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Mo C, Wei N, Li T, Ahmed Bhat M, Mohammadi M, Kuang C. CDK9 inhibitors for the treatment of solid tumors. Biochem Pharmacol 2024:116470. [PMID: 39127153 DOI: 10.1016/j.bcp.2024.116470] [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: 05/14/2024] [Revised: 08/04/2024] [Accepted: 08/05/2024] [Indexed: 08/12/2024]
Abstract
Cyclin-dependent kinase 9 (CDK9) regulates mRNA transcription by promoting RNA Pol II elongation. CDK9 is now emerging as a potential therapeutic target for cancer, since its overexpression has been found to correlate with cancer development and worse clinical outcomes. While much work on CDK9 inhibition has focused on hematologic malignancies, the role of this cancer driver in solid tumors is starting to come into focus. Many solid cancers also overexpress CDK9 and depend on its activity to promote downstream oncogenic signaling pathways. In this review, we summarize the latest knowledge of CDK9 biology in solid tumors and the studies of small molecule CDK9 inhibitors. We discuss the results of the latest clinical trials of CDK9 inhibitors in solid tumors, with a focus on key issues to consider for improving the therapeutic impact of this drug class.
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Affiliation(s)
- Christiana Mo
- Department of Oncology, Montefiore Einstein, Bronx, NY, USA; Montefiore Einstein Comprehensive Cancer Center, Bronx, NY, USA
| | - Ning Wei
- Department of Oncology, Montefiore Einstein, Bronx, NY, USA; Montefiore Einstein Comprehensive Cancer Center, Bronx, NY, USA; Department of Molecular Pharmacology, Montefiore Einstein, Bronx, NY, USA
| | - Terence Li
- Department of Oncology, Montefiore Einstein, Bronx, NY, USA; Montefiore Einstein Comprehensive Cancer Center, Bronx, NY, USA; Department of Molecular Pharmacology, Montefiore Einstein, Bronx, NY, USA
| | - Muzaffer Ahmed Bhat
- Department of Oncology, Montefiore Einstein, Bronx, NY, USA; Montefiore Einstein Comprehensive Cancer Center, Bronx, NY, USA; Department of Molecular Pharmacology, Montefiore Einstein, Bronx, NY, USA
| | - Mahshid Mohammadi
- Department of Oncology, Montefiore Einstein, Bronx, NY, USA; Montefiore Einstein Comprehensive Cancer Center, Bronx, NY, USA; Department of Molecular Pharmacology, Montefiore Einstein, Bronx, NY, USA
| | - Chaoyuan Kuang
- Department of Oncology, Montefiore Einstein, Bronx, NY, USA; Montefiore Einstein Comprehensive Cancer Center, Bronx, NY, USA; Department of Molecular Pharmacology, Montefiore Einstein, Bronx, NY, USA.
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2
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Zhao Y, Ma X, Ye C, Li W, Pajdzik K, Dai Q, Sun HL, He C. Pseudouridine Detection and Quantification Using Bisulfite Incorporation Hindered Ligation. ACS Chem Biol 2024. [PMID: 39014961 DOI: 10.1021/acschembio.4c00387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Pseudouridine (Ψ) is a widespread RNA modification found in various RNA species, including rRNA, tRNA, snRNA, mRNA, and long noncoding RNA (lncRNA). Understanding the function of Ψ in these RNA types requires a robust method for the detection and quantification of the Ψ level at single-nucleotide resolution. A previously used method utilizes Ψ labeling by N-cyclohexyl-N'-β-(4-methylmorpholinium)ethylcarbodiimide (CMC). The quantification of Ψ is based on the stop ratio after reverse transcription. However, the use of CMC followed by strong alkaline treatment causes severe RNA degradation, often requiring a large amount of RNA. The removal of CMC and recovery of RNA by ethanol precipitation are also time-consuming. Here, we introduce a Bisulfite Incorporation Hindered ligation-based method (BIHIND), which can detect and quantify Ψ sites on rRNA, mRNA, and noncoding RNA. BIHIND can be coupled with quantitative PCR (BIHIND-qPCR) for quantitative detection of Ψ fraction at individual modification sites, as well as with next-generation sequencing (BIHIND-seq) for high-throughput sequencing of Ψ without requiring reverse transcription. We validated the robustness of BIHIND with the elucidation of Ψ dynamics following pseudouridine synthase depletion.
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Affiliation(s)
- Yutao Zhao
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Xinyuan Ma
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Chang Ye
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Wenlong Li
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Kinga Pajdzik
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Qing Dai
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Hui-Lung Sun
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Chuan He
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United States
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3
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Donnio LM, Giglia-Mari G. Keep calm and reboot - how cells restart transcription after DNA damage and DNA repair. FEBS Lett 2024. [PMID: 38991979 DOI: 10.1002/1873-3468.14964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/12/2024] [Accepted: 04/21/2024] [Indexed: 07/13/2024]
Abstract
The effects of genotoxic agents on DNA and the processes involved in their removal have been thoroughly studied; however, very little is known about the mechanisms governing the reinstatement of cellular activities after DNA repair, despite restoration of the damage-induced block of transcription being essential for cell survival. In addition to impeding transcription, DNA lesions have the potential to disrupt the precise positioning of chromatin domains within the nucleus and alter the meticulously organized architecture of the nucleolus. Alongside the necessity of resuming transcription mediated by RNA polymerase 1 and 2 transcription, it is crucial to restore the structure of the nucleolus to facilitate optimal ribosome biogenesis and ensure efficient and error-free translation. Here, we examine the current understanding of how transcriptional activity from RNA polymerase 2 is reinstated following DNA repair completion and explore the mechanisms involved in reassembling the nucleolus to safeguard the correct progression of cellular functions. Given the lack of information on this vital function, this Review seeks to inspire researchers to explore deeper into this specific subject and offers essential suggestions on how to investigate this complex and nearly unexplored process further.
