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Wang X, Wang X, Mu H, Zhao B, Song X, Fan H, Wang B, Yuan F. Global analysis of key post-transcriptional regulation in early leaf development of Limonium bicolor identifies a long non-coding RNA that promotes salt gland development and salt resistance. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:5091-5110. [PMID: 38795330 DOI: 10.1093/jxb/erae241] [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: 07/15/2023] [Accepted: 05/23/2024] [Indexed: 05/27/2024]
Abstract
Limonium bicolor, known horticulturally as sea lavender, is a typical recretohalophyte with salt glands in its leaf epidermis that secrete excess Na+ out of the plant. Although many genes have been proposed to contribute to salt gland initiation and development, a detailed analysis of alternative splicing, alternative polyadenylation patterns, and long non-coding RNAs (lncRNAs) has been lacking. Here, we applied single-molecule long-read mRNA isoform sequencing (Iso-seq) to explore the complexity of the L. bicolor transcriptome in leaves during salt gland initiation (stage A) and salt gland differentiation (stage B) based on the reference genome. We identified alternative splicing events and the use of alternative poly(A) sites unique to stage A or stage B, leading to the hypothesis that they might contribute to the differentiation of salt glands. Based on the Iso-seq data and RNA in situ hybridization of candidate genes, we selected the lncRNA Btranscript_153392 for gene editing and virus-induced gene silencing to dissect its function. In the absence of this transcript, we observed fewer salt glands on the leaf epidermis, leading to diminished salt secretion and salt tolerance. Our data provide transcriptome resources for unraveling the mechanisms behind salt gland development and furthering crop transformation efforts towards enhanced survivability in saline soils.
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Affiliation(s)
- Xi Wang
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
| | - Xiaoyu Wang
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
| | - Huiying Mu
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
| | - Boqing Zhao
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
| | - Xianrui Song
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
| | - Hai Fan
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
| | - Baoshan Wang
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
| | - Fang Yuan
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong, China
- National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying, Shandong, China
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2
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Shayler DW, Stachelek K, Cambier L, Lee S, Bai J, Reid MW, Weisenberger DJ, Bhat B, Aparicio JG, Kim Y, Singh M, Bay M, Thornton ME, Doyle EK, Fouladian Z, Erberich SG, Grubbs BH, Bonaguidi MA, Craft CM, Singh HP, Cobrinik D. Identification and characterization of early human photoreceptor states and cell-state-specific retinoblastoma-related features. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.02.28.530247. [PMID: 38915659 PMCID: PMC11195049 DOI: 10.1101/2023.02.28.530247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Human cone photoreceptors differ from rods and serve as the retinoblastoma cell-of-origin, yet the developmental basis for their distinct behaviors is poorly understood. Here, we used deep full-length single-cell RNA-sequencing to distinguish post-mitotic cone and rod developmental states and identify cone-specific features that contribute to retinoblastomagenesis. The analyses revealed early post-mitotic cone- and rod-directed populations characterized by higher THRB or NRL regulon activities, an immature photoreceptor precursor population with concurrent cone and rod gene and regulon expression, and distinct early and late cone and rod maturation states distinguished by maturation-associated declines in RAX regulon activity. Unexpectedly, both L/M cone and rod precursors co-expressed NRL and THRB RNAs, yet they differentially expressed functionally antagonistic NRL and THRB isoforms and prematurely terminated THRB transcripts. Early L/M cone precursors exhibited successive expression of several lncRNAs along with MYCN, which composed the seventh most L/M-cone-specific regulon, and SYK, which contributed to the early cone precursors' proliferative response to RB1 loss. These findings reveal previously unrecognized photoreceptor precursor states and a role for early cone-precursor-intrinsic SYK expression in retinoblastoma initiation.
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Affiliation(s)
- Dominic W.H. Shayler
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Development, Stem Cell, and Regenerative Medicine Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Kevin Stachelek
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Cancer Biology and Genomics Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Linda Cambier
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Sunhye Lee
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Jinlun Bai
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Development, Stem Cell, and Regenerative Medicine Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Mark W. Reid
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Daniel J. Weisenberger
- Department of Biochemistry & Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Bhavana Bhat
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Jennifer G. Aparicio
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Yeha Kim
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Mitali Singh
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Maxwell Bay
- Development, Stem Cell, and Regenerative Medicine Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Matthew E. Thornton
- Maternal-Fetal Medicine Division of the Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Eamon K. Doyle
- Department of Radiology and The Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Zachary Fouladian
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Development, Stem Cell, and Regenerative Medicine Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Stephan G. Erberich
- Department of Radiology and The Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Brendan H. Grubbs
- Maternal-Fetal Medicine Division of the Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Michael A. Bonaguidi
- Department of Biochemistry & Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Development, Stem Cell, and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Cheryl Mae Craft
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Hardeep P. Singh
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - David Cobrinik
- The Vision Center, Department of Surgery, and Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Department of Biochemistry & Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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3
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Wang Q, Lin J. Homeostasis of mRNA concentrations through coupling transcription, export, and degradation. iScience 2024; 27:110531. [PMID: 39175768 PMCID: PMC11338957 DOI: 10.1016/j.isci.2024.110531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 04/16/2024] [Accepted: 07/15/2024] [Indexed: 08/24/2024] Open
Abstract
Many experiments showed that eukaryotic cells maintain a constant mRNA concentration upon various perturbations by actively regulating mRNA production and degradation rates, known as mRNA buffering. However, the underlying mechanism is still unknown. In this work, we unveil a mechanistic model of mRNA buffering: the releasing-shuttling (RS) model. The model incorporates two crucial proteins, X and Y, which play several roles, including transcription, decay, and export factors, in the different stages of mRNA metabolism. The RS model predicts the constant mRNA concentration under genome-wide genetic perturbations and cell volume changes, the slowed-down mRNA degradation after Pol II depletion, and the temporal transcription dynamics after exonuclease depletion, in agreement with multiple experiments. Finally, we present a list of X and Y candidates and propose an experimental method to identify X. Our work uncovers potentially universal pathways coupling transcription, export, and degradation that help cells maintain mRNA homeostasis.
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Affiliation(s)
- Qirun Wang
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Jie Lin
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
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Sun R, Fisher RP. The CDK9-SPT5 Axis in Control of Transcription Elongation by RNAPII. J Mol Biol 2024:168746. [PMID: 39147127 DOI: 10.1016/j.jmb.2024.168746] [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: 06/21/2024] [Revised: 08/09/2024] [Accepted: 08/09/2024] [Indexed: 08/17/2024]
Abstract
The RNA polymerase II (RNAPII) transcription cycle is regulated at every stage by a network of cyclin-dependent protein kinases (CDKs) and protein phosphatases. Progression of RNAPII from initiation to termination is marked by changing patterns of phosphorylation on the highly repetitive carboxy-terminal domain (CTD) of RPB1, its largest subunit, suggesting the existence of a CTD code. In parallel, the conserved transcription elongation factor SPT5, large subunit of the DRB sensitivity-inducing factor (DSIF), undergoes spatiotemporally regulated changes in phosphorylation state that may be directly linked to the transitions between transcription-cycle phases. Here we review insights gained from recent structural, biochemical, and genetic analyses of human SPT5, which suggest that two of its phosphorylated regions perform distinct functions at different points in transcription. Phosphorylation within a flexible, RNA-binding linker promotes release from the promoter-proximal pause-frequently a rate-limiting step in gene expression-whereas modifications in a repetitive carboxy-terminal region are thought to favor processive elongation, and are removed just prior to termination. Phosphorylations in both motifs depend on CDK9, catalytic subunit of positive transcription elongation factor b (P-TEFb); their different timing of accumulation on chromatin and function during the transcription cycle might reflect their removal by different phosphatases, different kinetics of phosphorylation by CDK9, or both. Perturbations of SPT5 regulation have profound impacts on viability and development in model organisms through largely unknown mechanisms, while enzymes that modify SPT5 have emerged as potential therapeutic targets in cancer; elucidating a putative SPT5 code is therefore a high priority.
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Affiliation(s)
- Rui Sun
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574, USA
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574, USA.
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5
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Lopez Martinez D, Svejstrup JQ. Mechanisms of RNA Polymerase II Termination at the 3'-End of Genes. J Mol Biol 2024:168735. [PMID: 39098594 DOI: 10.1016/j.jmb.2024.168735] [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: 05/17/2024] [Revised: 07/23/2024] [Accepted: 07/30/2024] [Indexed: 08/06/2024]
Abstract
RNA polymerase II (RNAPII) is responsible for the synthesis of a diverse set of RNA molecules, including protein-coding messenger RNAs (mRNAs) and many short non-coding RNAs (ncRNAs). For this purpose, RNAPII relies on a multitude of factors that regulate the transcription cycle, from initiation and promoter-proximal pausing, through elongation and finally termination. RNAPII transcription termination at the end of genes ensures the release of RNAPII from the DNA template and its efficient recycling for further rounds of transcription. Termination of RNAPII is tightly coupled to 3'-end mRNA processing, which constitutes an important trigger for the subsequent transcription termination event. In this review, we discuss the current understanding of RNAPII termination mechanisms, focusing on 'canonical' termination at the 3'-end of genes. We also integrate the allosteric and 'torpedo' models into a unified model of termination, and describe the different termination factors that have been identified to date, paying special attention to the human factors and their mechanism of action at the molecular level. Indeed, in recent years the development of novel approaches in structural biology, biochemistry and cell biology have together led to a more detailed comprehension of the different mechanisms of RNAPII termination, and a better understanding of their importance in regulating gene expression, especially under cellular stress and pathological situations.
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Affiliation(s)
- David Lopez Martinez
- Centre for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Jesper Q Svejstrup
- Centre for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
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Mostafa SM, Wang L, Tian B, Graber J, Moore C. Transcriptomic analysis reveals regulation of adipogenesis via long non-coding RNA, alternative splicing, and alternative polyadenylation. Sci Rep 2024; 14:16964. [PMID: 39043790 PMCID: PMC11266407 DOI: 10.1038/s41598-024-67648-9] [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: 01/28/2024] [Accepted: 07/15/2024] [Indexed: 07/25/2024] Open
Abstract
Obesity is characterized by dysregulated adipogenesis that leads to increased number and/or size of adipocytes. Understanding the molecular mechanisms governing adipogenesis is therefore key to designing therapeutic interventions against obesity. In our study, we analyzed 3'-end sequencing data that we generated from human preadipocytes and adipocytes, as well as previously published RNA-seq datasets, to elucidate mechanisms of regulation via long non-coding RNA (lncRNA), alternative splicing (AS) and alternative polyadenylation (APA). We discovered lncRNAs that have not been previously characterized but may be key regulators of white adipogenesis. We also detected 100 AS events and, using motif enrichment analysis, identified RNA binding proteins (RBPs) that could mediate exon skipping-the most prevalent AS event. In addition, we show that usage of alternative poly(A) sites in introns or 3'-UTRs of key adipogenesis genes leads to isoform diversity, which can have significant biological consequences on differentiation efficiency. We also identified RBPs that may modulate APA and defined how 3'-UTR APA can regulate gene expression through gain or loss of specific microRNA binding sites. Taken together, our bioinformatics-based analysis reveals potential therapeutic avenues for obesity through manipulation of lncRNA levels and the profile of mRNA isoforms via alternative splicing and polyadenylation.
