1
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Wu J, Chen W, Ge S, Liu X, Shan J, Zhang M, Su Y, Liu Y. ILP1 and NTR1 affect the stability of U6 snRNA during spliceosome complex disassembly in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 347:112199. [PMID: 39038708 DOI: 10.1016/j.plantsci.2024.112199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 07/16/2024] [Accepted: 07/18/2024] [Indexed: 07/24/2024]
Abstract
U6 snRNA is one of the uridine-rich non-coding RNAs, abundant and stable in various cells, function as core particles in the intron-lariat spliceosome (ILS) complex. The Increased Level of Polyploidy1-1D (ILP1) and NTC-related protein 1 (NTR1), two conserved disassembly factors of the ILS complex, facilitates the disintegration of the ILS complex after completing intron splicing. The functional impairment of ILP1 and NTR1 lead to increased U6 levels, while other snRNAs comprising the ILS complex remained unaffected. We revealed that ILP1 and NTR1 had no impact on the transcription, 3' end phosphate structure or oligo(U) tail of U6 snRNA. Moreover, we uncovered that the mutation of ILP1 and NTR1 resulted in the accumulation of ILS complexes, impeding the dissociation of U6 from splicing factors, leading to an extended half-life of U6 and ultimately causing an elevation in U6 snRNA levels. Our findings broaden the understanding of the functions of ILS disassembly factors ILP1 and NTR1, and providing insights into the dynamic disassembly between U6 and ILS.
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Affiliation(s)
- Jiaming Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.
| | - Wei Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.
| | - Shengchao Ge
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.
| | - Xueliang Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.
| | - Junling Shan
- Department of basic medicine, Guangxi Medical University of Nursing College, Nanning, Guangxi 530021, China.
| | - Meishan Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.
| | - Yuan Su
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.
| | - Yunfeng Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.
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2
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van Breugel ME, Gerber A, van Leeuwen F. The choreography of chromatin in RNA polymerase III regulation. Biochem Soc Trans 2024; 52:1173-1189. [PMID: 38666598 DOI: 10.1042/bst20230770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 06/27/2024]
Abstract
Regulation of eukaryotic gene expression involves a dynamic interplay between the core transcriptional machinery, transcription factors, and chromatin organization and modification. While this applies to transcription by all RNA polymerase complexes, RNA polymerase III (RNAPIII) seems to be atypical with respect to its mechanisms of regulation. One distinctive feature of most RNAPIII transcribed genes is that they are devoid of nucleosomes, which relates to the high levels of transcription. Moreover, most of the regulatory sequences are not outside but within the transcribed open chromatin regions. Yet, several lines of evidence suggest that chromatin factors affect RNAPIII dynamics and activity and that gene sequence alone does not explain the observed regulation of RNAPIII. Here we discuss the role of chromatin modification and organization of RNAPIII transcribed genes and how they interact with the core transcriptional RNAPIII machinery and regulatory DNA elements in and around the transcribed genes.
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Affiliation(s)
- Maria Elize van Breugel
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, The Netherlands
| | - Alan Gerber
- Department of Neurosurgery, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
- Cancer Center Amsterdam, Cancer Biology, Amsterdam 1081HV, The Netherlands
| | - Fred van Leeuwen
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, The Netherlands
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands
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3
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Struhl K. Non-canonical functions of enhancers: regulation of RNA polymerase III transcription, DNA replication, and V(D)J recombination. Trends Genet 2024; 40:471-479. [PMID: 38643034 PMCID: PMC11152991 DOI: 10.1016/j.tig.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/02/2024] [Indexed: 04/22/2024]
Abstract
Enhancers are the key regulators of other DNA-based processes by virtue of their unique ability to generate nucleosome-depleted regions in a highly regulated manner. Enhancers regulate cell-type-specific transcription of tRNA genes by RNA polymerase III (Pol III). They are also responsible for the binding of the origin replication complex (ORC) to DNA replication origins, thereby regulating origin utilization, replication timing, and replication-dependent chromosome breaks. Additionally, enhancers regulate V(D)J recombination by increasing access of the recombination-activating gene (RAG) recombinase to target sites and by generating non-coding enhancer RNAs and localized regions of trimethylated histone H3-K4 recognized by the RAG2 PHD domain. Thus, enhancers represent the first step in decoding the genome, and hence they regulate biological processes that, unlike RNA polymerase II (Pol II) transcription, do not have dedicated regulatory proteins.
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Affiliation(s)
- Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
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4
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Kitamura Y, Namekawa SH. Epigenetic priming in the male germline. Curr Opin Genet Dev 2024; 86:102190. [PMID: 38608568 PMCID: PMC11162906 DOI: 10.1016/j.gde.2024.102190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/29/2024] [Accepted: 03/12/2024] [Indexed: 04/14/2024]
Abstract
Epigenetic priming presets chromatin states that allow the rapid induction of gene expression programs in response to differentiation cues. In the germline, it provides the blueprint for sexually dimorphic unidirectional differentiation. In this review, we focus on epigenetic priming in the mammalian male germline and discuss how cellular memories are regulated and inherited to the next generation. During spermatogenesis, epigenetic priming predetermines cellular memories that ensure the lifelong maintenance of spermatogonial stem cells and their subsequent commitment to meiosis and to the production of haploid sperm. The paternal chromatin state is also essential for the recovery of totipotency after fertilization and contributes to paternal epigenetic inheritance. Thus, epigenetic priming establishes stable but reversible chromatin states during spermatogenesis and enables epigenetic inheritance and reprogramming in the next generation.
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Affiliation(s)
- Yuka Kitamura
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
| | - Satoshi H Namekawa
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA.
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5
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Yu X, Xu J. TWIST1 Drives Cytotoxic CD8+ T-Cell Exhaustion through Transcriptional Activation of CD274 (PD-L1) Expression in Breast Cancer Cells. Cancers (Basel) 2024; 16:1973. [PMID: 38893094 PMCID: PMC11171171 DOI: 10.3390/cancers16111973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/15/2024] [Accepted: 05/18/2024] [Indexed: 06/21/2024] Open
Abstract
In breast cancer, epithelial-mesenchymal transition (EMT) is positively associated with programmed death ligand 1 (PD-L1) expression and immune escape, and TWIST1 silences ERα expression and induces EMT and cancer metastasis. However, how TWIST1 regulates PD-L1 and immune evasion is unknown. This study analyzed TWIST1 and PD-L1 expression in breast cancers, investigated the mechanism for TWIST1 to regulate PD-L1 transcription, and assessed the effects of TWIST1 and PD-L1 in cancer cells on cytotoxic CD8+ T cells. Interestingly, TWIST1 expression is correlated with high-level PD-L1 expression in ERα-negative breast cancer cells. The overexpression and knockdown of TWIST1 robustly upregulate and downregulate PD-L1 expression, respectively. TWIST1 binds to the PD-L1 promoter and recruits the TIP60 acetyltransferase complex in a BRD8-dependent manner to transcriptionally activate PD-L1 expression, which significantly accelerates the exhaustion and death of the cytotoxic CD8+ T cells. Accordingly, knockdown of TWIST1 or BRD8 or inhibition of PD-L1 significantly enhances the tumor antigen-specific CD8+ T cells to suppress the growth of breast cancer cells. These results demonstrate that TWIST1 directly induces PD-L1 expression in ERα-negative breast cancer cells to promote immune evasion. Targeting TWIST1, BRD8, and/or PD-L1 in ERα-negative breast cancer cells with TWIST1 expression may sensitize CD8+ T-cell-mediated immunotherapy.
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Affiliation(s)
- Xiaobin Yu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Jianming Xu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA;
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
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6
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Rey F, Esposito L, Maghraby E, Mauri A, Berardo C, Bonaventura E, Tonduti D, Carelli S, Cereda C. Role of epigenetics and alterations in RNA metabolism in leukodystrophies. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1854. [PMID: 38831585 DOI: 10.1002/wrna.1854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 06/05/2024]
Abstract
Leukodystrophies are a class of rare heterogeneous disorders which affect the white matter of the brain, ultimately leading to a disruption in brain development and a damaging effect on cognitive, motor and social-communicative development. These disorders present a great clinical heterogeneity, along with a phenotypic overlap and this could be partially due to contributions from environmental stimuli. It is in this context that there is a great need to investigate what other factors may contribute to both disease insurgence and phenotypical heterogeneity, and novel evidence are raising the attention toward the study of epigenetics and transcription mechanisms that can influence the disease phenotype beyond genetics. Modulation in the epigenetics machinery including histone modifications, DNA methylation and non-coding RNAs dysregulation, could be crucial players in the development of these disorders, and moreover an aberrant RNA maturation process has been linked to leukodystrophies. Here, we provide an overview of these mechanisms hoping to supply a closer step toward the analysis of leukodystrophies not only as genetically determined but also with an added level of complexity where epigenetic dysregulation is of key relevance. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNA RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Federica Rey
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Letizia Esposito
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Erika Maghraby
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
- Department of Biology and Biotechnology "L. Spallanzani" (DBB), University of Pavia, Pavia, Italy
| | - Alessia Mauri
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Clarissa Berardo
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Eleonora Bonaventura
- Unit of Pediatric Neurology, COALA Center for Diagnosis and Treatment of Leukodystrophies, V. Buzzi Children's Hospital, Milan, Italy
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Davide Tonduti
- Unit of Pediatric Neurology, COALA Center for Diagnosis and Treatment of Leukodystrophies, V. Buzzi Children's Hospital, Milan, Italy
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Stephana Carelli
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Cristina Cereda
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
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7
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Kapur M, Molumby MJ, Guzman C, Heinz S, Ackerman SL. Cell-type-specific expression of tRNAs in the brain regulates cellular homeostasis. Neuron 2024; 112:1397-1415.e6. [PMID: 38377989 PMCID: PMC11065635 DOI: 10.1016/j.neuron.2024.01.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/23/2023] [Accepted: 01/29/2024] [Indexed: 02/22/2024]
Abstract
Defects in tRNA biogenesis are associated with multiple neurological disorders, yet our understanding of these diseases has been hampered by an inability to determine tRNA expression in individual cell types within a complex tissue. Here, we developed a mouse model in which RNA polymerase III is conditionally epitope tagged in a Cre-dependent manner, allowing us to accurately profile tRNA expression in any cell type in vivo. We investigated tRNA expression in diverse nervous system cell types, revealing dramatic heterogeneity in the expression of tRNA genes between populations. We found that while maintenance of levels of tRNA isoacceptor families is critical for cellular homeostasis, neurons are differentially vulnerable to insults to distinct tRNA isoacceptor families. Cell-type-specific translatome analysis suggests that the balance between tRNA availability and codon demand may underlie such differential resilience. Our work provides a platform for investigating the complexities of mRNA translation and tRNA biology in the brain.
