC (ETC) sites to modulate mitotic progression. Oncotarget 2018; 7:72571-72592. [PMID: 27732952 PMCID: PMC5340127 DOI: 10.18632/oncotarget.12508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 09/20/2016] [Indexed: 11/25/2022] Open
Abstract
Mammalian genomes contain hundreds of genes transcribed by RNA Polymerase III (Pol III), encoding noncoding RNAs and especially the tRNAs specialized to carry specific amino acids to the ribosome for protein synthesis. In addition to this well-known function, tRNAs and their genes (tDNAs) serve a variety of other critical cellular functions. For example, tRNAs and other Pol III transcripts can be cleaved to yield small RNAs with potent regulatory activities. Furthermore, from yeast to mammals, active tDNAs and related “extra-TFIIIC” (ETC) loci provide the DNA scaffolds for the most ancient known mechanism of three-dimensional chromatin architecture. Here we identify the ZSCAN5 TF family - including mammalian ZSCAN5B and its primate-specific paralogs - as proteins that occupy mammalian Pol III promoters and ETC sites. We show that ZSCAN5B binds with high specificity to a conserved subset of Pol III genes in human and mouse. Furthermore, primate-specific ZSCAN5A and ZSCAN5D also bind Pol III genes, although ZSCAN5D preferentially localizes to MIR SINE- and LINE2-associated ETC sites. ZSCAN5 genes are expressed in proliferating cell populations and are cell-cycle regulated, and siRNA knockdown experiments suggested a cooperative role in regulation of mitotic progression. Consistent with this prediction, ZSCAN5A knockdown led to increasing numbers of cells in mitosis and the appearance of cells. Together, these data implicate the role of ZSCAN5 genes in regulation of Pol III genes and nearby Pol II loci, ultimately influencing cell cycle progression and differentiation in a variety of tissues.
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Affiliation(s)
- Younguk Sun
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Huimin Zhang
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Majid Kazemian
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Laboratory of Molecular Immunology and the Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Joseph M Troy
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Illinois Informatics Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christopher Seward
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Xiaochen Lu
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Lisa Stubbs
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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7
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Roy K, Chanfreau GF. A global function for transcription factors in assisting RNA polymerase II termination. Transcription 2017; 9:41-46. [PMID: 29106321 DOI: 10.1080/21541264.2017.1300121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The role of transcription factors (TFs) on nucleosome positioning, RNA polymerase recruitment, and transcription initiation has been extensively characterized. Here, we propose that a subset of TFs such as Reb1, Abf1, Rap1, and TFIIIB also serve a major function in partitioning transcription units by assisting the Nrd1p-Nab3p-Sen1p Pol II termination pathway.
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Affiliation(s)
- Kevin Roy
- a Department of Chemistry and Biochemistry and the Molecular Biology Institute , University of California Los Angeles , CA , USA
| | - Guillaume F Chanfreau
- a Department of Chemistry and Biochemistry and the Molecular Biology Institute , University of California Los Angeles , CA , USA
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8
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Helbo AS, Lay FD, Jones PA, Liang G, Grønbæk K. Nucleosome Positioning and NDR Structure at RNA Polymerase III Promoters. Sci Rep 2017; 7:41947. [PMID: 28176797 PMCID: PMC5296907 DOI: 10.1038/srep41947] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 01/03/2017] [Indexed: 12/20/2022] Open
Abstract
Chromatin is structurally involved in the transcriptional regulation of all genes. While the nucleosome positioning at RNA polymerase II (pol II) promoters has been extensively studied, less is known about the chromatin structure at pol III promoters in human cells. We use a high-resolution analysis to show substantial differences in chromatin structure of pol II and pol III promoters, and between subtypes of pol III genes. Notably, the nucleosome depleted region at the transcription start site of pol III genes extends past the termination sequences, resulting in nucleosome free gene bodies. The +1 nucleosome is located further downstream than at pol II genes and furthermore displays weak positioning. The variable position of the +1 location is seen not only within individual cell populations and between cell types, but also between different pol III promoter subtypes, suggesting that the +1 nucleosome may be involved in the transcriptional regulation of pol III genes. We find that expression and DNA methylation patterns correlate with distinct accessibility patterns, where DNA methylation associates with the silencing and inaccessibility at promoters. Taken together, this study provides the first high-resolution map of nucleosome positioning and occupancy at human pol III promoters at specific loci and genome wide.