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Affiliation(s)
- Salwa Mohd Mostafa
- Graduate School of Biomedical Sciences and Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Luyang Wang
- Gene Expression and Regulation Program, and Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA, 19104, USA
| | - Bin Tian
- Gene Expression and Regulation Program, and Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA, 19104, USA
| | - Joel Graber
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME, 04609, USA
| | - Claire Moore
- Graduate School of Biomedical Sciences and Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA, 02111, USA.
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Ottesen EW, Singh NN, Seo J, Singh RN. U1 snRNA interactions with deep intronic sequences regulate splicing of multiple exons of spinal muscular atrophy genes. Front Neurosci 2024; 18:1412893. [PMID: 39086841 PMCID: PMC11289892 DOI: 10.3389/fnins.2024.1412893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 07/02/2024] [Indexed: 08/02/2024] Open
Abstract
Introduction The U1 small nuclear RNA (snRNA) forms ribonucleoprotein particles (RNPs) such as U1 snRNP and U1-TAF15 snRNP. U1 snRNP is one of the most studied RNPs due to its critical role in pre-mRNA splicing in defining the 5' splice site (5'ss) of every exon through direct interactions with sequences at exon/intron junctions. Recent reports support the role of U1 snRNP in all steps of transcription, namely initiation, elongation, and termination. Functions of U1-TAF15 snRNP are less understood, though it associates with the transcription machinery and may modulate pre-mRNA splicing by interacting with the 5'ss and/or 5'ss-like sequences within the pre-mRNA. An anti-U1 antisense oligonucleotide (ASO) that sequesters the 5' end of U1 snRNA inhibits the functions of U1 snRNP, including transcription and splicing. However, it is not known if the inhibition of U1 snRNP influences post-transcriptional regulation of pre-mRNA splicing through deep intronic sequences. Methods We examined the effect of an anti-U1 ASO that sequesters the 5' end of U1 snRNA on transcription and splicing of all internal exons of the spinal muscular atrophy (SMA) genes, SMN1 and SMN2. Our study was enabled by the employment of a multi-exon-skipping detection assay (MESDA) that discriminates against prematurely terminated transcripts. We employed an SMN2 super minigene to determine if anti-U1 ASO differently affects splicing in the context of truncated introns. Results We observed substantial skipping of multiple internal exons of SMN1 and SMN2 triggered by anti-U1 treatment. Suggesting a role for U1 snRNP in interacting with deep intronic sequences, early exons of the SMN2 super minigene with truncated introns were resistant to anti-U1 induced skipping. Consistently, overexpression of engineered U1 snRNAs targeting the 5'ss of early SMN1 and SMN2 exons did not prevent exon skipping caused by anti-U1 treatment. Discussion Our results uncover a unique role of the U1 snRNA-associated RNPs in splicing regulation executed through deep intronic sequences. Findings are significant for developing novel therapies for SMA based on deep intronic targets.
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Affiliation(s)
| | | | | | - Ravindra N. Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
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Wang X, Carvajal-Moreno J, Zhao X, Li J, Hernandez VA, Yalowich JC, Elton TS. Circumvention of Topoisomerase II α Intron 19 Intronic Polyadenylation in Acquired Etoposide-Resistant Human Leukemia K562 Cells. Mol Pharmacol 2024; 106:33-46. [PMID: 38719474 PMCID: PMC11187689 DOI: 10.1124/molpharm.124.000868] [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: 01/03/2024] [Accepted: 04/12/2024] [Indexed: 06/20/2024] Open
Abstract
DNA topoisomerase IIα (TOP2α; 170 kDa, TOP2α/170) is an essential enzyme for proper chromosome dysjunction by producing transient DNA double-stranded breaks and is an important target for DNA damage-stabilizing anticancer agents, such as etoposide. Therapeutic effects of TOP2α poisons can be limited due to acquired drug resistance. We previously demonstrated decreased TOP2α/170 levels in an etoposide-resistant human leukemia K562 subline, designated K/VP.5, accompanied by increased expression of a C-terminal truncated TOP2α isoform (90 kDa; TOP2α/90), which heterodimerized with TOP2α/170 and was a determinant of resistance by exhibiting dominant-negative effects against etoposide activity. Based on 3'-rapid amplification of cDNA ends, we confirmed TOP2α/90 as the translation product of a TOP2α mRNA in which a cryptic polyadenylation site (PAS) harbored in intron 19 (I19) was used. In this report, we investigated whether the resultant intronic polyadenylation (IPA) would be attenuated by blocking or mutating the I19 PAS, thereby circumventing acquired drug resistance. An antisense morpholino oligonucleotide was used to hybridize/block the PAS in TOP2α pre-mRNA in K/VP.5 cells, resulting in decreased TOP2α/90 mRNA/protein levels in K/VP.5 cells and partially circumventing drug resistance. Subsequently, CRISPR/CRISPR-associated protein 9 with homology-directed repair was used to mutate the cryptic I19 PAS (AATAAA→ACCCAA) to prevent IPA. Gene-edited clones exhibited increased TOP2α/170 and decreased TOP2α/90 mRNA/protein and demonstrated restored sensitivity to etoposide and other TOP2α-targeted drugs. Together, results indicated that blocking/mutating a cryptic I19 PAS in K/VP.5 cells reduced IPA and restored sensitivity to TOP2α-targeting drugs. SIGNIFICANCE STATEMENT: The results presented in this study indicate that CRISPR/CRISPR-associated protein 9 gene editing of a cryptic polyadenylation site (PAS) within I19 of the TOP2α gene results in the reversal of acquired resistance to etoposide and other TOP2-targeted drugs. An antisense morpholino oligonucleotide targeting the PAS also partially circumvented resistance.
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Affiliation(s)
- Xinyi Wang
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Jessika Carvajal-Moreno
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Xinyu Zhao
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Junan Li
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Victor A Hernandez
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Jack C Yalowich
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Terry S Elton
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
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Fombellida-Lopez C, Berkhout B, Darcis G, Pasternak AO. Persistent HIV-1 transcription during ART: time to reassess its significance? Curr Opin HIV AIDS 2024; 19:124-132. [PMID: 38502547 PMCID: PMC10990031 DOI: 10.1097/coh.0000000000000849] [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] [Indexed: 03/21/2024]
Abstract
PURPOSE OF REVIEW Despite suppressive antiretroviral therapy (ART), HIV-1 reservoirs persist and reignite viral replication if therapy is interrupted. Persistence of the viral reservoir in people with HIV-1 (PWH) is the main obstacle to an HIV-1 cure. The reservoirs are not transcriptionally silent, and viral transcripts can be detected in most ART-treated individuals. Here, we review the recent progress in the characterization of persistent HIV-1 transcription during ART. RECENT FINDINGS Evidence from several studies indicates that, although cell-associated unspliced (US) HIV-1 RNA is abundantly expressed in ART-treated PWH, intact full-length US transcripts are rare and most US RNA is derived from defective proviruses. The transcription- and translation-competent defective proviruses, previously considered irrelevant, are increasingly being linked to residual HIV-1 pathogenesis under suppressive ART. Recent data suggest a continuous crosstalk between the residual HIV-1 activity under ART and the immune system. Persistent HIV-1 transcription on ART, despite being mostly derived from defective proviruses, predicts viral rebound upon therapy interruption, suggesting its role as an indicator of the strength of the host antiviral immune response that is shaping the viral rebound. SUMMARY In light of the recent findings, the significance of persistent HIV-1 transcription during ART for the long-term health of PWH and the cure research should be reassessed.
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Affiliation(s)
- Céline Fombellida-Lopez
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory of Immunology and Infectious Diseases, GIGA-Institute, University of Liège
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Gilles Darcis
- Laboratory of Immunology and Infectious Diseases, GIGA-Institute, University of Liège
- Department of General Internal Medicine and Infectious Diseases, University Hospital of Liège, Liège, Belgium
| | - Alexander O. Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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10
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Rambout X, Maquat LE. Nuclear mRNA decay: regulatory networks that control gene expression. Nat Rev Genet 2024:10.1038/s41576-024-00712-2. [PMID: 38637632 DOI: 10.1038/s41576-024-00712-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2024] [Indexed: 04/20/2024]
Abstract
Proper regulation of mRNA production in the nucleus is critical for the maintenance of cellular homoeostasis during adaptation to internal and environmental cues. Over the past 25 years, it has become clear that the nuclear machineries governing gene transcription, pre-mRNA processing, pre-mRNA and mRNA decay, and mRNA export to the cytoplasm are inextricably linked to control the quality and quantity of mRNAs available for translation. More recently, an ever-expanding diversity of new mechanisms by which nuclear RNA decay factors finely tune the expression of protein-encoding genes have been uncovered. Here, we review the current understanding of how mammalian cells shape their protein-encoding potential by regulating the decay of pre-mRNAs and mRNAs in the nucleus.
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Affiliation(s)
- Xavier Rambout
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA.
- Center for RNA Biology, University of Rochester, Rochester, NY, USA.
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA.
- Center for RNA Biology, University of Rochester, Rochester, NY, USA.
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11
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Boddu PC, Gupta AK, Roy R, De La Peña Avalos B, Olazabal-Herrero A, Neuenkirchen N, Zimmer JT, Chandhok NS, King D, Nannya Y, Ogawa S, Lin H, Simon MD, Dray E, Kupfer GM, Verma A, Neugebauer KM, Pillai MM. Transcription elongation defects link oncogenic SF3B1 mutations to targetable alterations in chromatin landscape. Mol Cell 2024; 84:1475-1495.e18. [PMID: 38521065 PMCID: PMC11061666 DOI: 10.1016/j.molcel.2024.02.032] [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: 03/28/2023] [Revised: 11/26/2023] [Accepted: 02/27/2024] [Indexed: 03/25/2024]
Abstract
Transcription and splicing of pre-messenger RNA are closely coordinated, but how this functional coupling is disrupted in human diseases remains unexplored. Using isogenic cell lines, patient samples, and a mutant mouse model, we investigated how cancer-associated mutations in SF3B1 alter transcription. We found that these mutations reduce the elongation rate of RNA polymerase II (RNAPII) along gene bodies and its density at promoters. The elongation defect results from disrupted pre-spliceosome assembly due to impaired protein-protein interactions of mutant SF3B1. The decreased promoter-proximal RNAPII density reduces both chromatin accessibility and H3K4me3 marks at promoters. Through an unbiased screen, we identified epigenetic factors in the Sin3/HDAC/H3K4me pathway, which, when modulated, reverse both transcription and chromatin changes. Our findings reveal how splicing factor mutant states behave functionally as epigenetic disorders through impaired transcription-related changes to the chromatin landscape. We also present a rationale for targeting the Sin3/HDAC complex as a therapeutic strategy.