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Affiliation(s)
- Mridu Kapur
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA; The Howard Hughes Medical Institute
| | - Michael J Molumby
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA; The Howard Hughes Medical Institute
| | - Carlos Guzman
- Department of Medicine, Division of Endocrinology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, Bioinformatics & Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sven Heinz
- Department of Medicine, Division of Endocrinology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, Bioinformatics & Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan L Ackerman
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA; The Howard Hughes Medical Institute; Department of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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8
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Arimbasseri AG, Shukla A, Pradhan AK, Bhargava P. Increased histone acetylation is the signature of repressed state on the genes transcribed by RNA polymerase III. Gene 2024; 893:147958. [PMID: 37923095 DOI: 10.1016/j.gene.2023.147958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/27/2023] [Accepted: 10/31/2023] [Indexed: 11/07/2023]
Abstract
Several covalent modifications are found associated with the transcriptionally active chromatin regions constituted by the genes transcribed by RNA polymerase (pol) II. Pol III-transcribed genes code for the small, stable RNA species, which participate in many cellular processes, essential for survival. Pol III transcription is repressed under most of the stress conditions by its negative regulator Maf1. We found that most of the histone acetylations increase with starvation-induced repression on several genes transcribed by the yeast pol III. On one of these genes, SNR6 (coding for the U6snRNA), a strongly positioned nucleosome in the gene upstream region plays regulatory role under repression. On this nucleosome, the changes in H3K9 and H3K14 acetylations show different dynamics. During repression, acetylation levels on H3K9 show steady increase whereas H3K14 acetylation increases with a peak at 40 min after which levels reduce. Both the levels settle by 2 hr to a level higher than the active state, which revert to normal levels with nutrient repletion. The increase in H3 acetylations is seen in the mutants reported to show reduced SNR6 transcription but not in the maf1Δ cells. This increase on a regulatory nucleosome may be part of the signaling mechanisms, which prepare cells for the stress-related quick repression as well as reactivation. The contrasting association of the histone acetylations with pol II and pol III transcription may be an important consideration to make in research studies focused on drug developments targeting histone modifications.
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Affiliation(s)
| | - Ashutosh Shukla
- Centre for Cellular and Molecular Biology, (Council of Scientific and Industrial Research), Uppal Road, Tarnaka, Hyderabad 500007, India
| | - Ashis Kumar Pradhan
- Centre for Cellular and Molecular Biology, (Council of Scientific and Industrial Research), Uppal Road, Tarnaka, Hyderabad 500007, India
| | - Purnima Bhargava
- Centre for Cellular and Molecular Biology, (Council of Scientific and Industrial Research), Uppal Road, Tarnaka, Hyderabad 500007, India.
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9
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Gao L, Behrens A, Rodschinka G, Forcelloni S, Wani S, Strasser K, Nedialkova DD. Selective gene expression maintains human tRNA anticodon pools during differentiation. Nat Cell Biol 2024; 26:100-112. [PMID: 38191669 PMCID: PMC10791582 DOI: 10.1038/s41556-023-01317-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 11/16/2023] [Indexed: 01/10/2024]
Abstract
Transfer RNAs are essential for translating genetic information into proteins. The human genome contains hundreds of predicted tRNA genes, many in multiple copies. How their expression is regulated to control tRNA repertoires is unknown. Here we combined quantitative tRNA profiling and chromatin immunoprecipitation with sequencing to measure tRNA expression following the differentiation of human induced pluripotent stem cells into neuronal and cardiac cells. We find that tRNA transcript levels vary substantially, whereas tRNA anticodon pools, which govern decoding rates, are more stable among cell types. Mechanistically, RNA polymerase III transcribes a wide range of tRNA genes in human induced pluripotent stem cells but on differentiation becomes constrained to a subset we define as housekeeping tRNAs. This shift is mediated by decreased mTORC1 signalling, which activates the RNA polymerase III repressor MAF1. Our data explain how tRNA anticodon pools are buffered to maintain decoding speed across cell types and reveal that mTORC1 drives selective tRNA expression during differentiation.
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Affiliation(s)
- Lexi Gao
- Mechanisms of Protein Biogenesis, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Andrew Behrens
- Mechanisms of Protein Biogenesis, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Geraldine Rodschinka
- Mechanisms of Protein Biogenesis, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sergio Forcelloni
- Mechanisms of Protein Biogenesis, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sascha Wani
- Mechanisms of Protein Biogenesis, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Katrin Strasser
- Mechanisms of Protein Biogenesis, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Danny D Nedialkova
- Mechanisms of Protein Biogenesis, Max Planck Institute of Biochemistry, Martinsried, Germany.
- Department of Bioscience, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany.
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10
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Kitamura Y, Takahashi K, Maezawa S, Munakata Y, Sakashita A, Kaplan N, Namekawa SH. CTCF-mediated 3D chromatin predetermines the gene expression program in the male germline. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.30.569508. [PMID: 38076840 PMCID: PMC10705413 DOI: 10.1101/2023.11.30.569508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Spermatogenesis is a unidirectional differentiation process that generates haploid sperm, but how the gene expression program that directs this process is established is largely unknown. Here we determine the high-resolution 3D chromatin architecture of male germ cells during spermatogenesis and show that CTCF-mediated 3D chromatin predetermines the gene expression program required for spermatogenesis. In undifferentiated spermatogonia, CTCF-mediated chromatin contacts on autosomes pre-establish meiosis-specific super-enhancers (SE). These meiotic SE recruit the master transcription factor A-MYB in meiotic spermatocytes, which strengthens their 3D contacts and instructs a burst of meiotic gene expression. We also find that at the mitosis-to-meiosis transition, the germline-specific Polycomb protein SCML2 resolves chromatin loops that are specific to mitotic spermatogonia. Moreover, SCML2 and A-MYB establish the unique 3D chromatin organization of sex chromosomes during meiotic sex chromosome inactivation. We propose that CTCF-mediated 3D chromatin organization enforces epigenetic priming that directs unidirectional differentiation, thereby determining the cellular identity of the male germline.
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Affiliation(s)
- Yuka Kitamura
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, 95616, USA
| | - Kazuki Takahashi
- Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - So Maezawa
- Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, 45229, USA
- Faculty of Science and Technology, Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba, 281-8510, Japan
| | - Yasuhisa Munakata
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, 95616, USA
- Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Akihiko Sakashita
- Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, 45229, USA
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, 160-8582 Japan
| | - Noam Kaplan
- Department of Physiology, Biophysics & Systems Biology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Satoshi H. Namekawa
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, 95616, USA
- Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, 45229, USA
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11
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Huang J, Ji X. Never a dull enzyme, RNA polymerase II. Transcription 2023; 14:49-67. [PMID: 37132022 PMCID: PMC10353340 DOI: 10.1080/21541264.2023.2208023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/04/2023] Open
Abstract
RNA polymerase II (Pol II) is composed of 12 subunits that collaborate to synthesize mRNA within the nucleus. Pol II is widely recognized as a passive holoenzyme, with the molecular functions of its subunits largely ignored. Recent studies employing auxin-inducible degron (AID) and multi-omics techniques have revealed that the functional diversity of Pol II is achieved through the differential contributions of its subunits to various transcriptional and post-transcriptional processes. By regulating these processes in a coordinated manner through its subunits, Pol II can optimize its activity for diverse biological functions. Here, we review recent progress in understanding Pol II subunits and their dysregulation in diseases, Pol II heterogeneity, Pol II clusters and the regulatory roles of RNA polymerases.
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Affiliation(s)
- Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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12
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Pinzaru AM, Tavazoie SF. Transfer RNAs as dynamic and critical regulators of cancer progression. Nat Rev Cancer 2023; 23:746-761. [PMID: 37814109 DOI: 10.1038/s41568-023-00611-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/28/2023] [Indexed: 10/11/2023]
Abstract
Transfer RNAs (tRNAs) have been historically viewed as non-dynamic adaptors that decode the genetic code into proteins. Recent work has uncovered dynamic regulatory roles for these fascinating molecules. Advances in tRNA detection methods have revealed that specific tRNAs can become modulated upon DNA copy number and chromatin alterations and can also be perturbed by oncogenic signalling and transcriptional regulators in cancer cells or the tumour microenvironment. Such alterations in the levels of specific tRNAs have been shown to causally impact cancer progression, including metastasis. Moreover, sequencing methods have identified tRNA-derived small RNAs that influence various aspects of cancer progression, such as cell proliferation and invasion, and could serve as diagnostic and prognostic biomarkers or putative therapeutic targets in various cancers. Finally, there is accumulating evidence, including from genetic models, that specific tRNA synthetases - the enzymes responsible for charging tRNAs with amino acids - can either promote or suppress tumour formation. In this Review, we provide an overview of how deregulation of tRNAs influences cancer formation and progression.
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Affiliation(s)
- Alexandra M Pinzaru
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA.
| | - Sohail F Tavazoie
- Laboratory of Systems Cancer Biology, The Rockefeller University, New York, NY, USA.