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Affiliation(s)
- Lise-Marie Donnio
- Institut NeuroMyoGène-Pathophysiology and Genetics of Neuron and Muscle (INMG_PGNM), CNRS UMR 5261, INSERM U1315, Université Claude Bernard Lyon 1, Lyon, 69008, France
| | - Giuseppina Giglia-Mari
- Institut NeuroMyoGène-Pathophysiology and Genetics of Neuron and Muscle (INMG_PGNM), CNRS UMR 5261, INSERM U1315, Université Claude Bernard Lyon 1, Lyon, 69008, France
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4
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D'Orso I. The HIV-1 Transcriptional Program: From Initiation to Elongation Control. J Mol Biol 2024:168690. [PMID: 38936695 DOI: 10.1016/j.jmb.2024.168690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/29/2024]
Abstract
A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
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Affiliation(s)
- Iván D'Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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5
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Zhang Z, Xu J, Liu J, Wang J, Lei L. SEC: A core hub during cell fate alteration. FASEB J 2024; 38:e23680. [PMID: 38758186 DOI: 10.1096/fj.202400514r] [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: 03/06/2024] [Revised: 04/18/2024] [Accepted: 05/07/2024] [Indexed: 05/18/2024]
Abstract
Pol II pause release is a rate-limiting step in gene transcription, influencing various cell fate alterations. Numerous proteins orchestrate Pol II pause release, thereby playing pivotal roles in the intricate process of cellular fate modulation. Super elongation complex (SEC), a large assembly comprising diverse protein components, has garnered attention due to its emerging significance in orchestrating physiological and pathological cellular identity changes by regulating the transcription of crucial genes. Consequently, SEC emerges as a noteworthy functional complex capable of modulating cell fate alterations. Therefore, a comprehensive review is warranted to systematically summarize the core roles of SEC in different types of cell fate alterations. This review focuses on elucidating the current understanding of the structural and functional basis of SEC. Additionally, we discuss the intricate regulatory mechanisms governing SEC in various models of cell fate alteration, encompassing both physiological and pathological contexts. Furthermore, leveraging the existing knowledge of SEC, we propose some insightful directions for future research, aiming to enhance our mechanistic and functional comprehension of SEC within the diverse landscape of cell fate alterations.
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Affiliation(s)
- Zhijing Zhang
- College of Life Science, Northeast Agricultural University, Harbin, Heilongjiang Province, China
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jingyi Xu
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jiqiang Liu
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jiaqiang Wang
- College of Life Science, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - Lei Lei
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
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6
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Vaňková Hausnerová V, Shoman M, Kumar D, Schwarz M, Modrák M, Jirát Matějčková J, Mikesková E, Neva S, Herrmannová A, Šiková M, Halada P, Novotná I, Pajer P, Valášek LS, Převorovský M, Krásný L, Hnilicová J. RIP-seq reveals RNAs that interact with RNA polymerase and primary sigma factors in bacteria. Nucleic Acids Res 2024; 52:4604-4626. [PMID: 38348908 PMCID: PMC11077062 DOI: 10.1093/nar/gkae081] [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: 07/21/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 05/09/2024] Open
Abstract
Bacteria have evolved structured RNAs that can associate with RNA polymerase (RNAP). Two of them have been known so far-6S RNA and Ms1 RNA but it is unclear if any other types of RNAs binding to RNAP exist in bacteria. To identify all RNAs interacting with RNAP and the primary σ factors, we have established and performed native RIP-seq in Bacillus subtilis, Corynebacterium glutamicum, Streptomyces coelicolor, Mycobacterium smegmatis and the pathogenic Mycobacterium tuberculosis. Besides known 6S RNAs in B. subtilis and Ms1 in M. smegmatis, we detected MTS2823, a homologue of Ms1, on RNAP in M. tuberculosis. In C. glutamicum, we discovered novel types of structured RNAs that associate with RNAP. Furthermore, we identified other species-specific RNAs including full-length mRNAs, revealing a previously unknown landscape of RNAs interacting with the bacterial transcription machinery.