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Affiliation(s)
- Prajwal C Boddu
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Abhishek K Gupta
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Rahul Roy
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Bárbara De La Peña Avalos
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center (UTHSC) at San Antonio, San Antonio, TX, USA
| | - Anne Olazabal-Herrero
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Nils Neuenkirchen
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA; Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT, USA
| | - Joshua T Zimmer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Namrata S Chandhok
- Division of Hematology, Department of Medicine, Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL, USA
| | - Darren King
- Section of Hematology and Medical Oncology, Department of Internal Medicine and Rogel Cancer Center, University of Michigan Health, Ann Arbor, MI, USA
| | - Yasuhito Nannya
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Haifan Lin
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA; Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT, USA
| | - Matthew D Simon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Eloise Dray
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center (UTHSC) at San Antonio, San Antonio, TX, USA
| | - Gary M Kupfer
- Department of Oncology and Pediatrics, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
| | - Amit Verma
- Division of Hemato-Oncology, Department of Medicine and Department of Developmental and Molecular Biology, Albert Einstein-Montefiore Cancer Center, New York, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Yale Center for RNA Science and Medicine, Yale University, New Haven, CT, USA
| | - Manoj M Pillai
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA; Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT, USA; Yale Center for RNA Science and Medicine, Yale University, New Haven, CT, USA; Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.
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12
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Ait Said M, Bejjani F, Abdouni A, Ségéral E, Emiliani S. Premature transcription termination complex proteins PCF11 and WDR82 silence HIV-1 expression in latently infected cells. Proc Natl Acad Sci U S A 2023; 120:e2313356120. [PMID: 38015843 PMCID: PMC10710072 DOI: 10.1073/pnas.2313356120] [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: 08/03/2023] [Accepted: 10/30/2023] [Indexed: 11/30/2023] Open
Abstract
Postintegration transcriptional silencing of HIV-1 leads to the establishment of a pool of latently infected cells. In these cells, mechanisms controlling RNA Polymerase II (RNAPII) pausing and premature transcription termination (PTT) remain to be explored. Here, we found that the cleavage and polyadenylation (CPA) factor PCF11 represses HIV-1 expression independently of the other subunits of the CPA complex or the polyadenylation signal located at the 5' LTR. We show that PCF11 interacts with the RNAPII-binding protein WDR82. Knock-down of PCF11 or WDR82 reactivated HIV-1 expression in latently infected cells. To silence HIV-1 transcription, PCF11 and WDR82 are specifically recruited at the promoter-proximal region of the provirus in an interdependent manner. Codepletion of PCF11 and WDR82 indicated that they act on the same pathway to repress HIV expression. These findings reveal PCF11/WDR82 as a PTT complex silencing HIV-1 expression in latently infected cells.
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Affiliation(s)
- Melissa Ait Said
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Fabienne Bejjani
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Ahmed Abdouni
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Emmanuel Ségéral
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Stéphane Emiliani
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
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13
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Abstract
Transcription and replication both require large macromolecular complexes to act on a DNA template, yet these machineries cannot simultaneously act on the same DNA sequence. Conflicts between the replication and transcription machineries (transcription-replication conflicts, or TRCs) are widespread in both prokaryotes and eukaryotes and have the capacity to both cause DNA damage and compromise complete, faithful replication of the genome. This review will highlight recent studies investigating the genomic locations of TRCs and the mechanisms by which they may be prevented, mitigated, or resolved. We address work from both model organisms and mammalian systems but predominantly focus on multicellular eukaryotes owing to the additional complexities inherent in the coordination of replication and transcription in the context of cell type-specific gene expression and higher-order chromatin organization.
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Affiliation(s)
- Liana Goehring
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA;
| | - Tony T Huang
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA;
| | - Duncan J Smith
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, USA;
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14
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Aoi Y, Shilatifard A. Transcriptional elongation control in developmental gene expression, aging, and disease. Mol Cell 2023; 83:3972-3999. [PMID: 37922911 DOI: 10.1016/j.molcel.2023.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/23/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
The elongation stage of transcription by RNA polymerase II (RNA Pol II) is central to the regulation of gene expression in response to developmental and environmental cues in metazoan. Dysregulated transcriptional elongation has been associated with developmental defects as well as disease and aging processes. Decades of genetic and biochemical studies have painstakingly identified and characterized an ensemble of factors that regulate RNA Pol II elongation. This review summarizes recent findings taking advantage of genetic engineering techniques that probe functions of elongation factors in vivo. We propose a revised model of elongation control in this accelerating field by reconciling contradictory results from the earlier biochemical evidence and the recent in vivo studies. We discuss how elongation factors regulate promoter-proximal RNA Pol II pause release, transcriptional elongation rate and processivity, RNA Pol II stability and RNA processing, and how perturbation of these processes is associated with developmental disorders, neurodegenerative disease, cancer, and aging.
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Affiliation(s)
- Yuki Aoi
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ali Shilatifard
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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15
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Stroup EK, Ji Z. Deep learning of human polyadenylation sites at nucleotide resolution reveals molecular determinants of site usage and relevance in disease. Nat Commun 2023; 14:7378. [PMID: 37968271 PMCID: PMC10651852 DOI: 10.1038/s41467-023-43266-3] [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: 01/28/2023] [Accepted: 11/05/2023] [Indexed: 11/17/2023] Open
Abstract
The genomic distribution of cleavage and polyadenylation (polyA) sites should be co-evolutionally optimized with the local gene structure. Otherwise, spurious polyadenylation can cause premature transcription termination and generate aberrant proteins. To obtain mechanistic insights into polyA site optimization across the human genome, we develop deep/machine learning models to identify genome-wide putative polyA sites at unprecedented nucleotide-level resolution and calculate their strength and usage in the genomic context. Our models quantitatively measure position-specific motif importance and their crosstalk in polyA site formation and cleavage heterogeneity. The intronic site expression is governed by the surrounding splicing landscape. The usage of alternative polyA sites in terminal exons is modulated by their relative locations and distance to downstream genes. Finally, we apply our models to reveal thousands of disease- and trait-associated genetic variants altering polyadenylation activity. Altogether, our models represent a valuable resource to dissect molecular mechanisms mediating genome-wide polyA site expression and characterize their functional roles in human diseases.
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Affiliation(s)
- Emily Kunce Stroup
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Zhe Ji
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60628, USA.
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16
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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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17
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Zhu P, Schon M, Questa J, Nodine M, Dean C. Causal role of a promoter polymorphism in natural variation of the Arabidopsis floral repressor gene FLC. Curr Biol 2023; 33:4381-4391.e3. [PMID: 37729909 DOI: 10.1016/j.cub.2023.08.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 07/06/2023] [Accepted: 08/25/2023] [Indexed: 09/22/2023]
Abstract
Noncoding polymorphism frequently associates with phenotypic variation, but causation and mechanism are rarely established. Noncoding single-nucleotide polymorphisms (SNPs) characterize the major haplotypes of the Arabidopsis thaliana floral repressor gene FLOWERING LOCUS C (FLC). This noncoding polymorphism generates a range of FLC expression levels, determining the requirement for and the response to winter cold. The major adaptive determinant of these FLC haplotypes was shown to be the autumnal levels of FLC expression. Here, we investigate how noncoding SNPs influence FLC transcriptional output. We identify an upstream transcription start site (uTSS) cluster at FLC, whose usage is increased by an A variant at the promoter SNP-230. This variant is present in relatively few Arabidopsis accessions, with the majority containing G at this site. We demonstrate a causal role for the A variant at -230 in reduced FLC transcriptional output. The G variant upregulates FLC expression redundantly with the major transcriptional activator FRIGIDA (FRI). We demonstrate an additive interaction of SNP-230 with an intronic SNP+259, which also differentially influences uTSS usage. Combinatorial interactions between noncoding SNPs and transcriptional activators thus generate quantitative variation in FLC transcription that has facilitated the adaptation of Arabidopsis accessions to distinct climates.
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Affiliation(s)
- Pan Zhu
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Schon
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Julia Questa
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Nodine
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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18
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Cao Y, Qin Y, Zhang W, Tian W, Ren Y, Ren J, Wang J, Wang M, Jiang J, Wang Z. Structural basis of the human negative elongation factor NELF-B/C/E ternary complex. Biochem Biophys Res Commun 2023; 677:155-161. [PMID: 37591184 DOI: 10.1016/j.bbrc.2023.08.019] [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: 08/03/2023] [Accepted: 08/09/2023] [Indexed: 08/19/2023]
Abstract
Negative elongation factor (NELF) is a four-subunit transcription elongation factor that mainly functions in maintaining the paused state of RNA polymerase II in eukaryotes. Upon binding to Pol II, NELF works synergistically with DRB sensitivity-inducing factor (DSIF) and inhibits transcription elongation of Pol II, which subsequently retains a stably paused state 20-60 base pairs downstream of the promoter. The promoter-proximal pausing of Pol II caused by NELF is a general mechanism of transcriptional regulation for most signal-responsive genes. To date, structural studies have significantly advanced our understanding of the molecular mechanisms of NELF. However, a high quality structural model clarifying the interaction details of this complex is still lacking. In this study, we solved the high resolution crystal structure of the NELF-B/C/E ternary complex. We observed detailed interactions between subunits and identified residues important for the association between NELF-B and NELF-E. Our work presents a precise model of the NELF complex, which will facilitate our understanding of its in vivo function.
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Affiliation(s)
- Yinghua Cao
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Yan Qin
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Weidi Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Wei Tian
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Yanpeng Ren
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Jiahao Ren
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Junmeng Wang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Meng Wang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Junyi Jiang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China.
| | - Zhanxin Wang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China.