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13
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Sachs P, Bergmaier P, Treutwein K, Mermoud JE. The Conserved Chromatin Remodeler SMARCAD1 Interacts with TFIIIC and Architectural Proteins in Human and Mouse. Genes (Basel) 2023; 14:1793. [PMID: 37761933 PMCID: PMC10530723 DOI: 10.3390/genes14091793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
In vertebrates, SMARCAD1 participates in transcriptional regulation, heterochromatin maintenance, DNA repair, and replication. The molecular basis underlying its involvement in these processes is not well understood. We identified the RNA polymerase III general transcription factor TFIIIC as an interaction partner of native SMARCAD1 in mouse and human models using endogenous co-immunoprecipitations. TFIIIC has dual functionality, acting as a general transcription factor and as a genome organizer separating chromatin domains. We found that its partnership with SMARCAD1 is conserved across different mammalian cell types, from somatic to pluripotent cells. Using purified proteins, we confirmed that their interaction is direct. A gene expression analysis suggested that SMARCAD1 is dispensable for TFIIIC function as an RNA polymerase III transcription factor in mouse ESCs. The distribution of TFIIIC and SMARCAD1 in the ESC genome is distinct, and unlike in yeast, SMARCAD1 is not enriched at active tRNA genes. Further analysis of SMARCAD1-binding partners in pluripotent and differentiated mammalian cells reveals that SMARCAD1 associates with several factors that have key regulatory roles in chromatin organization, such as cohesin, laminB, and DDX5. Together, our work suggests for the first time that the SMARCAD1 enzyme participates in genome organization in mammalian nuclei through interactions with architectural proteins.
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Affiliation(s)
- Parysatis Sachs
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
- CMC Development, R&D, Sanofi, 65926 Frankfurt, Germany
| | - Philipp Bergmaier
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
- Global Development Operations, R&D, Merck Healthcare, 64293 Darmstadt, Germany
| | - Katrin Treutwein
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
| | - Jacqueline E. Mermoud
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
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14
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Davyt M, Bharti N, Ignatova Z. Effect of mRNA/tRNA mutations on translation speed: Implications for human diseases. J Biol Chem 2023; 299:105089. [PMID: 37495112 PMCID: PMC10470029 DOI: 10.1016/j.jbc.2023.105089] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 07/28/2023] Open
Abstract
Recent discoveries establish tRNAs as central regulators of mRNA translation dynamics, and therefore cotranslational folding and function of the encoded protein. The tRNA pool, whose composition and abundance change in a cell- and tissue-dependent manner, is the main factor which determines mRNA translation velocity. In this review, we discuss a group of pathogenic mutations, in the coding sequences of either protein-coding genes or in tRNA genes, that alter mRNA translation dynamics. We also summarize advances in tRNA biology that have uncovered how variations in tRNA levels on account of genetic mutations affect protein folding and function, and thereby contribute to phenotypic diversity in clinical manifestations.
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Affiliation(s)
- Marcos Davyt
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Nikhil Bharti
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Zoya Ignatova
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany.
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15
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Tian K, Wang R, Huang J, Wang H, Ji X. Subcellular localization shapes the fate of RNA polymerase III. Cell Rep 2023; 42:112941. [PMID: 37556328 DOI: 10.1016/j.celrep.2023.112941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 08/11/2023] Open
Abstract
RNA polymerase III (Pol III) plays a vital role in transcription and as a viral-DNA sensor, but how it is assembled and distributed within cells remains poorly understood. Here, we show that Pol III is assembled with chaperones in the cytoplasm and forms transcription-dependent protein clusters upon transport into the nucleus. The largest subunit (RPC1) depletion through an auxin-inducible degron leads to rapid degradation and disassembly of Pol III complex in the nucleus and cytoplasm, respectively. This generates a pool of partially assembled Pol III intermediates, which can be rapidly mobilized into the nucleus upon the restoration of RPC1. Our study highlights the critical role of subcellular localization in determining Pol III's fate and provides insight into the dynamic regulation of nuclear Pol III levels and the origin of cytoplasmic Pol III complexes involved in mediating viral immunity.
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Affiliation(s)
- Kai Tian
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Rui Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Hui Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
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16
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Macvanin MT, Gluvic Z, Bajic V, Isenovic ER. Novel insights regarding the role of noncoding RNAs in diabetes. World J Diabetes 2023; 14:958-976. [PMID: 37547582 PMCID: PMC10401459 DOI: 10.4239/wjd.v14.i7.958] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/01/2023] [Accepted: 05/23/2023] [Indexed: 07/12/2023] Open
Abstract
Diabetes mellitus (DM) is a group of metabolic disorders defined by hyperglycemia induced by insulin resistance, inadequate insulin secretion, or excessive glucagon secretion. In 2021, the global prevalence of diabetes is anticipated to be 10.7% (537 million people). Noncoding RNAs (ncRNAs) appear to have an important role in the initiation and progression of DM, according to a growing body of research. The two major groups of ncRNAs implicated in diabetic disorders are miRNAs and long noncoding RNAs. miRNAs are single-stranded, short (17–25 nucleotides), ncRNAs that influence gene expression at the post-transcriptional level. Because DM has reached epidemic proportions worldwide, it appears that novel diagnostic and therapeutic strategies are required to identify and treat complications associated with these diseases efficiently. miRNAs are gaining attention as biomarkers for DM diagnosis and potential treatment due to their function in maintaining physiological homeostasis via gene expression regulation. In this review, we address the issue of the gradually expanding global prevalence of DM by presenting a complete and up-to-date synopsis of various regulatory miRNAs involved in these disorders. We hope this review will spark discussion about ncRNAs as prognostic biomarkers and therapeutic tools for DM. We examine and synthesize recent research that used novel, high-throughput technologies to uncover ncRNAs involved in DM, necessitating a systematic approach to examining and summarizing their roles and possible diagnostic and therapeutic uses.
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Affiliation(s)
- Mirjana T Macvanin
- Department of Radiobiology and Molecular Genetics, Vinča Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade 11000, Serbia
| | - Zoran Gluvic
- Department of Endocrinology and Diabetes, Clinic for Internal Medicine, Zemun Clinical Hospital, School of Medicine, University of Belgrade, Belgrade 11000, Serbia
| | - Vladan Bajic
- Department of Radiobiology and Molecular Genetics, Vinča Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade 11000, Serbia
| | - Esma R Isenovic
- Department of Radiobiology and Molecular Genetics, Vinča Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade 11000, Serbia
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17
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Butterfield SP, Sizer RE, Rand E, White RJ. Selection of tRNA Genes in Human Breast Tumours Varies Substantially between Individuals. Cancers (Basel) 2023; 15:3576. [PMID: 37509247 PMCID: PMC10377016 DOI: 10.3390/cancers15143576] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/07/2023] [Accepted: 07/09/2023] [Indexed: 07/30/2023] Open
Abstract
Abnormally elevated expression of tRNA is a common feature of breast tumours. Rather than a uniform increase in all tRNAs, some are deregulated more strongly than others. Elevation of particular tRNAs has been associated with poor prognosis for patients, and experimental models have demonstrated the ability of some tRNAs to promote proliferation or metastasis. Each tRNA isoacceptor is encoded redundantly by multiple genes, which are commonly dispersed across several chromosomes. An unanswered question is whether the consistently high expression of a tRNA in a cancer type reflects the consistent activation of the same members of a gene family, or whether different family members are activated from one patient to the next. To address this question, we interrogated ChIP-seq data to determine which tRNA genes were active in individual breast tumours. This revealed that distinct sets of tRNA genes become activated in individual cancers, whereas there is much less variation in the expression patterns of families. Several pathways have been described that are likely to contribute to increases in tRNA gene transcription in breast tumours, but none of these can adequately explain the observed variation in the choice of genes between tumours. Current models may therefore lack at least one level of regulation.
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Affiliation(s)
| | - Rebecca E Sizer
- Department of Biology, University of York, York YO10 5DD, UK
| | - Emma Rand
- Department of Biology, University of York, York YO10 5DD, UK
| | - Robert J White
- Department of Biology, University of York, York YO10 5DD, UK
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18
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Yague-Sanz C, Migeot V, Larochelle M, Bachand F, Wéry M, Morillon A, Hermand D. Chromatin remodeling by Pol II primes efficient Pol III transcription. Nat Commun 2023; 14:3587. [PMID: 37328480 PMCID: PMC10276017 DOI: 10.1038/s41467-023-39387-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 06/09/2023] [Indexed: 06/18/2023] Open
Abstract
The packaging of the genetic material into chromatin imposes the remodeling of this barrier to allow efficient transcription. RNA polymerase II activity is coupled with several histone modification complexes that enforce remodeling. How RNA polymerase III (Pol III) counteracts the inhibitory effect of chromatin is unknown. We report here a mechanism where RNA Polymerase II (Pol II) transcription is required to prime and maintain nucleosome depletion at Pol III loci and contributes to efficient Pol III recruitment upon re-initiation of growth from stationary phase in Fission yeast. The Pcr1 transcription factor participates in the recruitment of Pol II, which affects local histone occupancy through the associated SAGA complex and a Pol II phospho-S2 CTD / Mst2 pathway. These data expand the central role of Pol II in gene expression beyond mRNA synthesis.
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Affiliation(s)
- Carlo Yague-Sanz
- URPHYM-GEMO, The University of Namur, rue de Bruxelles, 61, Namur, 5000, Belgium
| | - Valérie Migeot
- URPHYM-GEMO, The University of Namur, rue de Bruxelles, 61, Namur, 5000, Belgium
| | - Marc Larochelle
- RNA Group, Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - François Bachand
- RNA Group, Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - Maxime Wéry
- ncRNA, Epigenetic and Genome Fluidity, Institut Curie, PSL Research University, Université Pierre et Marie Curie, CNRS UMR 3244, Paris, France
| | - Antonin Morillon
- ncRNA, Epigenetic and Genome Fluidity, Institut Curie, PSL Research University, Université Pierre et Marie Curie, CNRS UMR 3244, Paris, France
| | - Damien Hermand
- URPHYM-GEMO, The University of Namur, rue de Bruxelles, 61, Namur, 5000, Belgium.