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Affiliation(s)
- Viola Vaňková Hausnerová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
- Laboratory of Regulatory RNAs, Faculty of Science, Charles University, Prague128 44, Czech Republic
| | - Mahmoud Shoman
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
- Laboratory of Regulatory RNAs, Faculty of Science, Charles University, Prague128 44, Czech Republic
| | - Dilip Kumar
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
| | - Marek Schwarz
- Laboratory of Bioinformatics, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
| | - Martin Modrák
- Laboratory of Bioinformatics, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
- Department of Bioinformatics, Second Faculty of Medicine, Charles University, Prague150 06, Czech Republic
| | - Jitka Jirát Matějčková
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
- Laboratory of Regulatory RNAs, Faculty of Science, Charles University, Prague128 44, Czech Republic
| | - Eliška Mikesková
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
- Laboratory of Regulatory RNAs, Faculty of Science, Charles University, Prague128 44, Czech Republic
| | - Silvia Neva
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
- Laboratory of Regulatory RNAs, Faculty of Science, Charles University, Prague128 44, Czech Republic
| | - Anna Herrmannová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
| | - Michaela Šiková
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
| | - Petr Halada
- Laboratory of Structural Biology and Cell Signaling, Institute of Microbiology of the Czech Academy of Sciences, Vestec252 50, Czech Republic
| | - Iva Novotná
- Military Health Institute, Military Medical Agency, Prague169 02, Czech Republic
| | - Petr Pajer
- Military Health Institute, Military Medical Agency, Prague169 02, Czech Republic
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, Prague128 00, Czech Republic
| | - Libor Krásný
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
| | - Jarmila Hnilicová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague142 20, Czech Republic
- Laboratory of Regulatory RNAs, Faculty of Science, Charles University, Prague128 44, Czech Republic
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7
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Du X, Qin W, Yang C, Dai L, San M, Xia Y, Zhou S, Wang M, Wu S, Zhang S, Zhou H, Li F, He F, Tang J, Chen JY, Zhou Y, Xiao R. RBM22 regulates RNA polymerase II 5' pausing, elongation rate, and termination by coordinating 7SK-P-TEFb complex and SPT5. Genome Biol 2024; 25:102. [PMID: 38641822 PMCID: PMC11027413 DOI: 10.1186/s13059-024-03242-6] [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: 11/01/2023] [Accepted: 04/09/2024] [Indexed: 04/21/2024] Open
Abstract
BACKGROUND Splicing factors are vital for the regulation of RNA splicing, but some have also been implicated in regulating transcription. The underlying molecular mechanisms of their involvement in transcriptional processes remain poorly understood. RESULTS Here, we describe a direct role of splicing factor RBM22 in coordinating multiple steps of RNA Polymerase II (RNAPII) transcription in human cells. The RBM22 protein widely occupies the RNAPII-transcribed gene locus in the nucleus. Loss of RBM22 promotes RNAPII pause release, reduces elongation velocity, and provokes transcriptional readthrough genome-wide, coupled with production of transcripts containing sequences from downstream of the gene. RBM22 preferentially binds to the hyperphosphorylated, transcriptionally engaged RNAPII and coordinates its dynamics by regulating the homeostasis of the 7SK-P-TEFb complex and the association between RNAPII and SPT5 at the chromatin level. CONCLUSIONS Our results uncover the multifaceted role of RBM22 in orchestrating the transcriptional program of RNAPII and provide evidence implicating a splicing factor in both RNAPII elongation kinetics and termination control.
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Affiliation(s)
- Xian Du
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Wenying Qin
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Chunyu Yang
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Lin Dai
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Mingkui San
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Yingdan Xia
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Siyu Zhou
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Mengyang Wang
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Shuang Wu
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Shaorui Zhang
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Huiting Zhou
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Fangshu Li
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Fang He
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Jingfeng Tang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, School of Life and Health Sciences, Hubei University of Technology, Wuhan, China
| | - Jia-Yu Chen
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing, China
| | - Yu Zhou
- TaiKang Center for Life and Medical Sciences, College of Life Sciences, State Key Laboratory of Virology, Wuhan University, Wuhan, China
| | - Rui Xiao
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China.
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China.
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8
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Mbonye U, Karn J. The cell biology of HIV-1 latency and rebound. Retrovirology 2024; 21:6. [PMID: 38580979 PMCID: PMC10996279 DOI: 10.1186/s12977-024-00639-w] [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] [Indexed: 04/07/2024] Open
Abstract
Transcriptionally latent forms of replication-competent proviruses, present primarily in a small subset of memory CD4+ T cells, pose the primary barrier to a cure for HIV-1 infection because they are the source of the viral rebound that almost inevitably follows the interruption of antiretroviral therapy. Over the last 30 years, many of the factors essential for initiating HIV-1 transcription have been identified in studies performed using transformed cell lines, such as the Jurkat T-cell model. However, as highlighted in this review, several poorly understood mechanisms still need to be elucidated, including the molecular basis for promoter-proximal pausing of the transcribing complex and the detailed mechanism of the delivery of P-TEFb from 7SK snRNP. Furthermore, the central paradox of HIV-1 transcription remains unsolved: how are the initial rounds of transcription achieved in the absence of Tat? A critical limitation of the transformed cell models is that they do not recapitulate the transitions between active effector cells and quiescent memory T cells. Therefore, investigation of the molecular mechanisms of HIV-1 latency reversal and LRA efficacy in a proper physiological context requires the utilization of primary cell models. Recent mechanistic studies of HIV-1 transcription using latently infected cells recovered from donors and ex vivo cellular models of viral latency have demonstrated that the primary blocks to HIV-1 transcription in memory CD4+ T cells are restrictive epigenetic features at the proviral promoter, the cytoplasmic sequestration of key transcription initiation factors such as NFAT and NF-κB, and the vanishingly low expression of the cellular transcription elongation factor P-TEFb. One of the foremost schemes to eliminate the residual reservoir is to deliberately reactivate latent HIV-1 proviruses to enable clearance of persisting latently infected cells-the "Shock and Kill" strategy. For "Shock and Kill" to become efficient, effective, non-toxic latency-reversing agents (LRAs) must be discovered. Since multiple restrictions limit viral reactivation in primary cells, understanding the T-cell signaling mechanisms that are essential for stimulating P-TEFb biogenesis, initiation factor activation, and reversing the proviral epigenetic restrictions have become a prerequisite for the development of more effective LRAs.