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19
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Zheng H, Jin Q, Wang X, Qi Y, Liu W, Ren Y, Zhao D, Xavier Chen F, Cheng J, Chen X, Xu Y. Structural basis of INTAC-regulated transcription. Protein Cell 2023; 14:698-702. [PMID: 36869814 PMCID: PMC10501182 DOI: 10.1093/procel/pwad010] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/05/2023] Open
Affiliation(s)
- Hai Zheng
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Qianwei Jin
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xinxin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yilun Qi
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Weida Liu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yulei Ren
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Dan Zhao
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Fei Xavier Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jingdong Cheng
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xizi Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
- The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
- Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China
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20
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Kaur P, Nagar S, Mehta R, Sahadeo K, Vancura A. Hydroxyurea and inactivation of checkpoint kinase MEC1 inhibit transcription termination and pre-mRNA cleavage at polyadenylation sites in budding yeast. Sci Rep 2023; 13:13106. [PMID: 37567961 PMCID: PMC10421882 DOI: 10.1038/s41598-023-40294-3] [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: 02/16/2023] [Accepted: 08/08/2023] [Indexed: 08/13/2023] Open
Abstract
The DNA damage response (DDR) is an evolutionarily conserved process essential for cell survival. The transcription changes triggered by DDR depend on the nature of DNA damage, activation of checkpoint kinases, and the stage of cell cycle. The transcription changes can be localized and affect only damaged DNA, but they can be also global and affect genes that are not damaged. While the purpose of localized transcription inhibition is to avoid transcription of damaged genes and make DNA accessible for repair, the purpose and mechanisms of global transcription inhibition of undamaged genes are less well understood. We show here that a brief cell treatment with hydroxyurea (HU) globally inhibits RNA synthesis and transcription by RNA polymerase I, II, and III (RNAPI, RNAPII, and RNAPIII). HU reduces efficiency of transcription termination and inhibits pre-mRNA cleavage at the polyadenylation (pA) sites, destabilizes mRNAs, and shortens poly(A) tails of mRNAs, indicating defects in pre-mRNA 3' end processing. Inactivation of the checkpoint kinase Mec1p downregulates the efficiency of transcription termination and reduces the efficiency of pre-mRNAs clevage at the pA sites, suggesting the involvement of DNA damage checkpoint in transcription termination and pre-mRNA 3' end processing.
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Affiliation(s)
- Pritpal Kaur
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439, USA
| | - Shreya Nagar
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439, USA
| | - Riddhi Mehta
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439, USA
| | - Kyle Sahadeo
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439, USA
| | - Ales Vancura
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439, USA.
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21
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Xu W, Li X. Regulation of Pol II Pausing during Daily Gene Transcription in Mouse Liver. BIOLOGY 2023; 12:1107. [PMID: 37626993 PMCID: PMC10452108 DOI: 10.3390/biology12081107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/20/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023]
Abstract
Cell autonomous circadian oscillation is present in central and various peripheral tissues. The intrinsic tissue clock and various extrinsic cues drive gene expression rhythms. Transcription regulation is thought to be the main driving force for gene rhythms. However, how transcription rhythms arise remains to be fully characterized due to the fact that transcription is regulated at multiple steps. In particular, Pol II recruitment, pause release, and premature transcription termination are critical regulatory steps that determine the status of Pol II pausing and transcription output near the transcription start site (TSS) of the promoter. Recently, we showed that Pol II pausing exhibits genome-wide changes during daily transcription in mouse liver. In this article, we review historical as well as recent findings on the regulation of transcription rhythms by the circadian clock and other transcription factors, and the potential limitations of those results in explaining rhythmic transcription at the TSS. We then discuss our results on the genome-wide characteristics of daily changes in Pol II pausing, the possible regulatory mechanisms involved, and their relevance to future research on circadian transcription regulation.
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Affiliation(s)
| | - Xiaodong Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China;
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22
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Rodríguez‐Molina JB, Turtola M. Birth of a poly(A) tail: mechanisms and control of mRNA polyadenylation. FEBS Open Bio 2023; 13:1140-1153. [PMID: 36416579 PMCID: PMC10315857 DOI: 10.1002/2211-5463.13528] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022] Open
Abstract
During their synthesis in the cell nucleus, most eukaryotic mRNAs undergo a two-step 3'-end processing reaction in which the pre-mRNA is cleaved and released from the transcribing RNA polymerase II and a polyadenosine (poly(A)) tail is added to the newly formed 3'-end. These biochemical reactions might appear simple at first sight (endonucleolytic RNA cleavage and synthesis of a homopolymeric tail), but their catalysis requires a multi-faceted enzymatic machinery, the cleavage and polyadenylation complex (CPAC), which is composed of more than 20 individual protein subunits. The activity of CPAC is further orchestrated by Poly(A) Binding Proteins (PABPs), which decorate the poly(A) tail during its synthesis and guide the mRNA through subsequent gene expression steps. Here, we review the structure, molecular mechanism, and regulation of eukaryotic mRNA 3'-end processing machineries with a focus on the polyadenylation step. We concentrate on the CPAC and PABPs from mammals and the budding yeast, Saccharomyces cerevisiae, because these systems are the best-characterized at present. Comparison of their functions provides valuable insights into the principles of mRNA 3'-end processing.
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Affiliation(s)
| | - Matti Turtola
- Department of Life TechnologiesUniversity of TurkuFinland
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23
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Streb P, Kowarz E, Benz T, Reis J, Marschalek R. How chromosomal translocations arise to cause cancer: Gene proximity, trans-splicing, and DNA end joining. iScience 2023; 26:106900. [PMID: 37378346 PMCID: PMC10291325 DOI: 10.1016/j.isci.2023.106900] [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: 11/28/2022] [Revised: 04/01/2023] [Accepted: 05/12/2023] [Indexed: 06/29/2023] Open
Abstract
Chromosomal translocations (CTs) are a genetic hallmark of cancer. They could be identified as recurrent genetic aberrations in hemato-malignancies and solid tumors. More than 40% of all "cancer genes" were identified in recurrent CTs. Most of these CTs result in the production of oncofusion proteins of which many have been studied over the past decades. They influence signaling pathways and/or alter gene expression. However, a precise mechanism for how these CTs arise and occur in a nearly identical fashion in individuals remains to be elucidated. Here, we performed experiments that explain the onset of CTs: (1) proximity of genes able to produce prematurely terminated transcripts, which lead to the production of (2) trans-spliced fusion RNAs, and finally, the induction of (3) DNA double-strand breaks which are subsequently repaired via EJ repair pathways. Under these conditions, balanced chromosomal translocations could be specifically induced. The implications of these findings will be discussed.
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Affiliation(s)
- Patrick Streb
- Goethe-University, Department Biochemistry, Chemistry & Pharmacy, Institute of Pharmaceutical Biology, Max-von-Laue-Street 9, 60438 Frankfurt am Main, Germany
| | - Eric Kowarz
- Goethe-University, Department Biochemistry, Chemistry & Pharmacy, Institute of Pharmaceutical Biology, Max-von-Laue-Street 9, 60438 Frankfurt am Main, Germany
| | - Tamara Benz
- Goethe-University, Department Biochemistry, Chemistry & Pharmacy, Institute of Pharmaceutical Biology, Max-von-Laue-Street 9, 60438 Frankfurt am Main, Germany
| | - Jennifer Reis
- Goethe-University, Department Biochemistry, Chemistry & Pharmacy, Institute of Pharmaceutical Biology, Max-von-Laue-Street 9, 60438 Frankfurt am Main, Germany
| | - Rolf Marschalek
- Goethe-University, Department Biochemistry, Chemistry & Pharmacy, Institute of Pharmaceutical Biology, Max-von-Laue-Street 9, 60438 Frankfurt am Main, Germany
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24
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Vlasenok M, Margasyuk S, Pervouchine DD. Transcriptome sequencing suggests that pre-mRNA splicing counteracts widespread intronic cleavage and polyadenylation. NAR Genom Bioinform 2023; 5:lqad051. [PMID: 37260513 PMCID: PMC10227441 DOI: 10.1093/nargab/lqad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/09/2023] [Accepted: 05/17/2023] [Indexed: 06/02/2023] Open
Abstract
Alternative splicing (AS) and alternative polyadenylation (APA) are two crucial steps in the post-transcriptional regulation of eukaryotic gene expression. Protocols capturing and sequencing RNA 3'-ends have uncovered widespread intronic polyadenylation (IPA) in normal and disease conditions, where it is currently attributed to stochastic variations in the pre-mRNA processing. Here, we took advantage of the massive amount of RNA-seq data generated by the Genotype Tissue Expression project (GTEx) to simultaneously identify and match tissue-specific expression of intronic polyadenylation sites with tissue-specific splicing. A combination of computational methods including the analysis of short reads with non-templated adenines revealed that APA events are more abundant in introns than in exons. While the rate of IPA in composite terminal exons and skipped terminal exons expectedly correlates with splicing, we observed a considerable fraction of IPA events that lack AS support and attributed them to spliced polyadenylated introns (SPI). We hypothesize that SPIs represent transient byproducts of a dynamic coupling between APA and AS, in which the spliceosome removes the intron while it is being cleaved and polyadenylated. These findings indicate that cotranscriptional pre-mRNA splicing could serve as a rescue mechanism to suppress premature transcription termination at intronic polyadenylation sites.
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Affiliation(s)
- Maria Vlasenok
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Bolshoy Bulvar 30, Moscow 121205, Russia
| | - Sergey Margasyuk
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Bolshoy Bulvar 30, Moscow 121205, Russia
| | - Dmitri D Pervouchine
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Bolshoy Bulvar 30, Moscow 121205, Russia
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25
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Weiß E, Hennig T, Graßl P, Djakovic L, Whisnant AW, Jürges CS, Koller F, Kluge M, Erhard F, Dölken L, Friedel CC. HSV-1 Infection Induces a Downstream Shift of Promoter-Proximal Pausing for Host Genes. J Virol 2023; 97:e0038123. [PMID: 37093003 PMCID: PMC10231138 DOI: 10.1128/jvi.00381-23] [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: 03/10/2023] [Accepted: 04/03/2023] [Indexed: 04/25/2023] Open
Abstract
Herpes simplex virus 1 (HSV-1) infection exerts a profound shutoff of host gene expression at multiple levels. Recently, HSV-1 infection was reported to also impact promoter-proximal RNA polymerase II (Pol II) pausing, a key step in the eukaryotic transcription cycle, with decreased and increased Pol II pausing observed for activated and repressed genes, respectively. Here, we demonstrate that HSV-1 infection induces more complex alterations in promoter-proximal pausing than previously suspected for the vast majority of cellular genes. While pausing is generally retained, it is shifted to more downstream and less well-positioned sites for most host genes. The downstream shift of Pol II pausing was established between 1.5 and 3 h of infection, remained stable until at least 6 hours postinfection, and was observed in the absence of ICP22. The shift in Pol II pausing does not result from alternative de novo transcription initiation at downstream sites or read-in transcription originating from disruption of transcription termination of upstream genes. The use of downstream secondary pause sites associated with +1 nucleosomes was previously observed upon negative elongation factor (NELF) depletion. However, downstream shifts of Pol II pausing in HSV-1 infection were much more pronounced than observed upon NELF depletion. Thus, our study reveals a novel aspect in which HSV-1 infection fundamentally reshapes host transcriptional processes, providing new insights into the regulation of promoter-proximal Pol II pausing in eukaryotic cells. IMPORTANCE This study provides a genome-wide analysis of changes in promoter-proximal polymerase II (Pol II) pausing on host genes induced by HSV-1 infection. It shows that standard measures of pausing, i.e., pausing indices, do not properly capture the complex and unsuspected alterations in Pol II pausing occurring in HSV-1 infection. Instead of a reduction of pausing with increased elongation, as suggested by pausing index analysis, HSV-1 infection leads to a shift of pausing to downstream and less well-positioned sites than in uninfected cells for the majority of host genes. Thus, HSV-1 infection fundamentally reshapes a key regulatory step at the beginning of the host transcriptional cycle on a genome-wide scale.