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19
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Jiang Y, Huang J, Tian K, Yi X, Zheng H, Zhu Y, Guo T, Ji X. Cross-regulome profiling of RNA polymerases highlights the regulatory role of polymerase III on mRNA transcription by maintaining local chromatin architecture. Genome Biol 2022; 23:246. [PMID: 36443871 PMCID: PMC9703767 DOI: 10.1186/s13059-022-02812-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 11/07/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Mammalian cells have three types of RNA polymerases (Pols), Pol I, II, and III. However, the extent to which these polymerases are cross-regulated and the underlying mechanisms remain unclear. RESULTS We employ genome-wide profiling after acute depletion of Pol I, Pol II, or Pol III to assess cross-regulatory effects between these Pols. We find that these enzymes mainly affect the transcription of their own target genes, while certain genes are transcribed by the other polymerases. Importantly, the most active type of crosstalk is exemplified by the fact that Pol III depletion affects Pol II transcription. Pol II genes with transcription changes upon Pol III depletion are enriched in diverse cellular functions, and Pol III binding sites are found near their promoters. However, these Pol III binding sites do not correspond to transfer RNAs. Moreover, we demonstrate that Pol III regulates Pol II transcription and chromatin binding of the facilitates chromatin transcription (FACT) complex to alter local chromatin structures, which in turn affects the Pol II transcription rate. CONCLUSIONS Our results support a model suggesting that RNA polymerases show cross-regulatory effects: Pol III affects local chromatin structures and the FACT-Pol II axis to regulate the Pol II transcription rate at certain gene loci. This study provides a new perspective for understanding the dysregulation of Pol III in various tissues affected by developmental diseases.
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Affiliation(s)
- Yongpeng Jiang
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Jie Huang
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Kai Tian
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Xiao Yi
- grid.494629.40000 0004 8008 9315Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,grid.494629.40000 0004 8008 9315Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,Westlake Omics (Hangzhou) Biotechnology Co., Ltd, Hangzhou, 310024 China
| | - Haonan Zheng
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Yi Zhu
- grid.494629.40000 0004 8008 9315Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,grid.494629.40000 0004 8008 9315Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,Westlake Omics (Hangzhou) Biotechnology Co., Ltd, Hangzhou, 310024 China
| | - Tiannan Guo
- grid.494629.40000 0004 8008 9315Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,grid.494629.40000 0004 8008 9315Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,Westlake Omics (Hangzhou) Biotechnology Co., Ltd, Hangzhou, 310024 China
| | - Xiong Ji
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
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20
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Geng K, Merino LG, Wedemann L, Martens A, Sobota M, Sanchez YP, Søndergaard JN, White RJ, Kutter C. Target-enriched nanopore sequencing and de novo assembly reveals co-occurrences of complex on-target genomic rearrangements induced by CRISPR-Cas9 in human cells. Genome Res 2022; 32:1876-1891. [PMID: 36180232 PMCID: PMC9712622 DOI: 10.1101/gr.276901.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/19/2022] [Indexed: 11/24/2022]
Abstract
The CRISPR-Cas9 system is widely used to permanently delete genomic regions via dual guide RNAs. Genomic rearrangements induced by CRISPR-Cas9 can occur, but continuous technical developments make it possible to characterize complex on-target effects. We combined an innovative droplet-based target enrichment approach with long-read sequencing and coupled it to a customized de novo sequence assembly. This approach enabled us to dissect the sequence content at kilobase scale within an on-target genomic locus. We here describe extensive genomic disruptions by Cas9, involving the allelic co-occurrence of a genomic duplication and inversion of the target region, as well as integrations of exogenous DNA and clustered interchromosomal DNA fragment rearrangements. Furthermore, we found that these genomic alterations led to functional aberrant DNA fragments and can alter cell proliferation. Our findings broaden the consequential spectrum of the Cas9 deletion system, reinforce the necessity of meticulous genomic validations, and introduce a data-driven workflow enabling detailed dissection of the on-target sequence content with superior resolution.
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Affiliation(s)
- Keyi Geng
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Lara G Merino
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Linda Wedemann
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Aniek Martens
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Małgorzata Sobota
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Yerma P Sanchez
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Jonas Nørskov Søndergaard
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Robert J White
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Claudia Kutter
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
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21
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Vabret N, Najburg V, Solovyov A, Gopal R, McClain C, Šulc P, Balan S, Rahou Y, Beauclair G, Chazal M, Varet H, Legendre R, Sismeiro O, Sanchez David RY, Chauveau L, Jouvenet N, Markowitz M, van der Werf S, Schwartz O, Tangy F, Bhardwaj N, Greenbaum BD, Komarova AV. Y RNAs are conserved endogenous RIG-I ligands across RNA virus infection and are targeted by HIV-1. iScience 2022; 25:104599. [PMID: 35789859 PMCID: PMC9250025 DOI: 10.1016/j.isci.2022.104599] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/01/2022] [Accepted: 06/07/2022] [Indexed: 11/18/2022] Open
Abstract
Pattern recognition receptors (PRRs) protect against microbial invasion by detecting specific molecular patterns found in pathogens and initiating an immune response. Although microbial-derived PRR ligands have been extensively characterized, the contribution and relevance of endogenous ligands to PRR activation remains overlooked. Here, we characterize the landscape of endogenous ligands that engage RIG-I-like receptors (RLRs) upon infection by different RNA viruses. In each infection, several RNAs transcribed by RNA polymerase III (Pol3) specifically engaged RLRs, particularly the family of Y RNAs. Sensing of Y RNAs was dependent on their mimicking of viral secondary structure and their 5'-triphosphate extremity. Further, we found that HIV-1 triggered a VPR-dependent downregulation of RNA triphosphatase DUSP11 in vitro and in vivo, inducing a transcriptome-wide change of cellular RNA 5'-triphosphorylation that licenses Y RNA immunogenicity. Overall, our work uncovers the contribution of endogenous RNAs to antiviral immunity and demonstrates the importance of this pathway in HIV-1 infection.
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Affiliation(s)
- Nicolas Vabret
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Valérie Najburg
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Alexander Solovyov
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ramya Gopal
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Christopher McClain
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Petr Šulc
- Center for Molecular Design and Biomimetics at the Biodesign Institute and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Sreekumar Balan
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yannis Rahou
- Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Guillaume Beauclair
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Maxime Chazal
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Hugo Varet
- Transcriptome and EpiGenome Platform, BioMics, Center of Innovation and Technological Research, Institut Pasteur, Université de Paris, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
- Hub Informatique et Biostatistique, Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI, USR 3756 IP-CNRS), Institut Pasteur, Université de Paris, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Rachel Legendre
- Transcriptome and EpiGenome Platform, BioMics, Center of Innovation and Technological Research, Institut Pasteur, Université de Paris, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
- Hub Informatique et Biostatistique, Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI, USR 3756 IP-CNRS), Institut Pasteur, Université de Paris, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Odile Sismeiro
- Transcriptome and EpiGenome Platform, BioMics, Center of Innovation and Technological Research, Institut Pasteur, Université de Paris, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Raul Y. Sanchez David
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Lise Chauveau
- Virus & Immunity Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Nolwenn Jouvenet
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Martin Markowitz
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, NY, USA
| | - Sylvie van der Werf
- Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Olivier Schwartz
- Virus & Immunity Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Frédéric Tangy
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Nina Bhardwaj
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Extra-mural Member, Parker Institute of Cancer Immunotherapy, USA
| | - Benjamin D. Greenbaum
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Physiology, Biophysics, & Systems Biology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Anastassia V. Komarova
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
- Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
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22
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Van Bortle K, Marciano DP, Liu Q, Chou T, Lipchik AM, Gollapudi S, Geller BS, Monte E, Kamakaka RT, Snyder MP. A cancer-associated RNA polymerase III identity drives robust transcription and expression of snaR-A noncoding RNA. Nat Commun 2022; 13:3007. [PMID: 35637192 PMCID: PMC9151912 DOI: 10.1038/s41467-022-30323-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 04/13/2022] [Indexed: 11/09/2022] Open
Abstract
RNA polymerase III (Pol III) includes two alternate isoforms, defined by mutually exclusive incorporation of subunit POLR3G (RPC7α) or POLR3GL (RPC7β), in mammals. The contributions of POLR3G and POLR3GL to transcription potential has remained poorly defined. Here, we discover that loss of subunit POLR3G is accompanied by a restricted repertoire of genes transcribed by Pol III. Particularly sensitive is snaR-A, a small noncoding RNA implicated in cancer proliferation and metastasis. Analysis of Pol III isoform biases and downstream chromatin features identifies loss of POLR3G and snaR-A during differentiation, and conversely, re-establishment of POLR3G gene expression and SNAR-A gene features in cancer contexts. Our results support a model in which Pol III identity functions as an important transcriptional regulatory mechanism. Upregulation of POLR3G, which is driven by MYC, identifies a subgroup of patients with unfavorable survival outcomes in specific cancers, further implicating the POLR3G-enhanced transcription repertoire as a potential disease factor. RNA polymerase III changes its subunit composition during mammalian development. Here the authors report that loss of subunit POLR3G, which re-emerges in cancer, promotes expression of small NF90-associated RNA (snaR-A), a noncoding RNA implicated in cell proliferation and metastasis.
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23
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Sizer RE, Chahid N, Butterfield SP, Donze D, Bryant NJ, White RJ. TFIIIC-based chromatin insulators through eukaryotic evolution. Gene X 2022; 835:146533. [PMID: 35623477 DOI: 10.1016/j.gene.2022.146533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 04/19/2022] [Accepted: 04/29/2022] [Indexed: 11/04/2022] Open
Abstract
Eukaryotic chromosomes are divided into domains with distinct structural and functional properties, such as differing levels of chromatin compaction and gene transcription. Domains of relatively compact chromatin and minimal transcription are termed heterochromatic, whereas euchromatin is more open and actively transcribed. Insulators separate these domains and maintain their distinct features. Disruption of insulators can cause diseases such as cancer. Many insulators contain tRNA genes (tDNAs), examples of which have been shown to block the spread of activating or silencing activities. This characteristic of specific tDNAs is conserved through evolution, such that human tDNAs can serve as barriers to the spread of silencing in fission yeast. Here we demonstrate that tDNAs from the methylotrophic fungus Pichia pastoris can function effectively as insulators in distantly-related budding yeast. Key to the function of tDNAs as insulators is TFIIIC, a transcription factor that is also required for their expression. TFIIIC binds additional loci besides tDNAs, some of which have insulator activity. Although the mechanistic basis of TFIIIC-based insulation has been studied extensively in yeast, it is largely uncharacterized in metazoa. Utilising publicly-available genome-wide ChIP-seq data, we consider the extent to which mechanisms conserved from yeast to man may suffice to allow efficient insulation by TFIIIC in the more challenging chromatin environments of metazoa and suggest features that may have been acquired during evolution to cope with new challenges. We demonstrate the widespread presence at human tDNAs of USF1, a transcription factor with well-established barrier activity in vertebrates. We predict that tDNA-based insulators in higher organisms have evolved through incorporation of modules, such as binding sites for factors like USF1 and CTCF that are absent from yeasts, thereby strengthening function and providing opportunities for regulation between cell types.