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Affiliation(s)
- Uri Mbonye
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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9
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Kuzmina A, Sadhu L, Hasanuzzaman M, Fujinaga K, Schwartz JC, Fackler OT, Taube R. Direct and indirect effects of CYTOR lncRNA regulate HIV gene expression. PLoS Pathog 2024; 20:e1012172. [PMID: 38662769 PMCID: PMC11075828 DOI: 10.1371/journal.ppat.1012172] [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: 09/17/2023] [Revised: 05/07/2024] [Accepted: 04/05/2024] [Indexed: 05/08/2024] Open
Abstract
The implementation of antiretroviral therapy (ART) has effectively restricted the transmission of Human Immunodeficiency Virus (HIV) and improved overall clinical outcomes. However, a complete cure for HIV remains out of reach, as the virus persists in a stable pool of infected cell reservoir that is resistant to therapy and thus a main barrier towards complete elimination of viral infection. While the mechanisms by which host proteins govern viral gene expression and latency are well-studied, the emerging regulatory functions of non-coding RNAs (ncRNA) in the context of T cell activation, HIV gene expression and viral latency have not yet been thoroughly explored. Here, we report the identification of the Cytoskeleton Regulator (CYTOR) long non-coding RNA (lncRNA) as an activator of HIV gene expression that is upregulated following T cell stimulation. Functional studies show that CYTOR suppresses viral latency by directly binding to the HIV promoter and associating with the cellular positive transcription elongation factor (P-TEFb) to activate viral gene expression. CYTOR also plays a global role in regulating cellular gene expression, including those involved in controlling actin dynamics. Depletion of CYTOR expression reduces cytoplasmic actin polymerization in response to T cell activation. In addition, treating HIV-infected cells with pharmacological inhibitors of actin polymerization reduces HIV gene expression. We conclude that both direct and indirect effects of CYTOR regulate HIV gene expression.
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Affiliation(s)
- Alona Kuzmina
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel
| | - Lopamudra Sadhu
- Department of Infectious Diseases, Heidelberg University, Medical Faculty Heidelberg, Integrative Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg, Germany
| | - Md Hasanuzzaman
- Department of Infectious Diseases, Heidelberg University, Medical Faculty Heidelberg, Integrative Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg, Germany
| | - Koh Fujinaga
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
| | - Jacob C. Schwartz
- Department of Pharmacology, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - Oliver T. Fackler
- Department of Infectious Diseases, Heidelberg University, Medical Faculty Heidelberg, Integrative Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg. Germany
| | - Ran Taube
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel
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10
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Alpuche-Lazcano SP, Scarborough RJ, Gatignol A. MicroRNAs and long non-coding RNAs during transcriptional regulation and latency of HIV and HTLV. Retrovirology 2024; 21:5. [PMID: 38424561 PMCID: PMC10905857 DOI: 10.1186/s12977-024-00637-y] [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: 10/15/2023] [Accepted: 02/21/2024] [Indexed: 03/02/2024] Open
Abstract
Human immunodeficiency virus (HIV) and human T cell leukemia virus (HTLV) have replicative and latent stages of infection. The status of the viruses is dependent on the cells that harbour them and on different events that change the transcriptional and post-transcriptional events. Non-coding (nc)RNAs are key factors in the regulation of retrovirus replication cycles. Notably, micro (mi)RNAs and long non-coding (lnc)RNAs are important regulators that can induce switches between active transcription-replication and latency of retroviruses and have important impacts on their pathogenesis. Here, we review the functions of miRNAs and lncRNAs in the context of HIV and HTLV. We describe how specific miRNAs and lncRNAs are involved in the regulation of the viruses' transcription, post-transcriptional regulation and latency. We further discuss treatment strategies using ncRNAs for HIV and HTLV long remission, reactivation or possible cure.
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Affiliation(s)
- Sergio P Alpuche-Lazcano
- Virus-Cell Interactions Laboratory, Lady Davis Institute for Medical Research, 3999, Côte Ste Catherine St., Montréal, QC, H3T 1E2, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, H4A 3J1, Canada
- National Research Council Canada, Montréal, QC, H4P 2R2, Canada
| | - Robert J Scarborough
- Virus-Cell Interactions Laboratory, Lady Davis Institute for Medical Research, 3999, Côte Ste Catherine St., Montréal, QC, H3T 1E2, Canada
- Department of Microbiology and Immunology, McGill University, Montréal, QC, H3A 2B4, Canada
| | - Anne Gatignol
- Virus-Cell Interactions Laboratory, Lady Davis Institute for Medical Research, 3999, Côte Ste Catherine St., Montréal, QC, H3T 1E2, Canada.
- Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, H4A 3J1, Canada.
- Department of Medicine, Division of Infectious Diseases, McGill University, Montréal, QC, H4A 3J1, Canada.
- Department of Microbiology and Immunology, McGill University, Montréal, QC, H3A 2B4, Canada.
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11
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Amir N, Taube R. Role of long noncoding RNA in regulating HIV infection-a comprehensive review. mBio 2024; 15:e0192523. [PMID: 38179937 PMCID: PMC10865847 DOI: 10.1128/mbio.01925-23] [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] [Indexed: 01/06/2024] Open
Abstract
A complete cure against human immunodeficiency virus (HIV) infection remains out of reach, as the virus persists in stable cell reservoirs that are resistant to antiretroviral therapy. The key to eliminating these reservoirs lies in deciphering the processes that govern viral gene expression and latency. However, while we comprehensively understand how host proteins influence HIV gene expression and viral latency, the emerging role of long noncoding RNAs (lncRNAs) in the context of T cell activation, HIV gene expression, and viral latency remain unexplored. This review dives into the evolving significance of lncRNAs and their impact on HIV gene expression and viral latency. We provide an overview of the current knowledge regarding how lncRNAs regulate HIV gene expression, categorizing them as either activators or inhibitors of viral gene expression and infectivity. Furthermore, we offer insights into the potential therapeutic applications of lncRNAs in combatting HIV. A deeper understanding of how lncRNAs modulate HIV gene transcription holds promise for developing novel RNA-based therapies to complement existing treatment strategies to eradicate HIV reservoirs.