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Affiliation(s)
- Elena Weiß
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Hennig
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Pilar Graßl
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lara Djakovic
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Adam W. Whisnant
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Christopher S. Jürges
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Franziska Koller
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Kluge
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Florian Erhard
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Lars Dölken
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Center for Infection Research (HZI), Würzburg, Germany
| | - Caroline C. Friedel
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
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26
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Marquardt S, Petrillo E, Manavella PA. Cotranscriptional RNA processing and modification in plants. THE PLANT CELL 2023; 35:1654-1670. [PMID: 36259932 PMCID: PMC10226594 DOI: 10.1093/plcell/koac309] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/14/2022] [Indexed: 05/30/2023]
Abstract
The activities of RNA polymerases shape the epigenetic landscape of genomes with profound consequences for genome integrity and gene expression. A fundamental event during the regulation of eukaryotic gene expression is the coordination between transcription and RNA processing. Most primary RNAs mature through various RNA processing and modification events to become fully functional. While pioneering results positioned RNA maturation steps after transcription ends, the coupling between the maturation of diverse RNA species and their transcription is becoming increasingly evident in plants. In this review, we discuss recent advances in our understanding of the crosstalk between RNA Polymerase II, IV, and V transcription and nascent RNA processing of both coding and noncoding RNAs.
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Affiliation(s)
- Sebastian Marquardt
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Frederiksberg, Denmark
| | - Ezequiel Petrillo
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-CONICET-UBA), Buenos Aires, C1428EHA, Argentina
| | - Pablo A Manavella
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
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27
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Tschage L, Kowarz E, Marschalek R. Model System to Analyze RNA-Mediated DNA Repair in Mammalian Cells. CRISPR J 2023. [PMID: 37200486 DOI: 10.1089/crispr.2022.0105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
"RNA-templated/directed DNA repair" is a biological mechanism that has been experimentally demonstrated in bacteria, yeast, and mammalian cells. Recent study has shown that small noncoding RNAs (DDRNAs) and/or newly RNAPII transcribed RNAs (dilncRNAs) are orchestrating the initial steps of double-strand break (DSB) repair. In this study, we demonstrate that also pre-mRNA could be used as direct or indirect substrate for DSB repair. Our test system is based on (1) a stably integrated mutant reporter gene that produces constitutively a nonspliceable pre-mRNA, (2) a transiently expressed sgRNA-guided dCas13b::ADAR fusion protein to specifically RNA edit the nonspliceable pre-mRNA, and (3) transiently expressed I-SceI to create a DSB situation to study the effect of spliceable pre-mRNA on DNA repair. Based on our data, the RNA-edited pre-mRNA was used in cis for the DSB repair process, thereby converting the genomically encoded mutant reporter gene into an active reporter gene. Overexpression and knockdown of several cellular proteins were performed to delineate their role in this novel "RNA-mediated end joining" pathway.
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Affiliation(s)
- Lisa Tschage
- Institute of Pharmaceutical Biology, Goethe-University, Frankfurt am Main, Germany
| | - Eric Kowarz
- Institute of Pharmaceutical Biology, Goethe-University, Frankfurt am Main, Germany
| | - Rolf Marschalek
- Institute of Pharmaceutical Biology, Goethe-University, Frankfurt am Main, Germany
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28
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Oreper D, Klaeger S, Jhunjhunwala S, Delamarre L. The peptide woods are lovely, dark and deep: Hunting for novel cancer antigens. Semin Immunol 2023; 67:101758. [PMID: 37027981 DOI: 10.1016/j.smim.2023.101758] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/22/2023] [Accepted: 03/22/2023] [Indexed: 04/08/2023]
Abstract
Harnessing the patient's immune system to control a tumor is a proven avenue for cancer therapy. T cell therapies as well as therapeutic vaccines, which target specific antigens of interest, are being explored as treatments in conjunction with immune checkpoint blockade. For these therapies, selecting the best suited antigens is crucial. Most of the focus has thus far been on neoantigens that arise from tumor-specific somatic mutations. Although there is clear evidence that T-cell responses against mutated neoantigens are protective, the large majority of these mutations are not immunogenic. In addition, most somatic mutations are unique to each individual patient and their targeting requires the development of individualized approaches. Therefore, novel antigen types are needed to broaden the scope of such treatments. We review high throughput approaches for discovering novel tumor antigens and some of the key challenges associated with their detection, and discuss considerations when selecting tumor antigens to target in the clinic.
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Affiliation(s)
- Daniel Oreper
- Genentech, 1 DNA way, South San Francisco, 94080 CA, USA.
| | - Susan Klaeger
- Genentech, 1 DNA way, South San Francisco, 94080 CA, USA.
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29
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Mimoso CA, Adelman K. U1 snRNP increases RNA Pol II elongation rate to enable synthesis of long genes. Mol Cell 2023; 83:1264-1279.e10. [PMID: 36965480 PMCID: PMC10135401 DOI: 10.1016/j.molcel.2023.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/06/2023] [Accepted: 02/28/2023] [Indexed: 03/27/2023]
Abstract
The expansion of introns within mammalian genomes poses a challenge for the production of full-length messenger RNAs (mRNAs), with increasing evidence that these long AT-rich sequences present obstacles to transcription. Here, we investigate RNA polymerase II (RNAPII) elongation at high resolution in mammalian cells and demonstrate that RNAPII transcribes faster across introns. Moreover, we find that this acceleration requires the association of U1 snRNP (U1) with the elongation complex at 5' splice sites. The role of U1 to stimulate elongation rate through introns reduces the frequency of both premature termination and transcriptional arrest, thereby dramatically increasing RNA production. We further show that changes in RNAPII elongation rate due to AT content and U1 binding explain previous reports of pausing or termination at splice junctions and the edge of CpG islands. We propose that U1-mediated acceleration of elongation has evolved to mitigate the risks that long AT-rich introns pose to transcript completion.
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Affiliation(s)
- Claudia A Mimoso
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Karen Adelman
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Ludwig Center at Harvard, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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30
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de Felippes FF, Waterhouse PM. Plant terminators: the unsung heroes of gene expression. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:2239-2250. [PMID: 36477559 PMCID: PMC10082929 DOI: 10.1093/jxb/erac467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/25/2022] [Indexed: 06/06/2023]
Abstract
To be properly expressed, genes need to be accompanied by a terminator, a region downstream of the coding sequence that contains the information necessary for the maturation of the mRNA 3' end. The main event in this process is the addition of a poly(A) tail at the 3' end of the new transcript, a critical step in mRNA biology that has important consequences for the expression of genes. Here, we review the mechanism leading to cleavage and polyadenylation of newly transcribed mRNAs and how this process can affect the final levels of gene expression. We give special attention to an aspect often overlooked, the effect that different terminators can have on the expression of genes. We also discuss some exciting findings connecting the choice of terminator to the biogenesis of small RNAs, which are a central part of one of the most important mechanisms of regulation of gene expression in plants.
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Affiliation(s)
| | - Peter M Waterhouse
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- ARC Centre of Excellence for Plant Success in Nature & Agriculture, QUT, Brisbane, QLD, Australia
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31
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Pasternak AO, Berkhout B. HIV persistence: silence or resistance? Curr Opin Virol 2023; 59:101301. [PMID: 36805974 DOI: 10.1016/j.coviro.2023.101301] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/05/2022] [Accepted: 12/19/2022] [Indexed: 02/19/2023]
Abstract
Despite decades of suppressive antiretroviral therapy, human immunodeficiency virus (HIV) reservoirs in infected individuals persist and fuel viral rebound once therapy is interrupted. The persistence of viral reservoirs is the main obstacle to achieving HIV eradication or a long-term remission. The last decade has seen a profound change in our understanding of the mechanisms behind HIV persistence, which appears to be much more complex than originally assumed. In addition to the persistence of transcriptionally silent proviruses in a stable latent reservoir that is invisible to the immune system, HIV is increasingly recognized to persist by resistance to the immune clearance, which appears to play a surprisingly prominent role in shaping the reservoir. In this review, we discuss some emerging insights into the mechanisms of HIV persistence, as well as their implications for the development of strategies towards an HIV cure.
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Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands.
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
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32
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Welsh SA, Gardini A. Genomic regulation of transcription and RNA processing by the multitasking Integrator complex. Nat Rev Mol Cell Biol 2023; 24:204-220. [PMID: 36180603 PMCID: PMC9974566 DOI: 10.1038/s41580-022-00534-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2022] [Indexed: 11/09/2022]
Abstract
In higher eukaryotes, fine-tuned activation of protein-coding genes and many non-coding RNAs pivots around the regulated activity of RNA polymerase II (Pol II). The Integrator complex is the only Pol II-associated large multiprotein complex that is metazoan specific, and has therefore been understudied for years. Integrator comprises at least 14 subunits, which are grouped into distinct functional modules. The phosphodiesterase activity of the core catalytic module is co-transcriptionally directed against several RNA species, including long non-coding RNAs (lncRNAs), U small nuclear RNAs (U snRNAs), PIWI-interacting RNAs (piRNAs), enhancer RNAs and nascent pre-mRNAs. Processing of non-coding RNAs by Integrator is essential for their biogenesis, and at protein-coding genes, Integrator is a key modulator of Pol II promoter-proximal pausing and transcript elongation. Recent studies have identified an Integrator-specific serine/threonine-protein phosphatase 2A (PP2A) module, which targets Pol II and other components of the basal transcription machinery. In this Review, we discuss how the activity of Integrator regulates transcription, RNA processing, chromatin landscape and DNA repair. We also discuss the diverse roles of Integrator in development and tumorigenesis.
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33
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Hughes AL, Szczurek AT, Kelley JR, Lastuvkova A, Turberfield AH, Dimitrova E, Blackledge NP, Klose RJ. A CpG island-encoded mechanism protects genes from premature transcription termination. Nat Commun 2023; 14:726. [PMID: 36759609 PMCID: PMC9911701 DOI: 10.1038/s41467-023-36236-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Transcription must be tightly controlled to regulate gene expression and development. However, our understanding of the molecular mechanisms that influence transcription and how these are coordinated in cells to ensure normal gene expression remains rudimentary. Here, by dissecting the function of the SET1 chromatin-modifying complexes that bind to CpG island-associated gene promoters, we discover that they play a specific and essential role in enabling the expression of low to moderately transcribed genes. Counterintuitively, this effect can occur independently of SET1 complex histone-modifying activity and instead relies on an interaction with the RNA Polymerase II-binding protein WDR82. Unexpectedly, we discover that SET1 complexes enable gene expression by antagonising premature transcription termination by the ZC3H4/WDR82 complex at CpG island-associated genes. In contrast, at extragenic sites of transcription, which typically lack CpG islands and SET1 complex occupancy, we show that the activity of ZC3H4/WDR82 is unopposed. Therefore, we reveal a gene regulatory mechanism whereby CpG islands are bound by a protein complex that specifically protects genic transcripts from premature termination, effectively distinguishing genic from extragenic transcription and enabling normal gene expression.