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Affiliation(s)
- Rebecca E Sizer
- Department of Biology, The University of York, York YO10 5DD, UK
| | - Nisreen Chahid
- Department of Biology, The University of York, York YO10 5DD, UK
| | | | - David Donze
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Nia J Bryant
- Department of Biology, The University of York, York YO10 5DD, UK
| | - Robert J White
- Department of Biology, The University of York, York YO10 5DD, UK.
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24
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Epigenetic regulation of human non-coding RNA gene transcription. Biochem Soc Trans 2022; 50:723-736. [PMID: 35285478 DOI: 10.1042/bst20210860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 12/12/2022]
Abstract
Recent investigations on the non-protein-coding transcriptome of human cells have revealed previously hidden layers of gene regulation relying on regulatory non-protein-coding (nc) RNAs, including the widespread ncRNA-dependent regulation of epigenetic chromatin states and of mRNA translation and stability. However, despite its centrality, the epigenetic regulation of ncRNA genes has received relatively little attention. In this mini-review, we attempt to provide a synthetic account of recent literature suggesting an unexpected complexity in chromatin-dependent regulation of ncRNA gene transcription by the three human nuclear RNA polymerases. Emerging common features, like the heterogeneity of chromatin states within ncRNA multigene families and their influence on 3D genome organization, point to unexplored issues whose investigation could lead to a better understanding of the whole human epigenomic network.
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25
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Wong CH, Li CH, Man Tong JH, Zheng D, He Q, Luo Z, Lou UK, Wang J, To KF, Chen Y. The Establishment of CDK9/ RNA PolII/H3K4me3/DNA Methylation Feedback Promotes HOTAIR Expression by RNA Elongation Enhancement in Cancer. Mol Ther 2022; 30:1597-1609. [PMID: 35121112 PMCID: PMC9077372 DOI: 10.1016/j.ymthe.2022.01.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 12/07/2021] [Accepted: 01/28/2022] [Indexed: 11/28/2022] Open
Abstract
Long non-coding RNA HOX Transcript Antisense RNA (HOTAIR) is overexpressed in multiple cancers with diverse genetic profiles. Importantly, since HOTAIR heavily contributes to cancer progression by promoting tumor growth and metastasis, HOTAIR becomes a potential target for cancer therapy. However, the underlying mechanism leading to HOTAIR deregulation is largely unexplored. Here, we performed a pan-cancer analysis using more than 4,200 samples and found that intragenic exon CpG island (Ex-CGI) was hypermethylated and was positively correlated to HOTAIR expression. Also, we revealed that Ex-CGI methylation promotes HOTAIR expression through enhancing the transcription elongation process. Furthermore, we linked up the aberrant intragenic tri-methylation on H3 at lysine 4 (H3K4me3) and Ex-CGI DNA methylation in promoting transcription elongation of HOTAIR. Targeting the oncogenic CDK7-CDK9-H3K4me3 axis downregulated HOTAIR expression and inhibited cell growth in many cancers. To our knowledge, this is the first time that a positive feedback loop that involved CDK9-mediated phosphorylation of RNA Polymerase II Serine 2 (RNA PolII Ser2), H3K4me3, and intragenic DNA methylation, which induced robust transcriptional elongation and heavily contributed to the upregulation of oncogenic lncRNA in cancer has been demonstrated. Targeting the oncogenic CDK7-CDK9-H3K4me3 axis could be a novel therapy in many cancers through inhibiting the HOTAIR expression.
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Affiliation(s)
- Chi Hin Wong
- A School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Chi Han Li
- A School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Joanna Hung Man Tong
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Duo Zheng
- Guangdong Provincial Key Laboratory of Regional Immunity and Diseases, Shenzhen University International Cancer Center, Department of Cell Biology and Genetics, School of Medicine, Shenzhen University, Shenzhen 518055, China
| | - Qifang He
- A School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Zhiyuan Luo
- A School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Ut Kei Lou
- A School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Jiatong Wang
- A School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Ka-Fai To
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yangchao Chen
- A School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong; Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518087, China.
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26
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Saponaro M. Transcription-Replication Coordination. Life (Basel) 2022; 12:108. [PMID: 35054503 PMCID: PMC8781949 DOI: 10.3390/life12010108] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/06/2022] [Accepted: 01/10/2022] [Indexed: 12/02/2022] Open
Abstract
Transcription and replication are the two most essential processes that a cell does with its DNA: they allow cells to express the genomic content that is required for their functions and to create a perfect copy of this genomic information to pass on to the daughter cells. Nevertheless, these two processes are in a constant ambivalent relationship. When transcription and replication occupy the same regions, there is the possibility of conflicts between transcription and replication as transcription can impair DNA replication progression leading to increased DNA damage. Nevertheless, DNA replication origins are preferentially located in open chromatin next to actively transcribed regions, meaning that the possibility of conflicts is potentially an accepted incident for cells. Data in the literature point both towards the existence or not of coordination between these two processes to avoid the danger of collisions. Several reviews have been published on transcription-replication conflicts, but we focus here on the most recent findings that relate to how these two processes are coordinated in eukaryotes, considering advantages and disadvantages from coordination, how likely conflicts are at any given time, and which are their potential hotspots in the genome.
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Affiliation(s)
- Marco Saponaro
- Transcription Associated Genome Instability Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
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27
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Zhang S, Shao Y, Li C. Characterization of Host lncRNAs in Response to Vibrio splendidus Infection and Function as Efficient miRNA Sponges in Sea Cucumber. Front Immunol 2021; 12:792040. [PMID: 34868083 PMCID: PMC8635200 DOI: 10.3389/fimmu.2021.792040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 10/29/2021] [Indexed: 11/28/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) have been reported to play critical roles during pathogen infection and innate immune response in mammals. Such observation inspired us to explore the expression profiles and functions of lncRNAs in invertebrates upon bacterial infection. Here, the lncRNAs of sea cucumber (Apostichopus japonicus) involved in Vibrio splendidus infection were characterized. RNA-seq obtained 2897 differentially expressed lncRNAs from Vibrio splendidus infected coelomocytes of sea cucumbers. The potential functions of the significant differentially expressed lncRNAs were related to immunity and metabolic process based on the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Moreover, we identify a lncRNA (XLOC_028509), which is downregulated with Vibrio splendidus challenged, further study indicated that XLOC_028509 adsorb miR-2008 and miR-31 as competing endogenous RNAs (ceRNAs) through base complementarity, which in turn decreased the amount of miRNAs (microRNAs) bound to the 3’UTRs (untranslated regions) of mRNAs to reduce their inhibition of target gene translation. These data demonstrated that the lncRNAs of invertebrates might be important regulators in pathogen-host interactions by sponging miRNAs.
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Affiliation(s)
- Siyuan Zhang
- State Key Laboratory for Quality and Safety of Agro-Products, Ningbo University, Ningbo, China.,Collaborative Innovation Center for Zhejiang Marine High-Efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Yina Shao
- State Key Laboratory for Quality and Safety of Agro-Products, Ningbo University, Ningbo, China.,Collaborative Innovation Center for Zhejiang Marine High-Efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Chenghua Li
- State Key Laboratory for Quality and Safety of Agro-Products, Ningbo University, Ningbo, China.,Collaborative Innovation Center for Zhejiang Marine High-Efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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28
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Yan B, Tzertzinis G, Schildkraut I, Ettwiller L. Comprehensive determination of transcription start sites derived from all RNA polymerases using ReCappable-seq. Genome Res 2021; 32:162-174. [PMID: 34815308 PMCID: PMC8744680 DOI: 10.1101/gr.275784.121] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 11/19/2021] [Indexed: 11/24/2022]
Abstract
Determination of eukaryotic transcription start sites (TSSs) has been based on methods that require the cap structure at the 5' end of transcripts derived from Pol II RNA polymerase. Consequently, these methods do not reveal TSSs derived from the other RNA polymerases that also play critical roles in various cell functions. To address this limitation, we developed ReCappable-seq, which comprehensively identifies TSS for both Pol II and non-Pol II transcripts at single-nucleotide resolution. The method relies on specific enzymatic exchange of 5' m7G caps and 5' triphosphates with a selectable tag. When applied to human transcriptomes, ReCappable-seq identifies Pol II TSSs that are in agreement with orthogonal methods such as CAGE. Additionally, ReCappable-seq reveals a rich landscape of TSSs associated with Pol III transcripts that have not previously been amenable to study at genome-wide scale. Novel TSS from non-Pol II transcription can be located in the nuclear and mitochondrial genomes. ReCappable-seq interrogates the regulatory landscape of coding and noncoding RNA concurrently and enables the classification of epigenetic profiles associated with Pol II and non-Pol II TSS.
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Affiliation(s)
- Bo Yan
- New England Biolabs Incorporated, Ipswich, Massachusetts 01938, USA
| | | | - Ira Schildkraut
- New England Biolabs Incorporated, Ipswich, Massachusetts 01938, USA
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29
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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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30
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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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31
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Ottenburghs J, Geng K, Suh A, Kutter C. Genome Size Reduction and Transposon Activity Impact tRNA Gene Diversity While Ensuring Translational Stability in Birds. Genome Biol Evol 2021; 13:6127176. [PMID: 33533905 PMCID: PMC8044555 DOI: 10.1093/gbe/evab016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
As a highly diverse vertebrate class, bird species have adapted to various ecological systems. How this phenotypic diversity can be explained genetically is intensively debated and is likely grounded in differences in the genome content. Larger and more complex genomes could allow for greater genetic regulation that results in more phenotypic variety. Surprisingly, avian genomes are much smaller compared to other vertebrates but contain as many protein-coding genes as other vertebrates. This supports the notion that the phenotypic diversity is largely determined by selection on non-coding gene sequences. Transfer RNAs (tRNAs) represent a group of non-coding genes. However, the characteristics of tRNA genes across bird genomes have remained largely unexplored. Here, we exhaustively investigated the evolution and functional consequences of these crucial translational regulators within bird species and across vertebrates. Our dense sampling of 55 avian genomes representing each bird order revealed an average of 169 tRNA genes with at least 31% being actively used. Unlike other vertebrates, avian tRNA genes are reduced in number and complexity but are still in line with vertebrate wobble pairing strategies and mutation-driven codon usage. Our detailed phylogenetic analyses further uncovered that new tRNA genes can emerge through multiplication by transposable elements. Together, this study provides the first comprehensive avian and cross-vertebrate tRNA gene analyses and demonstrates that tRNA gene evolution is flexible albeit constrained within functional boundaries of general mechanisms in protein translation.