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Affiliation(s)
- Noa Amir
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Negev, Israel
| | - Ran Taube
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Negev, Israel
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12
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Hardtke HA, Zhang YJ. Collaborators or competitors: the communication between RNA polymerase II and the nucleosome during eukaryotic transcription. Crit Rev Biochem Mol Biol 2024; 59:1-19. [PMID: 38288999 PMCID: PMC11209794 DOI: 10.1080/10409238.2024.2306365] [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: 11/26/2023] [Accepted: 01/12/2024] [Indexed: 04/22/2024]
Abstract
Decades of scientific research have been devoted to unraveling the intricacies of eukaryotic transcription since the groundbreaking discovery of eukaryotic RNA polymerases in the late 1960s. RNA polymerase II, the polymerase responsible for mRNA synthesis, has always attracted the most attention. Despite its structural resemblance to its bacterial counterpart, eukaryotic RNA polymerase II faces a unique challenge in progressing transcription due to the presence of nucleosomes that package DNA in the nuclei. In this review, we delve into the impact of RNA polymerase II and histone signaling on the progression of eukaryotic transcription. We explore the pivotal points of interactions that bridge the RNA polymerase II and histone signaling systems. Finally, we present an analysis of recent cryo-electron microscopy structures, which captured RNA polymerase II-nucleosome complexes at different stages of the transcription cycle. The combination of the signaling crosstalk and the direct visualization of RNA polymerase II-nucleosome complexes provides a deeper understanding of the communication between these two major players in eukaryotic transcription.
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Affiliation(s)
- Haley A. Hardtke
- Department of Molecular Biosciences, University of Texas, Austin
| | - Y. Jessie Zhang
- Department of Molecular Biosciences, University of Texas, Austin
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13
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Camara MB, Lange B, Yesselman JD, Eichhorn C. Visualizing a two-state conformational ensemble in stem-loop 3 of the transcriptional regulator 7SK RNA. Nucleic Acids Res 2024; 52:940-952. [PMID: 38084902 PMCID: PMC10810284 DOI: 10.1093/nar/gkad1159] [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: 08/23/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 12/26/2023] Open
Abstract
Structural plasticity is integral to RNA function; however, there are currently few methods to quantitatively resolve RNAs that have multiple structural states. NMR spectroscopy is a powerful approach for resolving conformational ensembles but is size-limited. Chemical probing is well-suited for large RNAs but provides limited structural and kinetics information. Here, we integrate the two approaches to visualize a two-state conformational ensemble for the central stem-loop 3 (SL3) of 7SK RNA, a critical element for 7SK RNA function in transcription regulation. We find that the SL3 distal end exchanges between two equally populated yet structurally distinct states in both isolated SL3 constructs and full-length 7SK RNA. We rationally designed constructs that lock SL3 into a single state and demonstrate that both chemical probing and NMR data fit to a linear combination of the two states. Comparison of vertebrate 7SK RNA sequences shows either or both states are highly conserved. These results provide new insights into 7SK RNA structural dynamics and demonstrate the utility of integrating chemical probing with NMR spectroscopy to gain quantitative insights into RNA conformational ensembles.
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Affiliation(s)
- Momodou B Camara
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
| | - Bret Lange
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
| | - Joseph D Yesselman
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE, USA
| | - Catherine D Eichhorn
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE, USA
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14
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Che Z, Liu X, Dai Q, Fang K, Guo C, Yue J, Fang H, Xie P, Luo Z, Lin C. Distinct roles of two SEC scaffold proteins, AFF1 and AFF4, in regulating RNA polymerase II transcription elongation. J Mol Cell Biol 2024; 15:mjad049. [PMID: 37528066 PMCID: PMC11113081 DOI: 10.1093/jmcb/mjad049] [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: 04/04/2023] [Revised: 07/25/2023] [Accepted: 07/31/2023] [Indexed: 08/03/2023] Open
Abstract
The super elongation complex (SEC) containing positive transcription elongation factor b plays a critical role in regulating transcription elongation. AFF1 and AFF4, two members of the AF4/FMR2 family, act as central scaffold proteins of SEC and are associated with various human diseases. However, their precise roles in transcriptional control remain unclear. Here, we investigate differences in the genomic distribution patterns of AFF1 and AFF4 around transcription start sites (TSSs). AFF1 mainly binds upstream of the TSS, while AFF4 is enriched downstream of the TSS. Notably, disruption of AFF4 results in slow elongation and early termination in a subset of AFF4-bound active genes, whereas AFF1 deletion leads to fast elongation and transcriptional readthrough in the same subset of genes. Additionally, AFF1 knockdown increases AFF4 levels at chromatin, and vice versa. In summary, these findings demonstrate that AFF1 and AFF4 function antagonistically to regulate RNA polymerase II transcription.