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Affiliation(s)
- Amy L Hughes
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | | | - Anna Lastuvkova
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | | | | | - Robert J Klose
- Department of Biochemistry, University of Oxford, Oxford, UK.
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34
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Zhang S, Cooper JAL, Chong YS, Naveed A, Mayoh C, Jayatilleke N, Liu T, Amos S, Kobelke S, Marshall AC, Meers O, Choi YS, Bond CS, Fox AH. NONO enhances mRNA processing of super-enhancer-associated GATA2 and HAND2 genes in neuroblastoma. EMBO Rep 2023; 24:e54977. [PMID: 36416237 PMCID: PMC9900351 DOI: 10.15252/embr.202254977] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 11/02/2022] [Accepted: 11/07/2022] [Indexed: 11/24/2022] Open
Abstract
High-risk neuroblastoma patients have poor survival rates and require better therapeutic options. High expression of a multifunctional DNA and RNA-binding protein, NONO, in neuroblastoma is associated with poor patient outcome; however, there is little understanding of the mechanism of NONO-dependent oncogenic gene regulatory activity in neuroblastoma. Here, we used cell imaging, biochemical and genome-wide molecular analysis to reveal complex NONO-dependent regulation of gene expression. NONO forms RNA- and DNA-tethered condensates throughout the nucleus and undergoes phase separation in vitro, modulated by nucleic acid binding. CLIP analyses show that NONO mainly binds to the 5' end of pre-mRNAs and modulates pre-mRNA processing, dependent on its RNA-binding activity. NONO regulates super-enhancer-associated genes, including HAND2 and GATA2. Abrogating NONO RNA binding, or phase separation activity, results in decreased expression of HAND2 and GATA2. Thus, future development of agents that target RNA-binding activity of NONO may have therapeutic potential in this cancer context.
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Affiliation(s)
- Song Zhang
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Jack AL Cooper
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Yee Seng Chong
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Alina Naveed
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Chelsea Mayoh
- Children's Cancer Institute AustraliaRandwickNSWAustralia
- Centre for Childhood Cancer ResearchUNSW SydneyKensingtonNSWAustralia
- School of Women's and Children's HealthUNSW SydneyKensingtonNSWAustralia
| | - Nisitha Jayatilleke
- Children's Cancer Institute AustraliaRandwickNSWAustralia
- Centre for Childhood Cancer ResearchUNSW SydneyKensingtonNSWAustralia
| | - Tao Liu
- Children's Cancer Institute AustraliaRandwickNSWAustralia
- Centre for Childhood Cancer ResearchUNSW SydneyKensingtonNSWAustralia
| | - Sebastian Amos
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Simon Kobelke
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Andrew C Marshall
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Oliver Meers
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Yu Suk Choi
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Charles S Bond
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Archa H Fox
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
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35
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Wagner EJ, Tong L, Adelman K. Integrator is a global promoter-proximal termination complex. Mol Cell 2023; 83:416-427. [PMID: 36634676 PMCID: PMC10866050 DOI: 10.1016/j.molcel.2022.11.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 01/13/2023]
Abstract
Integrator is a metazoan-specific protein complex capable of inducing termination at all RNAPII-transcribed loci. Integrator recognizes paused, promoter-proximal RNAPII and drives premature termination using dual enzymatic activities: an endonuclease that cleaves nascent RNA and a protein phosphatase that removes stimulatory phosphorylation associated with RNAPII pause release and productive elongation. Recent breakthroughs in structural biology have revealed the overall architecture of Integrator and provided insights into how multiple Integrator modules are coordinated to elicit termination effectively. Furthermore, functional genomics and biochemical studies have unraveled how Integrator-mediated termination impacts protein-coding and noncoding loci. Here, we review the current knowledge about the assembly and activity of Integrator and describe the role of Integrator in gene regulation, highlighting the importance of this complex for human health.
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Affiliation(s)
- Eric J Wagner
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
| | - Karen Adelman
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
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36
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Xie J, Libri D, Porrua O. Mechanisms of eukaryotic transcription termination at a glance. J Cell Sci 2023; 136:286227. [PMID: 36594557 DOI: 10.1242/jcs.259873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transcription termination is the final step of a transcription cycle, which induces the release of the transcript at the termination site and allows the recycling of the polymerase for the next round of transcription. Timely transcription termination is critical for avoiding interferences between neighbouring transcription units as well as conflicts between transcribing RNA polymerases (RNAPs) and other DNA-associated processes, such as replication or DNA repair. Understanding the mechanisms by which the very stable transcription elongation complex is dismantled is essential for appreciating how physiological gene expression is maintained and also how concurrent processes that occur synchronously on the DNA are coordinated. Although the strategies employed by the different classes of eukaryotic RNAPs are traditionally considered to be different, novel findings point to interesting commonalities. In this Cell Science at a Glance and the accompanying poster, we review the current understanding about the mechanisms of transcription termination by the three eukaryotic RNAPs.
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Affiliation(s)
- Juanjuan Xie
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Domenico Libri
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Odil Porrua
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
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37
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The PNUTS-PP1 complex acts as an intrinsic barrier to herpesvirus KSHV gene expression and replication. Nat Commun 2022; 13:7447. [PMID: 36460671 PMCID: PMC9718767 DOI: 10.1038/s41467-022-35268-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 11/24/2022] [Indexed: 12/03/2022] Open
Abstract
Control of RNA Polymerase II (pol II) elongation is a critical component of gene expression in mammalian cells. The PNUTS-PP1 complex controls elongation rates, slowing pol II after polyadenylation sites to promote termination. The Kaposi's sarcoma-associated herpesvirus (KSHV) co-opts pol II to express its genes, but little is known about its regulation of pol II elongation. We identified PNUTS as a suppressor of a KSHV reporter gene in a genome-wide CRISPR screen. PNUTS depletion enhances global KSHV gene expression and overall viral replication. Mechanistically, PNUTS requires PP1 interaction, binds viral RNAs downstream of polyadenylation sites, and restricts transcription readthrough of viral genes. Surprisingly, PNUTS also represses productive elongation at the 5´ ends of the KSHV reporter and the KSHV T1.4 RNA. From these data, we conclude that PNUTS' activity constitutes an intrinsic barrier to KSHV replication likely by suppressing pol II elongation at promoter-proximal regions.
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Sabath K, Jonas S. Take a break: Transcription regulation and RNA processing by the Integrator complex. Curr Opin Struct Biol 2022; 77:102443. [PMID: 36088798 DOI: 10.1016/j.sbi.2022.102443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 07/16/2022] [Accepted: 07/19/2022] [Indexed: 12/14/2022]
Abstract
The metazoan-specific Integrator complex is a >1.5 MDa machinery that interacts with RNA polymerase II (RNAP2) to attenuate coding gene transcription by early termination close to transcription start sites. Using a highly related mechanism, Integrator also performs the initial 3'-end processing step for many non-coding RNAs. Its transcription regulation functions are essential for cell differentiation and response to external stimuli. Recent studies revealed that the complex incorporates phosphatase PP2A to counteract phosphorylation reactions that are required for transcription elongation. Structures of Integrator bound to RNAP2 explain the basis for its recruitment to promoter proximal RNAP2 by recognition of its paused state. Furthermore, several studies indicate that Integrator's cleavage activity is regulated at multiple levels through activators, modifications, and small molecules.
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Affiliation(s)
- Kevin Sabath
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Switzerland
| | - Stefanie Jonas
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Switzerland.
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Stein CB, Field AR, Mimoso CA, Zhao C, Huang KL, Wagner EJ, Adelman K. Integrator endonuclease drives promoter-proximal termination at all RNA polymerase II-transcribed loci. Mol Cell 2022; 82:4232-4245.e11. [PMID: 36309014 PMCID: PMC9680917 DOI: 10.1016/j.molcel.2022.10.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 08/28/2022] [Accepted: 10/04/2022] [Indexed: 11/07/2022]
Abstract
RNA polymerase II (RNAPII) pausing in early elongation is critical for gene regulation. Paused RNAPII can be released into productive elongation by the kinase P-TEFb or targeted for premature termination by the Integrator complex. Integrator comprises endonuclease and phosphatase activities, driving termination by cleavage of nascent RNA and removal of stimulatory phosphorylation. We generated a degron system for rapid Integrator endonuclease (INTS11) depletion to probe the direct consequences of Integrator-mediated RNA cleavage. Degradation of INTS11 elicits nearly universal increases in active early elongation complexes. However, these RNAPII complexes fail to achieve optimal elongation rates and exhibit persistent Integrator phosphatase activity. Thus, only short transcripts are significantly upregulated following INTS11 loss, including transcription factors, signaling regulators, and non-coding RNAs. We propose a uniform molecular function for INTS11 across all RNAPII-transcribed loci, with differential effects on particular genes, pathways, or RNA biotypes reflective of transcript lengths rather than specificity of Integrator activity.
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Affiliation(s)
- Chad B Stein
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew R Field
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Ludwig Center at Harvard, Boston, MA 02115, USA
| | - Claudia A Mimoso
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - ChenCheng Zhao
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Kai-Lieh Huang
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Eric J Wagner
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Karen Adelman
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Ludwig Center at Harvard, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA.
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Hunt AG. Review: Mechanisms underlying alternative polyadenylation in plants - looking in the right places. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 324:111430. [PMID: 36007628 DOI: 10.1016/j.plantsci.2022.111430] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 08/01/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Recent years have seen an explosion of interest in the subject of alternative polyadenylation in plants. Connections between the polyadenylation complex and numerous developmental and stress responses are well-established. However, those that link stimuli with the functioning of the polyadenylation complex are less well understood. To this end, it is imperative to clearly delineate the roles of the polyadenylation complex in both plant growth AND alternative polyadenylation. It is also necessary to understand the ways by which other molecular processes may contribute to alternative polyadenylation. This review discusses these issues, with a focus on instances that reveal mechanisms by which mRNA polyadenylation may be regulated. Insights from from characterizations of mutants affected in the polyadenylation complex are discussed, as are the limitations of such characterizations when it comes to teasing out cause and effect. These limitations encourage explorations to other processes that are beyond the core polyadenylation complex. Two such processes that sculpt the plant transcriptome - transcription termination and the epigenetic control of transposon activity - also contribute to regulated poly(A) site choice. These subjects define "the right places" - molecular mechanisms that contribute to the wide-ranging control of gene expression via mRNA polyadenylation.