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Affiliation(s)
- Jente Ottenburghs
- Department of Microbiology, Tumor and Cell Biology, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden.,Department of Ecology and Genetics, Evolutionary Biology Centre, Science for Life Laboratory, Uppsala University, Sweden
| | - Keyi Geng
- Department of Microbiology, Tumor and Cell Biology, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
| | - Alexander Suh
- Department of Ecology and Genetics, Evolutionary Biology Centre, Science for Life Laboratory, Uppsala University, Sweden
| | - Claudia Kutter
- Department of Microbiology, Tumor and Cell Biology, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
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32
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Wakamori M, Okabe K, Ura K, Funatsu T, Takinoue M, Umehara T. Quantification of the effect of site-specific histone acetylation on chromatin transcription rate. Nucleic Acids Res 2021; 48:12648-12659. [PMID: 33238306 PMCID: PMC7736822 DOI: 10.1093/nar/gkaa1050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 12/13/2022] Open
Abstract
Eukaryotic transcription is epigenetically regulated by chromatin structure and post-translational modifications (PTMs). For example, lysine acetylation in histone H4 is correlated with activation of RNA polymerase I-, II- and III-driven transcription from chromatin templates, which requires prior chromatin remodeling. However, quantitative understanding of the contribution of particular PTM states to the sequential steps of eukaryotic transcription has been hampered partially because reconstitution of a chromatin template with designed PTMs is difficult. In this study, we reconstituted a di-nucleosome with site-specifically acetylated or unmodified histone H4, which contained two copies of the Xenopus somatic 5S rRNA gene with addition of a unique sequence detectable by hybridization-assisted fluorescence correlation spectroscopy. Using a Xenopus oocyte nuclear extract, we analyzed the time course of accumulation of nascent 5S rRNA-derived transcripts generated on chromatin templates in vitro. Our mathematically described kinetic model and fitting analysis revealed that tetra-acetylation of histone H4 at K5/K8/K12/K16 increases the rate of transcriptionally competent chromatin formation ∼3-fold in comparison with the absence of acetylation. We provide a kinetic model for quantitative evaluation of the contribution of epigenetic modifications to chromatin transcription.
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Affiliation(s)
- Masatoshi Wakamori
- Laboratory for Epigenetics Drug Discovery, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Kohki Okabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.,PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Kiyoe Ura
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.,Graduate School of Science, Chiba University, Chiba, Chiba 263-8522, Japan
| | - Takashi Funatsu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masahiro Takinoue
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.,Department of Computer Science, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502, Japan
| | - Takashi Umehara
- Laboratory for Epigenetics Drug Discovery, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan.,PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
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33
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Abstract
Viral infection can dramatically change the gene expression landscape of the host cell, yet little is known regarding changes in noncoding gene transcription by RNA polymerase III (RNAPIII). Among these are transfer RNAs (tRNAs), which are fundamental in protein translation, yet whose gene regulatory features remain largely undefined in mammalian cells. Transfer RNAs (tRNAs) are transcribed by RNA polymerase III (RNAPIII) and play a central role in decoding our genome, yet their expression and noncanonical function remain understudied. Many DNA tumor viruses enhance the activity of RNAPIII, yet whether infection alters tRNA expression is largely unknown. Here, we present the first genome-wide analysis of how viral infection alters the tRNAome. Using a tRNA-specific sequencing method (DM-tRNA-seq), we find that the murine gammaherpesvirus MHV68 induces global changes in premature tRNA (pre-tRNA) expression, with 14% of tRNA genes upregulated more than 3-fold, indicating that differential tRNA gene induction is a characteristic of DNA virus infection. Elevated pre-tRNA expression corresponds to increased RNAPIII occupancy for the subset of tRNA genes tested; additionally, posttranscriptional mechanisms contribute to the accumulation of pre-tRNA species. We find increased abundance of tRNA fragments derived from pre-tRNAs upregulated by viral infection, suggesting that noncanonical tRNA cleavage is also affected. Furthermore, pre-tRNA accumulation, but not RNAPIII recruitment, requires gammaherpesvirus-induced degradation of host mRNAs by the virally encoded mRNA endonuclease muSOX. We hypothesize that depletion of pre-tRNA maturation or turnover machinery contributes to robust accumulation of full-length pre-tRNAs in infected cells. Collectively, these findings reveal pervasive changes to tRNA expression during DNA virus infection and highlight the potential of using viruses to explore tRNA biology.
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34
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Functions of paralogous RNA polymerase III subunits POLR3G and POLR3GL in mouse development. Proc Natl Acad Sci U S A 2020; 117:15702-15711. [PMID: 32576691 DOI: 10.1073/pnas.1922821117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Mammalian cells contain two isoforms of RNA polymerase III (Pol III) that differ in only a single subunit, with POLR3G in one form (Pol IIIα) and the related POLR3GL in the other form (Pol IIIβ). Previous research indicates that POLR3G and POLR3GL are differentially expressed, with POLR3G expression being highly enriched in embryonic stem cells (ESCs) and tumor cells relative to the ubiquitously expressed POLR3GL. To date, the functional differences between these two subunits remain largely unexplored, especially in vivo. Here, we show that POLR3G and POLR3GL containing Pol III complexes bind the same target genes and assume the same functions both in vitro and in vivo and, to a significant degree, can compensate for each other in vivo. Notably, an observed defect in the differentiation ability of POLR3G knockout ESCs can be rescued by exogenous expression of POLR3GL. Moreover, whereas POLR3G knockout mice die at a very early embryonic stage, POLR3GL knockout mice complete embryonic development without noticeable defects but die at about 3 wk after birth with signs of both general growth defects and potential cerebellum-related neuronal defects. The different phenotypes of the knockout mice likely reflect differential expression levels of POLR3G and POLR3GL across developmental stages and between tissues and insufficient amounts of total Pol III in vivo.
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35
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Gene-Specific Control of tRNA Expression by RNA Polymerase II. Mol Cell 2020; 78:765-778.e7. [PMID: 32298650 DOI: 10.1016/j.molcel.2020.03.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/12/2020] [Accepted: 03/13/2020] [Indexed: 12/20/2022]
Abstract
Increasing evidence suggests that tRNA levels are dynamically and specifically regulated in response to internal and external cues to modulate the cellular translational program. However, the molecular players and the mechanisms regulating the gene-specific expression of tRNAs are still unknown. Using an inducible auxin-degron system to rapidly deplete RPB1 (the largest subunit of RNA Pol II) in living cells, we identified Pol II as a direct gene-specific regulator of tRNA transcription. Our data suggest that Pol II transcription robustly interferes with Pol III function at specific tRNA genes. This activity was further found to be essential for MAF1-mediated repression of a large set of tRNA genes during serum starvation, indicating that repression of tRNA genes by Pol II is dynamically regulated. Hence, Pol II plays a direct and central role in the gene-specific regulation of tRNA expression.
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36
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Peng F, Zhou Y, Wang J, Guo B, Wei Y, Deng H, Wu Z, Zhang C, Shi K, Li Y, Wang X, Shore P, Zhao S, Deng W. The transcription factor Sp1 modulates RNA polymerase III gene transcription by controlling BRF1 and GTF3C2 expression in human cells. J Biol Chem 2020; 295:4617-4630. [PMID: 32115405 DOI: 10.1074/jbc.ra119.011555] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/16/2020] [Indexed: 01/10/2023] Open
Abstract
Specificity protein 1 (Sp1) is an important transcription factor implicated in numerous cellular processes. However, whether Sp1 is involved in the regulation of RNA polymerase III (Pol III)-directed gene transcription in human cells remains unknown. Here, we first show that filamin A (FLNA) represses Sp1 expression as well as expression of TFIIB-related factor 1 (BRF1) and general transcription factor III C subunit 2 (GTF3C2) in HeLa, 293T, and SaOS2 cell lines stably expressing FLNA-silencing shRNAs. Both BRF1 promoter 4 (BRF1P4) and GTF3C2 promoter 2 (GTF3C2P2) contain putative Sp1-binding sites, suggesting that Sp1 affects Pol III gene transcription by regulating BRF1 and GTF3C2 expression. We demonstrate that Sp1 knockdown inhibits Pol III gene transcription, BRF1 and GTF3C2 expression, and the proliferation of 293T and HeLa cells, whereas Sp1 overexpression enhances these activities. We obtained a comparable result in a cell line in which both FLNA and Sp1 were depleted. These results indicate that Sp1 is involved in the regulation of Pol III gene transcription independently of FLNA expression. Reporter gene assays showed that alteration of Sp1 expression affects BRF1P4 and GTF3C2P2 activation, suggesting that Sp1 modulates Pol III-mediated gene transcription by controlling BRF1 and GTF3C2 gene expression. Further analysis revealed that Sp1 interacts with and thereby promotes the occupancies of TATA box-binding protein, TFIIAα, and p300 at both BRF1P4 and GTF3C2P2. These findings indicate that Sp1 controls Pol III-directed transcription and shed light on how Sp1 regulates cancer cell proliferation.