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Affiliation(s)
- Zhuanzhuan Che
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Xiaoxu Liu
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Qian Dai
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Ke Fang
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Chenghao Guo
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Junjie Yue
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Haitong Fang
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Peng Xie
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Zhuojuan Luo
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Chengqi Lin
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
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15
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Palumbo RJ, Yang Y, Feigon J, Hanes SD. Catalytic activity of the Bin3/MePCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. Genetics 2024; 226:iyad203. [PMID: 37982586 PMCID: PMC10763541 DOI: 10.1093/genetics/iyad203] [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: 05/31/2023] [Revised: 10/27/2023] [Accepted: 11/13/2023] [Indexed: 11/21/2023] Open
Abstract
Methylphosphate Capping Enzyme (MePCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MePCE in vitro, little is known about its functions in vivo, or what roles-if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MePCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MePCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MePCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Yuan Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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16
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Wadhwa N, Kapoor S, Kapoor M. Arabidopsis T-DNA mutants affected in TRDMT1/DNMT2 show differential protein synthesis and compromised stress tolerance. FEBS J 2024; 291:92-113. [PMID: 37584564 DOI: 10.1111/febs.16935] [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: 01/21/2023] [Revised: 07/18/2023] [Accepted: 08/14/2023] [Indexed: 08/17/2023]
Abstract
TRDMT1/DNMT2 belongs to the conserved family of nucleic acid methyltransferases. Unlike the animal systems, studies on TRDMT1/DNMT2 in land plants have been limited. We show that TRDMT1/DNMT2 is strongly conserved in the green lineage. Studies in mosses have previously shown that TRDMT1/DNMT2 plays a crucial role in modulating molecular networks involved in stress perception and signalling and in transcription/stability of specific tRNAs under stress. To gain deeper insight into its biological roles in a flowering plant, we examined more closely the previously reported Arabidopsis SALK_136635C line deficient in TRDMT1/DNMT2 function [Goll MG et al. (2006) Science 311, 395-398]. RNAs derived from Arabidopsis Dnmt2-deficient plants lacked m5 C38 in tRNAAsp . In this study, by transient expression assays we show that Arabidopsis TRDMT1/DNMT2 is distributed in the nucleus, cytoplasm and RNA-processing bodies, suggesting a role for TRDMT1/DNMT2 in RNA metabolic processes possibly by shuttling between cellular compartments. Bright-field and high-resolution SEM and qPCR analysis reveal roles of TRDMT1/DNMT2 in proper growth and developmental progression. Quantitative proteome analysis by LC-MS/MS coupled with qPCR shows AtTRDMT1/AtDNMT2 function to be crucial for protein synthesis and cellular homeostasis via housekeeping roles and proteins with poly-Asp stretches and RNA pol II activity on selected genes are affected in attrdmt1/atdnmt2. This shift in metabolic pathways primes the mutant plants to become increasingly sensitive to oxidative and osmotic stress. Taken together, our study sheds light on the mechanistic role of TRDMT1/DNMT2 in a flowering plant.
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Affiliation(s)
- Nikita Wadhwa
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Sanjay Kapoor
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
- Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Meenu Kapoor
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
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17
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Liao KC, Xie X, Sundstrom AKB, Lim XN, Tan KK, Zhang Y, Zou J, Bifani AM, Poh HX, Chen JJ, Ng WC, Lim SY, Ooi EE, Sessions OM, Tay Y, Shi PY, Huber RG, Wan Y. Dengue and Zika RNA-RNA interactomes reveal pro- and anti-viral RNA in human cells. Genome Biol 2023; 24:279. [PMID: 38053173 PMCID: PMC10696742 DOI: 10.1186/s13059-023-03110-9] [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: 04/18/2023] [Accepted: 11/15/2023] [Indexed: 12/07/2023] Open
Abstract
BACKGROUND Identifying host factors is key to understanding RNA virus pathogenicity. Besides proteins, RNAs can interact with virus genomes to impact replication. RESULTS Here, we use proximity ligation sequencing to identify virus-host RNA interactions for four strains of Zika virus (ZIKV) and one strain of dengue virus (DENV-1) in human cells. We find hundreds of coding and non-coding RNAs that bind to DENV and ZIKV viruses. Host RNAs tend to bind to single-stranded regions along the virus genomes according to hybridization energetics. Compared to SARS-CoV-2 interactors, ZIKV-interacting host RNAs tend to be downregulated upon virus infection. Knockdown of several short non-coding RNAs, including miR19a-3p, and 7SK RNA results in a decrease in viral replication, suggesting that they act as virus-permissive factors. In addition, the 3'UTR of DYNLT1 mRNA acts as a virus-restrictive factor by binding to the conserved dumbbell region on DENV and ZIKV 3'UTR to decrease virus replication. We also identify a conserved set of host RNAs that interacts with DENV, ZIKV, and SARS-CoV-2, suggesting that these RNAs are broadly important for RNA virus infection. CONCLUSIONS This study demonstrates that host RNAs can impact virus replication in permissive and restrictive ways, expanding our understanding of host factors and RNA-based gene regulation during viral pathogenesis.
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Affiliation(s)
- Kuo-Chieh Liao
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Xuping Xie
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Anna Karin Beatrice Sundstrom
- Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Xin Ni Lim
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Kiat Kee Tan
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Yu Zhang
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Jing Zou
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Amanda Makha Bifani
- Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Hui Xian Poh
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Jia Jia Chen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Wy Ching Ng
- Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Su Ying Lim
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Eng Eong Ooi
- Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, 8 College Road, Singapore, 169857, Singapore
| | - October M Sessions
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, 117549, Singapore
- Department of Pharmacy, National University of Singapore, Singapore, 117559, Singapore
| | - Yvonne Tay
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
| | - Roland G Huber
- Biomolecular Function Discovery, Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Matrix #07-01, Singapore, 138671, Singapore.
| | - Yue Wan
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, 138672, Singapore.
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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18
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Wang Y, Traugot CM, Bubenik JL, Li T, Sheng P, Hiers NM, Fernandez P, Li L, Bian J, Swanson MS, Xie M. N 6-methyladenosine in 7SK small nuclear RNA underlies RNA polymerase II transcription regulation. Mol Cell 2023; 83:3818-3834.e7. [PMID: 37820733 PMCID: PMC10873123 DOI: 10.1016/j.molcel.2023.09.020] [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: 02/27/2023] [Revised: 08/07/2023] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
N6-methyladenosine (m6A) modifications play crucial roles in RNA metabolism. How m6A regulates RNA polymerase II (RNA Pol II) transcription remains unclear. We find that 7SK small nuclear RNA (snRNA), a regulator of RNA Pol II promoter-proximal pausing, is highly m6A-modified in non-small cell lung cancer (NSCLC) cells. In A549 cells, we identified eight m6A sites on 7SK and discovered methyltransferase-like 3 (METTL3) and alkB homolog 5 (ALKBH5) as the responsible writer and eraser. When the m6A-7SK is specifically erased by a dCasRx-ALKBH5 fusion protein, A549 cell growth is attenuated due to reduction of RNA Pol II transcription. Mechanistically, removal of m6A leads to 7SK structural rearrangements that facilitate sequestration of the positive transcription elongation factor b (P-TEFb) complex, which results in reduction of serine 2 phosphorylation (Ser2P) in the RNA Pol II C-terminal domain and accumulation of RNA Pol II in the promoter-proximal region. Taken together, we uncover that m6A modifications of a non-coding RNA regulate RNA Pol II transcription and NSCLC tumorigenesis.