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Affiliation(s)
- Alexandra Søgaard Helbo
- Department of Hematology, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Fides D Lay
- Department of Urology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, 90089, USA
| | - Peter A Jones
- Department of Urology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, 90089, USA.,Van Andel Research Institute, Grand Rapids, 49503, USA
| | - Gangning Liang
- Department of Urology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, 90089, USA
| | - Kirsten Grønbæk
- Department of Hematology, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, 2100, Denmark
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9
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Wang Q, Donze D. Transcription factor Reb1 is required for proper transcriptional start site usage at the divergently transcribed TFC6-ESC2 locus in Saccharomyces cerevisiae. Gene 2016; 594:108-116. [PMID: 27601258 DOI: 10.1016/j.gene.2016.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/15/2016] [Accepted: 09/02/2016] [Indexed: 11/25/2022]
Abstract
Eukaryotic promoters generally contain nucleosome depleted regions near their transcription start sites. In the model organism Saccharomyces cerevisiae, these regions are adjacent to binding sites for general regulatory transcription factors, and the Reb1 protein is commonly bound to promoter DNA near such regions. The yeast TFC6 promoter is a unique RNA polymerase II promoter in that it is autoregulated by its own gene product Tfc6p, which is part of the RNA polymerase III transcription factor complex TFIIIC. We previously demonstrated that mutation of a potential Reb1 binding site adjacent to the TFIIIC binding site in the TFC6 promoter modestly reduces transcript levels, but leads to a severe decrease in Tfc6 protein levels due to an upstream shift in the TFC6 transcription start site. Here we confirm that Reb1p indeed binds to the TFC6 promoter, and is important for proper transcription start site selection and protein expression. Interestingly, loss of Reb1p association at this site has a similar effect on the adjacent divergently transcribed ESC2 promoter, resulting in a significant increase of 5'-extended ESC2 transcripts and reduction of Esc2 protein levels. This altered divergent transcription may be the result of changes in nucleosome positioning at this locus in the absence of Reb1p binding. We speculate that an important function of general regulatory factors such as Reb1p is to establish and maintain proper transcription start sites at promoters, and that when binding of such factors is compromised, resulting effects on mRNA translation may be an underappreciated aspect of gene regulation studies.
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Affiliation(s)
- Qing Wang
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, United States
| | - David Donze
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, United States.
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10
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Roy K, Gabunilas J, Gillespie A, Ngo D, Chanfreau GF. Common genomic elements promote transcriptional and DNA replication roadblocks. Genome Res 2016; 26:1363-1375. [PMID: 27540088 PMCID: PMC5052057 DOI: 10.1101/gr.204776.116] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 08/18/2016] [Indexed: 11/25/2022]
Abstract
RNA polymerase II (Pol II) transcription termination by the Nrd1p-Nab3p-Sen1p (NNS) pathway is critical for the production of stable noncoding RNAs and the control of pervasive transcription in Saccharomyces cerevisiae. To uncover determinants of NNS termination, we mapped the 3′-ends of NNS-terminated transcripts genome-wide. We found that nucleosomes and specific DNA-binding proteins, including the general regulatory factors (GRFs) Reb1p, Rap1p, and Abf1p, and Pol III transcription factors enhance the efficiency of NNS termination by physically blocking Pol II progression. The same DNA-bound factors that promote NNS termination were shown previously to define the 3′-ends of Okazaki fragments synthesized by Pol δ during DNA replication. Reduced binding of these factors results in defective NNS termination and Pol II readthrough. Furthermore, inactivating NNS enables Pol II elongation through these roadblocks, demonstrating that effective Pol II termination depends on a synergy between the NNS machinery and obstacles in chromatin. Consistent with this finding, loci exhibiting Pol II readthrough at GRF binding sites are depleted for upstream NNS signals. Overall, these results underscore how RNA termination signals influence the behavior of Pol II at chromatin obstacles, and establish that common genomic elements define boundaries for both DNA and RNA synthesis machineries.
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Affiliation(s)
- Kevin Roy
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095-1570, USA
| | - Jason Gabunilas
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, USA
| | - Abigail Gillespie
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, USA
| | - Duy Ngo
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, USA
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095-1570, USA
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