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Affiliation(s)
- Arthur G Hunt
- Department of Plant and Soil Sciences, University of Kentucky, 301A Plant Science Building, 1405 Veterans Road, Lexington, KY 40546-0312, USA.
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41
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Amodeo ME, Mitchell SPC, Pavan V, Kuehner JN. RNA polymerase II transcription attenuation at the yeast DNA repair gene DEF1 is biologically significant and dependent on the Hrp1 RNA-recognition motif. G3 (BETHESDA, MD.) 2022; 13:6782960. [PMID: 36315099 PMCID: PMC9836349 DOI: 10.1093/g3journal/jkac292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 10/27/2022] [Indexed: 11/05/2022]
Abstract
Premature transcription termination (i.e. attenuation) is a potent gene regulatory mechanism that represses mRNA synthesis. Attenuation of RNA polymerase II is more prevalent than once appreciated, targeting 10-15% of mRNA genes in yeast through higher eukaryotes, but its significance and mechanism remain obscure. In the yeast Saccharomyces cerevisiae, polymerase II attenuation was initially shown to rely on Nrd1-Nab3-Sen1 termination, but more recently our laboratory characterized a hybrid termination pathway involving Hrp1, an RNA-binding protein in the 3'-end cleavage factor. One of the hybrid attenuation gene targets is DEF1, which encodes a repair protein that promotes degradation of polymerase II stalled at DNA lesions. In this study, we characterized the chromosomal DEF1 attenuator and the functional role of Hrp1. DEF1 attenuator mutants overexpressed Def1 mRNA and protein, exacerbated polymerase II degradation, and hindered cell growth, supporting a biologically significant DEF1 attenuator function. Using an auxin-induced Hrp1 depletion system, we identified new Hrp1-dependent attenuators in MNR2, SNG1, and RAD3 genes. An hrp1-5 mutant (L205S) known to impair binding to cleavage factor protein Rna14 also disrupted attenuation, but surprisingly no widespread defect was observed for an hrp1-1 mutant (K160E) located in the RNA-recognition motif. We designed a new RNA recognition motif mutant (hrp1-F162W) that altered a highly conserved residue and was lethal in single copy. In a heterozygous strain, hrp1-F162W exhibited dominant-negative readthrough defects at several gene attenuators. Overall, our results expand the hybrid RNA polymerase II termination pathway, confirming that Hrp1-dependent attenuation controls multiple yeast genes and may function through binding cleavage factor proteins and/or RNA.
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Affiliation(s)
- Maria E Amodeo
- Department of Cancer Immunology & Virology, Dana Farber Cancer Institute, Boston, MA 02215, USA
| | - Shane P C Mitchell
- Alzheimer Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
| | - Vincent Pavan
- Department of Biology, Emmanuel College, Boston, MA 02115, USA
| | - Jason N Kuehner
- Corresponding author: Department of Biology, Emmanuel College, 400 The Fenway, Boston, MA 02115, USA.
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42
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Li Y, Li J, Wang J, Zhang S, Giles K, Prakash TP, Rigo F, Napierala JS, Napierala M. Premature transcription termination at the expanded GAA repeats and aberrant alternative polyadenylation contributes to the Frataxin transcriptional deficit in Friedreich's ataxia. Hum Mol Genet 2022; 31:3539-3557. [PMID: 35708503 PMCID: PMC9558844 DOI: 10.1093/hmg/ddac134] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/12/2022] [Accepted: 06/05/2022] [Indexed: 11/18/2022] Open
Abstract
Frataxin deficiency in Friedreich's ataxia results from transcriptional downregulation of the FXN gene caused by expansion of the intronic trinucleotide guanine-adenine-adenine (GAA) repeats. We used multiple transcriptomic approaches to determine the molecular mechanism of transcription inhibition caused by long GAAs. We uncovered that transcription of FXN in patient cells is prematurely terminated upstream of the expanded repeats leading to the formation of a novel, truncated and stable RNA. This FXN early terminated transcript (FXN-ett) undergoes alternative, non-productive splicing and does not contribute to the synthesis of functional frataxin. The level the FXN-ett RNA directly correlates with the length of the longer of the two expanded GAA tracts. Targeting GAAs with antisense oligonucleotides or excision of the repeats eliminates the transcription impediment, diminishes expression of the aberrant FXN-ett, while increasing levels of FXN mRNA and frataxin. Non-productive transcription may represent a common phenomenon and attractive therapeutic target in diseases caused by repeat-mediated transcription aberrations.
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Affiliation(s)
- Yanjie Li
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Jixue Li
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Jun Wang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Siyuan Zhang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Keith Giles
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Thazha P Prakash
- Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Frank Rigo
- Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Jill S Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
- Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
- Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
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43
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Cortazar MA, Erickson B, Fong N, Pradhan SJ, Ntini E, Bentley DL. Xrn2 substrate mapping identifies torpedo loading sites and extensive premature termination of RNA pol II transcription. Genes Dev 2022; 36:1062-1078. [PMID: 36396340 PMCID: PMC9744234 DOI: 10.1101/gad.350004.122] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/31/2022] [Indexed: 11/19/2022]
Abstract
The exonuclease torpedo Xrn2 loads onto nascent RNA 5'-PO4 ends and chases down pol II to promote termination downstream from polyA sites. We report that Xrn2 is recruited to preinitiation complexes and "travels" to 3' ends of genes. Mapping of 5'-PO4 ends in nascent RNA identified Xrn2 loading sites stabilized by an active site mutant, Xrn2(D235A). Xrn2 loading sites are approximately two to 20 bases downstream from where CPSF73 cleaves at polyA sites and histone 3' ends. We propose that processing of all mRNA 3' ends comprises cleavage and limited 5'-3' trimming by CPSF73, followed by handoff to Xrn2. A similar handoff occurs at tRNA 3' ends, where cotranscriptional RNase Z cleavage generates novel Xrn2 substrates. Exonuclease-dead Xrn2 increased transcription in 3' flanking regions by inhibiting polyA site-dependent termination. Surprisingly, the mutant Xrn2 also rescued transcription in promoter-proximal regions to the same extent as in 3' flanking regions. eNET-seq revealed Xrn2-mediated degradation of sense and antisense nascent RNA within a few bases of the TSS, where 5'-PO4 ends may be generated by decapping or endonucleolytic cleavage. These results suggest that a major fraction of pol II complexes terminates prematurely close to the start site under normal conditions by an Xrn2-mediated torpedo mechanism.
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Affiliation(s)
- Michael A. Cortazar
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Benjamin Erickson
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Nova Fong
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Sarala J. Pradhan
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Evgenia Ntini
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas (FORTH), Heraklion GR-70013, Greece
| | - David L. Bentley
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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Gosselin MRF, Mournetas V, Borczyk M, Verma S, Occhipinti A, Róg J, Bozycki L, Korostynski M, Robson SC, Angione C, Pinset C, Gorecki DC. Loss of full-length dystrophin expression results in major cell-autonomous abnormalities in proliferating myoblasts. eLife 2022; 11:e75521. [PMID: 36164827 PMCID: PMC9514850 DOI: 10.7554/elife.75521] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 09/02/2022] [Indexed: 12/05/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) affects myofibers and muscle stem cells, causing progressive muscle degeneration and repair defects. It was unknown whether dystrophic myoblasts-the effector cells of muscle growth and regeneration-are affected. Using transcriptomic, genome-scale metabolic modelling and functional analyses, we demonstrate, for the first time, convergent abnormalities in primary mouse and human dystrophic myoblasts. In Dmdmdx myoblasts lacking full-length dystrophin, the expression of 170 genes was significantly altered. Myod1 and key genes controlled by MyoD (Myog, Mymk, Mymx, epigenetic regulators, ECM interactors, calcium signalling and fibrosis genes) were significantly downregulated. Gene ontology analysis indicated enrichment in genes involved in muscle development and function. Functionally, we found increased myoblast proliferation, reduced chemotaxis and accelerated differentiation, which are all essential for myoregeneration. The defects were caused by the loss of expression of full-length dystrophin, as similar and not exacerbated alterations were observed in dystrophin-null Dmdmdx-βgeo myoblasts. Corresponding abnormalities were identified in human DMD primary myoblasts and a dystrophic mouse muscle cell line, confirming the cross-species and cell-autonomous nature of these defects. The genome-scale metabolic analysis in human DMD myoblasts showed alterations in the rate of glycolysis/gluconeogenesis, leukotriene metabolism, and mitochondrial beta-oxidation of various fatty acids. These results reveal the disease continuum: DMD defects in satellite cells, the myoblast dysfunction affecting muscle regeneration, which is insufficient to counteract muscle loss due to myofiber instability. Contrary to the established belief, our data demonstrate that DMD abnormalities occur in myoblasts, making these cells a novel therapeutic target for the treatment of this lethal disease.
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Affiliation(s)
- Maxime RF Gosselin
- School of Pharmacy and Biomedical Sciences, University of PortsmouthPortsmouthUnited Kingdom
| | | | - Malgorzata Borczyk
- Laboratory of Pharmacogenomics, Maj Institute of Pharmacology PASKrakowPoland
| | - Suraj Verma
- School of Computing, Engineering and Digital Technologies, Teesside UniversityMiddlesbroughUnited Kingdom
| | - Annalisa Occhipinti
- School of Computing, Engineering and Digital Technologies, Teesside UniversityMiddlesbroughUnited Kingdom
| | - Justyna Róg
- School of Pharmacy and Biomedical Sciences, University of PortsmouthPortsmouthUnited Kingdom
- Laboratory of Cellular Metabolism, Nencki Institute of Experimental BiologyWarsawPoland
| | - Lukasz Bozycki
- School of Pharmacy and Biomedical Sciences, University of PortsmouthPortsmouthUnited Kingdom
- Laboratory of Cellular Metabolism, Nencki Institute of Experimental BiologyWarsawPoland
| | - Michal Korostynski
- Laboratory of Pharmacogenomics, Maj Institute of Pharmacology PASKrakowPoland
| | - Samuel C Robson
- School of Pharmacy and Biomedical Sciences, University of PortsmouthPortsmouthUnited Kingdom
- Centre for Enzyme Innovation, University of PortsmouthPortsmouthUnited Kingdom
| | - Claudio Angione
- School of Computing, Engineering and Digital Technologies, Teesside UniversityMiddlesbroughUnited Kingdom
| | | | - Dariusz C Gorecki
- School of Pharmacy and Biomedical Sciences, University of PortsmouthPortsmouthUnited Kingdom
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Li Y, Huang J, Zhu J, Bao L, Wang H, Jiang Y, Tian K, Wang R, Zheng H, Duan W, Lai W, Yi X, Zhu Y, Guo T, Ji X. Targeted protein degradation reveals RNA Pol II heterogeneity and functional diversity. Mol Cell 2022; 82:3943-3959.e11. [PMID: 36113479 DOI: 10.1016/j.molcel.2022.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/14/2022] [Accepted: 08/18/2022] [Indexed: 10/14/2022]
Abstract
RNA polymerase II (RNA Pol II) subunits are thought to be involved in various transcription-associated processes, but it is unclear whether they play different regulatory roles in modulating gene expression. Here, we performed nascent and mature transcript sequencing after the acute degradation of 12 mammalian RNA Pol II subunits and profiled their genomic binding sites and protein interactomes to dissect their molecular functions. We found that RNA Pol II subunits contribute differently to RNA Pol II cellular localization and transcription processes and preferentially regulate RNA processing (such as RNA splicing and 3' end maturation). Genes sensitive to the depletion of different RNA Pol II subunits tend to be involved in diverse biological functions and show different RNA half-lives. Sequences, associated protein factors, and RNA structures are correlated with RNA Pol II subunit-mediated differential gene expression. These findings collectively suggest that the heterogeneity of RNA Pol II and different genes appear to depend on some of the subunits.