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Affiliation(s)
- Yuzhi Wang
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Conner M Traugot
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Jodi L Bubenik
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; UF Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Tianqi Li
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Peike Sheng
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Nicholas M Hiers
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Paul Fernandez
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Lu Li
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Jiang Bian
- UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA; Department of Health Outcomes & Biomedical Informatics, University of Florida, Gainesville, FL 32610, USA
| | - Maurice S Swanson
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; UF Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Mingyi Xie
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA; UF Genetics Institute, University of Florida, Gainesville, FL 32610, USA.
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19
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Behrens RT, Rajashekar JK, Bruce JW, Evans EL, Hansen AM, Salazar-Quiroz N, Simons LM, Ahlquist P, Hultquist JF, Kumar P, Sherer NM. Exploiting a rodent cell block for intrinsic resistance to HIV-1 gene expression in human T cells. mBio 2023; 14:e0042023. [PMID: 37676006 PMCID: PMC10653828 DOI: 10.1128/mbio.00420-23] [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: 04/06/2023] [Accepted: 07/13/2023] [Indexed: 09/08/2023] Open
Abstract
IMPORTANCE Unlike humans, mice are unable to support HIV-1 infection. This is due, in part, to a constellation of defined minor, species-specific differences in conserved host proteins needed for viral gene expression. Here, we used precision CRISPR/Cas9 gene editing to engineer a "mousified" version of one such host protein, cyclin T1 (CCNT1), in human T cells. CCNT1 is essential for efficient HIV-1 transcription, making it an intriguing target for gene-based inactivation of virus replication. We show that isogenic cell lines engineered to encode CCNT1 bearing a single mouse-informed amino acid change (tyrosine in place of cysteine at position 261) exhibit potent, durable, and broad-spectrum resistance to HIV-1 and other pathogenic lentiviruses, and with no discernible impact on host cell biology. These results provide proof of concept for targeting CCNT1 in the context of one or more functional HIV-1 cure strategies.
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Affiliation(s)
- Ryan T. Behrens
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jyothi Krishnaswamy Rajashekar
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut, USA
| | - James W. Bruce
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Edward L. Evans
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Amelia M. Hansen
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Natalia Salazar-Quiroz
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Lacy M. Simons
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Paul Ahlquist
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Judd F. Hultquist
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Priti Kumar
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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20
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Zhou S, Van Bortle K. The Pol III transcriptome: Basic features, recurrent patterns, and emerging roles in cancer. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1782. [PMID: 36754845 PMCID: PMC10498592 DOI: 10.1002/wrna.1782] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 02/10/2023]
Abstract
The RNA polymerase III (Pol III) transcriptome is universally comprised of short, highly structured noncoding RNA (ncRNA). Through RNA-protein interactions, the Pol III transcriptome actuates functional activities ranging from nuclear gene regulation (7SK), splicing (U6, U6atac), and RNA maturation and stability (RMRP, RPPH1, Y RNA), to cytoplasmic protein targeting (7SL) and translation (tRNA, 5S rRNA). In higher eukaryotes, the Pol III transcriptome has expanded to include additional, recently evolved ncRNA species that effectively broaden the footprint of Pol III transcription to additional cellular activities. Newly evolved ncRNAs function as riboregulators of autophagy (vault), immune signaling cascades (nc886), and translation (Alu, BC200, snaR). Notably, upregulation of Pol III transcription is frequently observed in cancer, and multiple ncRNA species are linked to both cancer progression and poor survival outcomes among cancer patients. In this review, we outline the basic features and functions of the Pol III transcriptome, and the evidence for dysregulation and dysfunction for each ncRNA in cancer. When taken together, recurrent patterns emerge, ranging from shared functional motifs that include molecular scaffolding and protein sequestration, overlapping protein interactions, and immunostimulatory activities, to the biogenesis of analogous small RNA fragments and noncanonical miRNAs, augmenting the function of the Pol III transcriptome and further broadening its role in cancer. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Processing of Small RNAs RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Sihang Zhou
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Kevin Van Bortle
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
- Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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21
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Wadhwa N, Singh D, Yadav R, Kapoor S, Kapoor M. Role of TRDMT1/DNMT2 in stress adaptation and its influence on transcriptome and proteome dynamics under osmotic stress in Physcomitrium patens. PHYSIOLOGIA PLANTARUM 2023; 175:e14014. [PMID: 37882266 DOI: 10.1111/ppl.14014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/07/2023] [Accepted: 08/21/2023] [Indexed: 10/27/2023]
Abstract
Early land plants such as the moss Physcomitrium patens lack several morphological traits that offer protection to tracheophytes from environmental stresses. These plants instead have evolved several physiological and biochemical mechanisms that facilitate them to adapt to terrestrial stresses such as drought. We have previously shown that loss-of-function mutants of tRNA (cytosine(38)-C(5))-methyltransferase TRDMT1/DNMT2 in P. patens are highly sensitive to oxidative and osmotic stress. To gain insight into the role of PpTRDMT1/PpDNMT2 in modulating genetic networks under osmotic stress, genome-wide transcriptome and proteome studies were undertaken in wild-type and ppdnmt2 plants. Transcriptome analysis revealed 375 genes to be differentially expressed in the ppdnmt2 under stress compared to the WT. Most of these genes are affiliated with carbohydrate metabolic pathways, photosynthesis, cell wall biogenesis, pathways related to isotropic and polarised cell growth and transcription factors among others. Histochemical staining showed elevated levels of reactive oxygen species in ppdnmt2 while transmission electron microscopy revealed no distinct defects in the ultrastructure of chloroplasts. Immunoprecipitation using PpDNMT2-specific antibody coupled with mass spectrometry revealed core proteins of the glycolytic pathway, antioxidant enzymes, proteins of amino acid biosynthetic pathways and photosynthesis-related proteins among others to co-purify with PpTRDMT1/PpDNMT2 under osmotic stress. Yeast two-hybrid assays, protein deletion and α-galactosidase assays showed the cytosol glycolytic protein glyceraldehyde 3-phosphate dehydrogenase to bind to the catalytic motifs in PpTRDMT1/PpDNMT2. Results presented in this study allow us to better understand genetic networks linking enzymes of energy metabolism, epigenetic processes and RNA pol II-mediated transcription during osmotic stress tolerance in P. patens.