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Affiliation(s)
- Feixia Peng
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Ying Zhou
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Juan Wang
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Baoqiang Guo
- Centre for Bioscience, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom
| | - Yun Wei
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Huan Deng
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Zihui Wu
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Cheng Zhang
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Kaituo Shi
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Yuan Li
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Xin Wang
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Paul Shore
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Shasha Zhao
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Wensheng Deng
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan 430065, China
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Transcription-independent TFIIIC-bound sites cluster near heterochromatin boundaries within lamina-associated domains in C. elegans. Epigenetics Chromatin 2020; 13:1. [PMID: 31918747 PMCID: PMC6950938 DOI: 10.1186/s13072-019-0325-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 12/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chromatin organization is central to precise control of gene expression. In various eukaryotic species, domains of pervasive cis-chromatin interactions demarcate functional domains of the genomes. In nematode Caenorhabditis elegans, however, pervasive chromatin contact domains are limited to the dosage-compensated sex chromosome, leaving the principle of C. elegans chromatin organization unclear. Transcription factor III C (TFIIIC) is a basal transcription factor complex for RNA polymerase III, and is implicated in chromatin organization. TFIIIC binding without RNA polymerase III co-occupancy, referred to as extra-TFIIIC binding, has been implicated in insulating active and inactive chromatin domains in yeasts, flies, and mammalian cells. Whether extra-TFIIIC sites are present and contribute to chromatin organization in C. elegans remains unknown. RESULTS We identified 504 TFIIIC-bound sites absent of RNA polymerase III and TATA-binding protein co-occupancy characteristic of extra-TFIIIC sites in C. elegans embryos. Extra-TFIIIC sites constituted half of all identified TFIIIC binding sites in the genome. Extra-TFIIIC sites formed dense clusters in cis. The clusters of extra-TFIIIC sites were highly over-represented within the distal arm domains of the autosomes that presented a high level of heterochromatin-associated histone H3K9 trimethylation (H3K9me3). Furthermore, extra-TFIIIC clusters were embedded in the lamina-associated domains. Despite the heterochromatin environment of extra-TFIIIC sites, the individual clusters of extra-TFIIIC sites were devoid of and resided near the individual H3K9me3-marked regions. CONCLUSION Clusters of extra-TFIIIC sites were pervasive in the arm domains of C. elegans autosomes, near the outer boundaries of H3K9me3-marked regions. Given the reported activity of extra-TFIIIC sites in heterochromatin insulation in yeasts, our observation raised the possibility that TFIIIC may also demarcate heterochromatin in C. elegans.
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38
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Petrie JL, Swan C, Ingram RM, Frame FM, Collins AT, Dumay-Odelot H, Teichmann M, Maitland NJ, White RJ. Effects on prostate cancer cells of targeting RNA polymerase III. Nucleic Acids Res 2019; 47:3937-3956. [PMID: 30820548 PMCID: PMC6486637 DOI: 10.1093/nar/gkz128] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/13/2019] [Accepted: 02/19/2019] [Indexed: 12/12/2022] Open
Abstract
RNA polymerase (pol) III occurs in two forms, containing either the POLR3G subunit or the related paralogue POLR3GL. Whereas POLR3GL is ubiquitous, POLR3G is enriched in undifferentiated cells. Depletion of POLR3G selectively triggers proliferative arrest and differentiation of prostate cancer cells, responses not elicited when POLR3GL is depleted. A small molecule pol III inhibitor can cause POLR3G depletion, induce similar differentiation and suppress proliferation and viability of cancer cells. This response involves control of the fate-determining factor NANOG by small RNAs derived from Alu short interspersed nuclear elements. Tumour initiating activity in vivo can be reduced by transient exposure to the pol III inhibitor. Untransformed prostate cells appear less sensitive than cancer cells to pol III depletion or inhibition, raising the possibility of a therapeutic window.
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Affiliation(s)
- John L Petrie
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Caroline Swan
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Richard M Ingram
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Fiona M Frame
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Anne T Collins
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Hélène Dumay-Odelot
- Université de Bordeaux, ARNA Laboratory, F-33076 Bordeaux, France INSERM, U1212 - CNRS UMR 5320, ARNA Laboratory, F-33000 Bordeaux, France
| | - Martin Teichmann
- Université de Bordeaux, ARNA Laboratory, F-33076 Bordeaux, France INSERM, U1212 - CNRS UMR 5320, ARNA Laboratory, F-33000 Bordeaux, France
| | - Norman J Maitland
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Robert J White
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
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39
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Yeast PAF1 complex counters the pol III accumulation and replication stress on the tRNA genes. Sci Rep 2019; 9:12892. [PMID: 31501524 PMCID: PMC6733944 DOI: 10.1038/s41598-019-49316-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 08/21/2019] [Indexed: 12/13/2022] Open
Abstract
The RNA polymerase (pol) III transcribes mostly short, house-keeping genes, which produce stable, non-coding RNAs. The tRNAs genes, highly transcribed by pol III in vivo are known replication fork barriers. One of the transcription factors, the PAF1C (RNA polymerase II associated factor 1 complex) is reported to associate with pol I and pol II and influence their transcription. We found low level PAF1C occupancy on the yeast pol III-transcribed genes, which is not correlated with nucleosome positions, pol III occupancy and transcription. PAF1C interacts with the pol III transcription complex and causes pol III loss from the genes under replication stress. Genotoxin exposure causes pol III but not Paf1 loss from the genes. In comparison, Paf1 deletion leads to increased occupancy of pol III, γ-H2A and DNA pol2 in gene-specific manner. Paf1 restricts the accumulation of pol III by influencing the pol III pause on the genes, which reduces the pol III barrier to the replication fork progression.
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40
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Yeganeh M, Praz V, Carmeli C, Villeneuve D, Rib L, Guex N, Herr W, Delorenzi M, Hernandez N. Differential regulation of RNA polymerase III genes during liver regeneration. Nucleic Acids Res 2019; 47:1786-1796. [PMID: 30597109 PMCID: PMC6393285 DOI: 10.1093/nar/gky1282] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/22/2018] [Accepted: 12/14/2018] [Indexed: 12/23/2022] Open
Abstract
Mouse liver regeneration after partial hepatectomy involves cells in the remaining tissue synchronously entering the cell division cycle. We have used this system and H3K4me3, Pol II and Pol III profiling to characterize adaptations in Pol III transcription. Our results broadly define a class of genes close to H3K4me3 and Pol II peaks, whose Pol III occupancy is high and stable, and another class, distant from Pol II peaks, whose Pol III occupancy strongly increases after partial hepatectomy. Pol III regulation in the liver thus entails both highly expressed housekeeping genes and genes whose expression can adapt to increased demand.
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Affiliation(s)
- Meghdad Yeganeh
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Viviane Praz
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland.,SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Cristian Carmeli
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland.,Bioinformatics Core Facility, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Dominic Villeneuve
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Leonor Rib
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Nicolas Guex
- SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Winship Herr
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Mauro Delorenzi
- Bioinformatics Core Facility, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland.,Department of Fundamental Oncology and the Ludwig Center for Cancer research, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Nouria Hernandez
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
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41
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Zhang XO, Gingeras TR, Weng Z. Genome-wide analysis of polymerase III-transcribed Alu elements suggests cell-type-specific enhancer function. Genome Res 2019; 29:1402-1414. [PMID: 31413151 PMCID: PMC6724667 DOI: 10.1101/gr.249789.119] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 07/24/2019] [Indexed: 01/09/2023]
Abstract
Alu elements are one of the most successful families of transposons in the human genome. A portion of Alu elements is transcribed by RNA Pol III, whereas the remaining ones are part of Pol II transcripts. Because Alu elements are highly repetitive, it has been difficult to identify the Pol III–transcribed elements and quantify their expression levels. In this study, we generated high-resolution, long-genomic-span RAMPAGE data in 155 biosamples all with matching RNA-seq data and built an atlas of 17,249 Pol III–transcribed Alu elements. We further performed an integrative analysis on the ChIP-seq data of 10 histone marks and hundreds of transcription factors, whole-genome bisulfite sequencing data, ChIA-PET data, and functional data in several biosamples, and our results revealed that although the human-specific Alu elements are transcriptionally repressed, the older, expressed Alu elements may be exapted by the human host to function as cell-type–specific enhancers for their nearby protein-coding genes.
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Affiliation(s)
- Xiao-Ou Zhang
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Thomas R Gingeras
- Functional Genomics, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.,Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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42
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Cosentino C, Cnop M, Igoillo-Esteve M. The tRNA Epitranscriptome and Diabetes: Emergence of tRNA Hypomodifications as a Cause of Pancreatic β-Cell Failure. Endocrinology 2019; 160:1262-1274. [PMID: 30907926 DOI: 10.1210/en.2019-00098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/15/2019] [Indexed: 01/26/2023]
Abstract
tRNAs are crucial noncoding RNA molecules that serve as amino acid carriers during protein synthesis. The transcription of tRNA genes is a highly regulated process. The tRNA pool is tissue and cell specific, it varies during development, and it is modulated by the environment. tRNAs are highly posttranscriptionally modified by specific tRNA-modifying enzymes. The tRNA modification signature of a cell determines the tRNA epitranscriptome. Perturbations in the tRNA epitranscriptome, as a consequence of mutations in tRNAs and tRNA-modifying enzymes or environmental exposure, have been associated with human disease, including diabetes. tRNA fragmentation induced by impaired tRNA modifications or dietary factors has been linked to pancreatic β-cell demise and paternal inheritance of metabolic traits. Herein, we review recent findings that associate tRNA epitranscriptome perturbations with diabetes.
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Affiliation(s)
- Cristina Cosentino
- ULB Center for Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - Miriam Cnop
- ULB Center for Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
- Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
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43
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de Crécy-Lagard V, Boccaletto P, Mangleburg CG, Sharma P, Lowe TM, Leidel SA, Bujnicki JM. Matching tRNA modifications in humans to their known and predicted enzymes. Nucleic Acids Res 2019; 47:2143-2159. [PMID: 30698754 PMCID: PMC6412123 DOI: 10.1093/nar/gkz011] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/28/2018] [Accepted: 01/10/2019] [Indexed: 12/25/2022] Open
Abstract
tRNA are post-transcriptionally modified by chemical modifications that affect all aspects of tRNA biology. An increasing number of mutations underlying human genetic diseases map to genes encoding for tRNA modification enzymes. However, our knowledge on human tRNA-modification genes remains fragmentary and the most comprehensive RNA modification database currently contains information on approximately 20% of human cytosolic tRNAs, primarily based on biochemical studies. Recent high-throughput methods such as DM-tRNA-seq now allow annotation of a majority of tRNAs for six specific base modifications. Furthermore, we identified large gaps in knowledge when we predicted all cytosolic and mitochondrial human tRNA modification genes. Only 48% of the candidate cytosolic tRNA modification enzymes have been experimentally validated in mammals (either directly or in a heterologous system). Approximately 23% of the modification genes (cytosolic and mitochondrial combined) remain unknown. We discuss these 'unidentified enzymes' cases in detail and propose candidates whenever possible. Finally, tissue-specific expression analysis shows that modification genes are highly expressed in proliferative tissues like testis and transformed cells, but scarcely in differentiated tissues, with the exception of the cerebellum. Our work provides a comprehensive up to date compilation of human tRNA modifications and their enzymes that can be used as a resource for further studies.