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Affiliation(s)
- Yuanjun Li
- 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
| | - Junyi Zhu
- 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
| | - Lijun Bao
- 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
| | - Yongpeng Jiang
- 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
| | - 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
| | - Haonan Zheng
- 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
| | - WenJia Duan
- 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
| | - Weifeng Lai
- 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
| | - Xiao Yi
- Westlake 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; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Yi Zhu
- Westlake 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; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Tiannan Guo
- Westlake 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; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, 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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46
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Sawarkar R. Transcriptional lockdown during acute proteotoxic stress. Trends Biochem Sci 2022; 47:660-672. [PMID: 35487807 PMCID: PMC9041648 DOI: 10.1016/j.tibs.2022.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 03/20/2022] [Accepted: 03/31/2022] [Indexed: 12/02/2022]
Abstract
Cells experiencing proteotoxic stress downregulate the expression of thousands of active genes and upregulate a few stress-response genes. The strategy of downregulating gene expression has conceptual parallels with general lockdown in the global response to the coronavirus disease 2019 (COVID-19) pandemic. The mechanistic details of global transcriptional downregulation of genes, termed stress-induced transcriptional attenuation (SITA), are only beginning to emerge. The reduction in RNA and protein production during stress may spare proteostasis capacity, allowing cells to divert resources to control stress-induced damage. Given the relevance of translational downregulation in a broad variety of diseases, the role of SITA in diseases caused by proteotoxicity should be investigated in future, paving the way for potential novel therapeutics.
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Affiliation(s)
- Ritwick Sawarkar
- Medical Research Council (MRC), University of Cambridge, Cambridge, UK.
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47
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Elton TS, Hernandez VA, Carvajal-Moreno J, Wang X, Ipinmoroti D, Yalowich JC. Intronic Polyadenylation in Acquired Cancer Drug Resistance Circumvented by Utilizing CRISPR/Cas9 with Homology-Directed Repair: The Tale of Human DNA Topoisomerase IIα. Cancers (Basel) 2022; 14:cancers14133148. [PMID: 35804920 PMCID: PMC9265003 DOI: 10.3390/cancers14133148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 12/02/2022] Open
Abstract
Simple Summary DNA topoisomerase IIα (170 kDa, TOP2α/170) resolves nucleic acid topological entanglements by generating transient double-strand DNA breaks. TOP2α inhibitors/poisons stabilize TOP2α-DNA covalent complexes resulting in persistent DNA damage and are frequently utilized to treat a variety of cancers. Acquired resistance to these chemotherapeutic agents is often associated with decreased TOP2α/170 expression levels. Studies have demonstrated that a reduction in TOP2α/170 results from a type of alternative polyadenylation designated intronic polyadenylation (IPA). As a consequence of IPA, variant TOP2α mRNA transcripts have been characterized that have resulted in the translation of C-terminal truncated TOP2α isoforms with altered biological activities. In this paper, an example is discussed where circumvention of acquired TOP2α-mediated drug resistance was achieved by utilizing CRISPR/Cas9 specific gene editing of an exon/intron boundary through homology directed repair (HDR) to reduce TOP2α IPA. These results illustrate the therapeutic potential of CRISPR/Cas9/HDR to impact drug resistance associated with aberrant IPA. Abstract Intronic polyadenylation (IPA) plays a critical role in malignant transformation, development, progression, and cancer chemoresistance by contributing to transcriptome/proteome alterations. DNA topoisomerase IIα (170 kDa, TOP2α/170) is an established clinical target for anticancer agents whose efficacy is compromised by drug resistance often associated with a reduction of nuclear TOP2α/170 levels. In leukemia cell lines with acquired resistance to TOP2α-targeted drugs and reduced TOP2α/170 expression, variant TOP2α mRNA transcripts have been reported due to IPA that resulted in the translation of C-terminal truncated isoforms with altered nuclear-cytoplasmic distribution or heterodimerization with wild-type TOP2α/170. This review provides an overview of the various mechanisms regulating pre-mRNA processing and alternative polyadenylation, as well as the utilization of CRISPR/Cas9 specific gene editing through homology directed repair (HDR) to decrease IPA when splice sites are intrinsically weak or potentially mutated. The specific case of TOP2α exon 19/intron 19 splice site editing is discussed in etoposide-resistant human leukemia K562 cells as a tractable strategy to circumvent acquired TOP2α-mediated drug resistance. This example supports the importance of aberrant IPA in acquired drug resistance to TOP2α-targeted drugs. In addition, these results demonstrate the therapeutic potential of CRISPR/Cas9/HDR to impact drug resistance associated with aberrant splicing/polyadenylation.
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48
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Cugusi S, Mitter R, Kelly GP, Walker J, Han Z, Pisano P, Wierer M, Stewart A, Svejstrup JQ. Heat shock induces premature transcript termination and reconfigures the human transcriptome. Mol Cell 2022; 82:1573-1588.e10. [PMID: 35114099 PMCID: PMC9098121 DOI: 10.1016/j.molcel.2022.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/30/2021] [Accepted: 01/07/2022] [Indexed: 12/14/2022]
Abstract
The heat shock (HS) response involves rapid induction of HS genes, whereas transcriptional repression is established more slowly at most other genes. Previous data suggested that such repression results from inhibition of RNA polymerase II (RNAPII) pause release, but here, we show that HS strongly affects other phases of the transcription cycle. Intriguingly, while elongation rates increase upon HS, processivity markedly decreases, so that RNAPII frequently fails to reach the end of genes. Indeed, HS results in widespread premature transcript termination at cryptic, intronic polyadenylation (IPA) sites near gene 5'-ends, likely via inhibition of U1 telescripting. This results in dramatic reconfiguration of the human transcriptome with production of new, previously unannotated, short mRNAs that accumulate in the nucleus. Together, these results shed new light on the basic transcription mechanisms induced by growth at elevated temperature and show that a genome-wide shift toward usage of IPA sites can occur under physiological conditions.
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Affiliation(s)
- Simona Cugusi
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Richard Mitter
- Bioinformatics and Biostatistics, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Gavin P Kelly
- Bioinformatics and Biostatistics, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jane Walker
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Zhong Han
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Cellular and Molecular Medicine, Panum Institute, Blegdamsvej 3B, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Paola Pisano
- Proteomics Research Infrastructure, Panum Institute, Blegdamsvej 3B, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Michael Wierer
- Proteomics Research Infrastructure, Panum Institute, Blegdamsvej 3B, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Aengus Stewart
- Bioinformatics and Biostatistics, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jesper Q Svejstrup
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Cellular and Molecular Medicine, Panum Institute, Blegdamsvej 3B, University of Copenhagen, 2200 Copenhagen N, Denmark.
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49
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Gdula MR, Kopczyńska M, Saha U, Kamieniarz-Gdula K. CLP1-dependent premature transcription termination opposes neurodegeneration. Neuron 2022; 110:1277-1280. [PMID: 35447096 DOI: 10.1016/j.neuron.2022.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Usage of alternative mRNA 3' ends has profound functional consequences, particularly in the nervous system. In this issue of Neuron, LaForce et al. (2022) dissect the effect of CLP1 on mRNA 3' end diversity in motor neuron models of neurodegeneration.
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Affiliation(s)
- Michal R Gdula
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614 Poznań, Poland; Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Magda Kopczyńska
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614 Poznań, Poland; Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Upasana Saha
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614 Poznań, Poland; Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Kinga Kamieniarz-Gdula
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614 Poznań, Poland; Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
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50
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Jobbins AM, Haberman N, Artigas N, Amourda C, Paterson HAB, Yu S, Blackford SJI, Montoya A, Dore M, Wang YF, Sardini A, Cebola I, Zuber J, Rashid ST, Lenhard B, Vernia S. Dysregulated RNA polyadenylation contributes to metabolic impairment in non-alcoholic fatty liver disease. Nucleic Acids Res 2022; 50:3379-3393. [PMID: 35293570 PMCID: PMC8989518 DOI: 10.1093/nar/gkac165] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 02/16/2022] [Accepted: 03/09/2022] [Indexed: 11/19/2022] Open
Abstract
Pre-mRNA processing is an essential mechanism for the generation of mature mRNA and the regulation of gene expression in eukaryotic cells. While defects in pre-mRNA processing have been implicated in a number of diseases their involvement in metabolic pathologies is still unclear. Here, we show that both alternative splicing and alternative polyadenylation, two major steps in pre-mRNA processing, are significantly altered in non-alcoholic fatty liver disease (NAFLD). Moreover, we find that Serine and Arginine Rich Splicing Factor 10 (SRSF10) binding is enriched adjacent to consensus polyadenylation motifs and its expression is significantly decreased in NAFLD, suggesting a role mediating pre-mRNA dysregulation in this condition. Consistently, inactivation of SRSF10 in mouse and human hepatocytes in vitro, and in mouse liver in vivo, was found to dysregulate polyadenylation of key metabolic genes such as peroxisome proliferator-activated receptor alpha (PPARA) and exacerbate diet-induced metabolic dysfunction. Collectively our work implicates dysregulated pre-mRNA polyadenylation in obesity-induced liver disease and uncovers a novel role for SRSF10 in this process.
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Affiliation(s)
- Andrew M Jobbins
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Nejc Haberman
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Natalia Artigas
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Christopher Amourda
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Helen A B Paterson
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Sijia Yu
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Samuel J I Blackford
- Department of Metabolism, Digestion & Reproduction, Imperial College London, London W12 0NN, UK
| | - Alex Montoya
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Marian Dore
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Yi-Fang Wang
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Alessandro Sardini
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Inês Cebola
- Section of Genetics and Genomics, Department of Metabolism, Digestion & Reproduction, Imperial College London, London W12 0NN, UK
| | - Johannes Zuber
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Sheikh Tamir Rashid
- Department of Metabolism, Digestion & Reproduction, Imperial College London, London W12 0NN, UK
| | - Boris Lenhard
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Santiago Vernia
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
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