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Affiliation(s)
- Valérie de Crécy-Lagard
- Department of Microbiology and Cell Sciences, University of Florida, Gainesville, FL 32611, USA
- Cancer and Genetic Institute, University of Florida, Gainesville, FL 32611, USA
| | - Pietro Boccaletto
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Carl G Mangleburg
- Department of Microbiology and Cell Sciences, University of Florida, Gainesville, FL 32611, USA
| | - Puneet Sharma
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, 48149 Muenster, Germany
- Cells-in-Motion Cluster of Excellence, University of Muenster, 48149 Muenster, Germany
| | - Todd M Lowe
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Sebastian A Leidel
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, 48149 Muenster, Germany
- Cells-in-Motion Cluster of Excellence, University of Muenster, 48149 Muenster, Germany
- Research Group for RNA Biochemistry, Institute of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, ul. Trojdena 4, 02-109 Warsaw, Poland
- Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznań, Poland
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44
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The emerging role of lncRNAs in the regulation of cancer stem cells. Cell Oncol (Dordr) 2018; 41:585-603. [PMID: 30218296 DOI: 10.1007/s13402-018-0406-4] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Tumors contain a functional subpopulation of cells that exhibit stem cell properties. These cells, named cancer stem cells (CSCs), play significant roles in the initiation and progression of cancer. Long non-coding RNAs (lncRNAs) can act at the transcriptional, posttranscriptional and translational level. As such, they may be involved in various biological processes such as DNA damage repair, inflammation, metabolism, cell survival, cell signaling, cell growth and differentiation. Accumulating evidence indicates that lncRNAs are key regulators of the CSC subpopulation, thereby contributing to cancer progression. The aim of this review is to overview current knowledge about the functional role and the mechanisms of action of lncRNAs in the initiation, maintenance and regulation of CSCs derived from different neoplasms. These lncRNAs include CTCF7, ROR, DILC, HOTAIR, H19, HOTTIP, ATB, HIF2PUT, SOX2OT, MALAT-1, CUDR, Lnc34a, Linc00617, DYNC2H1-4, PVT1, SOX4 and ARSR Uc.283-plus. Furthermore, we will illustrate how lncRNAs may regulate asymmetric CSC division and contribute to self-renewal, drug resistance and EMT, thus affecting the metastasis and recurrence of different cancers. In addition, we will highlight the implications of targeting lncRNAs to improve the efficacy of conventional drug therapies and to hamper CSC survival and proliferation. CONCLUSIONS lncRNAs are valuable tools in the search for new targets to selectively eliminate CSCs and improve clinical outcomes. LncRNAs may serve as excellent therapeutic targets because they are stable, easily detectable and expressed in tissue-specific contexts.
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45
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Abstract
The pool of transfer RNA (tRNA) molecules in cells allows the ribosome to decode genetic information. This repertoire of molecular decoders is positioned in the crossroad of the genome, the transcriptome, and the proteome. Omics and systems biology now allow scientists to explore the entire repertoire of tRNAs of many organisms, revealing basic exciting biology. The tRNA gene set of hundreds of species is now characterized, in addition to the tRNA genes of organelles and viruses. Genes encoding tRNAs for certain anticodon types appear in dozens of copies in a genome, while others are universally absent from any genome. Transcriptome measurement of tRNAs is challenging, but in recent years new technologies have allowed researchers to determine the dynamic expression patterns of tRNAs. These advances reveal that availability of ready-to-translate tRNA molecules is highly controlled by several transcriptional and posttranscriptional regulatory processes. This regulation shapes the proteome according to the cellular state. The tRNA pool profoundly impacts many aspects of cellular and organismal life, including protein expression level, translation accuracy, adequacy of folding, and even mRNA stability. As a result, the shape of the tRNA pool affects organismal health and may participate in causing conditions such as cancer and neurological conditions.
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Affiliation(s)
- Roni Rak
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 76100 Israel;
| | - Orna Dahan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 76100 Israel;
| | - Yitzhak Pilpel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 76100 Israel;
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46
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Policarpi C, Crepaldi L, Brookes E, Nitarska J, French SM, Coatti A, Riccio A. Enhancer SINEs Link Pol III to Pol II Transcription in Neurons. Cell Rep 2018; 21:2879-2894. [PMID: 29212033 PMCID: PMC5732322 DOI: 10.1016/j.celrep.2017.11.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 06/30/2017] [Accepted: 11/02/2017] [Indexed: 12/25/2022] Open
Abstract
Spatiotemporal regulation of gene expression depends on the cooperation of multiple mechanisms, including the functional interaction of promoters with distally located enhancers. Here, we show that, in cortical neurons, a subset of short interspersed nuclear elements (SINEs) located in the proximity of activity-regulated genes bears features of enhancers. Enhancer SINEs (eSINEs) recruit the Pol III cofactor complex TFIIIC in a stimulus-dependent manner and are transcribed by Pol III in response to neuronal depolarization. Characterization of an eSINE located in proximity to the Fos gene (FosRSINE1) indicated that the FosRSINE1-encoded transcript interacts with Pol II at the Fos promoter and mediates Fos relocation to Pol II factories, providing an unprecedented molecular link between Pol III and Pol II transcription. Strikingly, knockdown of the FosRSINE1 transcript induces defects of both cortical radial migration in vivo and activity-dependent dendritogenesis in vitro, demonstrating that FosRSINE1 acts as a strong enhancer of Fos expression in diverse physiological contexts.
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Affiliation(s)
- Cristina Policarpi
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Luca Crepaldi
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Emily Brookes
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Justyna Nitarska
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Sarah M French
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Alessandro Coatti
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Antonella Riccio
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK.
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47
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Schorn AJ, Martienssen R. Tie-Break: Host and Retrotransposons Play tRNA. Trends Cell Biol 2018; 28:793-806. [PMID: 29934075 DOI: 10.1016/j.tcb.2018.05.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/08/2018] [Accepted: 05/23/2018] [Indexed: 11/28/2022]
Abstract
tRNA fragments (tRFs) are a class of small, regulatory RNAs with diverse functions. 3'-Derived tRFs perfectly match long terminal repeat (LTR)-retroelements which use the 3'-end of tRNAs to prime reverse transcription. Recent work has shown that tRFs target LTR-retroviruses and -transposons for the RNA interference (RNAi) pathway and also inhibit mobility by blocking reverse transcription. The highly conserved tRNA primer binding site (PBS) in LTR-retroelements is a unique target for 3'-tRFs to recognize and block abundant but diverse LTR-retrotransposons that become transcriptionally active during epigenetic reprogramming in development and disease. 3'-tRFs are processed from full-length tRNAs under so far unknown conditions and potentially protect many cell types. tRFs appear to be an ancient link between RNAi, transposons, and genome stability.
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Affiliation(s)
- Andrea J Schorn
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Rob Martienssen
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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48
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Didychuk AL, Butcher SE, Brow DA. The life of U6 small nuclear RNA, from cradle to grave. RNA (NEW YORK, N.Y.) 2018; 24:437-460. [PMID: 29367453 PMCID: PMC5855946 DOI: 10.1261/rna.065136.117] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Removal of introns from precursor messenger RNA (pre-mRNA) and some noncoding transcripts is an essential step in eukaryotic gene expression. In the nucleus, this process of RNA splicing is carried out by the spliceosome, a multi-megaDalton macromolecular machine whose core components are conserved from yeast to humans. In addition to many proteins, the spliceosome contains five uridine-rich small nuclear RNAs (snRNAs) that undergo an elaborate series of conformational changes to correctly recognize the splice sites and catalyze intron removal. Decades of biochemical and genetic data, along with recent cryo-EM structures, unequivocally demonstrate that U6 snRNA forms much of the catalytic core of the spliceosome and is highly dynamic, interacting with three snRNAs, the pre-mRNA substrate, and >25 protein partners throughout the splicing cycle. This review summarizes the current state of knowledge on how U6 snRNA is synthesized, modified, incorporated into snRNPs and spliceosomes, recycled, and degraded.
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Affiliation(s)
- Allison L Didychuk
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - Samuel E Butcher
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - David A Brow
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53706, USA
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49
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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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Abascal-Palacios G, Ramsay EP, Beuron F, Morris E, Vannini A. Structural basis of RNA polymerase III transcription initiation. Nature 2018; 553:301-306. [PMID: 29345637 DOI: 10.1038/nature25441] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 12/08/2017] [Indexed: 12/14/2022]
Abstract
RNA polymerase (Pol) III transcribes essential non-coding RNAs, including the entire pool of transfer RNAs, the 5S ribosomal RNA and the U6 spliceosomal RNA, and is often deregulated in cancer cells. The initiation of gene transcription by Pol III requires the activity of the transcription factor TFIIIB to form a transcriptionally active Pol III preinitiation complex (PIC). Here we present electron microscopy reconstructions of Pol III PICs at 3.4-4.0 Å and a reconstruction of unbound apo-Pol III at 3.1 Å. TFIIIB fully encircles the DNA and restructures Pol III. In particular, binding of the TFIIIB subunit Bdp1 rearranges the Pol III-specific subunits C37 and C34, thereby promoting DNA opening. The unwound DNA directly contacts both sides of the Pol III cleft. Topologically, the Pol III PIC resembles the Pol II PIC, whereas the Pol I PIC is more divergent. The structures presented unravel the molecular mechanisms underlying the first steps of Pol III transcription and also the general conserved mechanisms of gene transcription initiation.
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Affiliation(s)
| | | | | | - Edward Morris
- The Institute of Cancer Research, London SW7 3RP, UK
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