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Affiliation(s)
- Nikita Wadhwa
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
| | - Darshika Singh
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
| | - Radha Yadav
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
| | - Sanjay Kapoor
- Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, Delhi, India
| | - Meenu Kapoor
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
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22
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Ma T, Xiong ES, Lardelli RM, Lykke-Andersen J. The 3' exonuclease TOE1 selectively processes snRNAs through recognition of Sm complex assembly and 5' cap trimethylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.15.553431. [PMID: 37645788 PMCID: PMC10462049 DOI: 10.1101/2023.08.15.553431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Competing exonucleases that promote 3' end maturation or degradation direct quality control of small non-coding RNAs, but how these enzymes distinguish normal from aberrant RNAs is poorly understood. The Pontocerebellar Hypoplasia 7 (PCH7)-associated 3' exonuclease TOE1 promotes maturation of canonical small nuclear RNAs (snRNAs). Here, we demonstrate that TOE1 achieves specificity towards canonical snRNAs by recognizing Sm complex assembly and cap trimethylation, two features that distinguish snRNAs undergoing correct biogenesis from other small non-coding RNAs. Indeed, disruption of Sm complex assembly via snRNA mutations or protein depletions obstructs snRNA processing by TOE1, and in vitro snRNA processing by TOE1 is stimulated by a trimethylated cap. An unstable snRNA variant that normally fails to undergo maturation becomes fully processed by TOE1 when its degenerate Sm binding motif is converted into a canonical one. Our findings uncover the molecular basis for how TOE1 distinguishes snRNAs from other small non-coding RNAs and explain how TOE1 promotes maturation specifically of canonical snRNAs undergoing proper processing.
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Affiliation(s)
- Tiantai Ma
- Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Erica S Xiong
- Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Rea M Lardelli
- Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Jens Lykke-Andersen
- Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
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23
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Camara MB, Lange B, Yesselman JD, Eichhorn CD. Visualizing a two-state conformational ensemble in stem-loop 3 of the transcriptional regulator 7SK RNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.09.552709. [PMID: 37609139 PMCID: PMC10441402 DOI: 10.1101/2023.08.09.552709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Structural plasticity is integral to RNA function; however, there are currently few methods to quantitatively resolve RNAs that have multiple structural states. NMR spectroscopy is a powerful approach for resolving conformational ensembles but is size-limited. Chemical probing is well-suited for large RNAs but provides limited structural and no kinetics information. Here, we integrate the two approaches to visualize a two-state conformational ensemble for the central stem-loop 3 (SL3) of 7SK RNA, a critical element for 7SK RNA function in transcription regulation. We find that the SL3 distal end exchanges between two equally populated yet structurally distinct states in both isolated SL3 constructs and full-length 7SK RNA. We rationally designed constructs that lock SL3 into a single state and demonstrate that both chemical probing and NMR data fit to a linear combination of the two states. Comparison of vertebrate 7SK RNA sequences shows conservation of both states, suggesting functional importance. These results provide new insights into 7SK RNA structural dynamics and demonstrate the utility of integrating chemical probing with NMR spectroscopy to gain quantitative insights into RNA conformational ensembles.
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Affiliation(s)
- Momodou B. Camara
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
| | - Bret Lange
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
| | - Joseph D. Yesselman
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication
| | - Catherine D. Eichhorn
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication
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24
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Pal S, Biswas D. Promoter-proximal regulation of gene transcription: Key factors involved and emerging role of general transcription factors in assisting productive elongation. Gene 2023:147571. [PMID: 37331491 DOI: 10.1016/j.gene.2023.147571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 06/20/2023]
Abstract
The pausing of RNA polymerase II (Pol II) at the promoter-proximal sites is a key rate-limiting step in gene expression. Cells have dedicated a specific set of proteins that sequentially establish pause and then release the Pol II from promoter-proximal sites. A well-controlled pausing and subsequent release of Pol II is crucial for thefine tuning of expression of genes including signal-responsive and developmentally-regulated ones. The release of paused Pol II broadly involves its transition from initiation to elongation. In this review article, we will discuss the phenomenon of Pol II pausing, the underlying mechanism, and also the role of different known factors, with an emphasis on general transcription factors, involved in this overall regulation. We will further discuss some recent findings suggesting a possible role (underexplored) of initiation factors in assisting the transition of transcriptionally-engaged paused Pol II into productive elongation.
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Affiliation(s)
- Sujay Pal
- Laboratory of Transcription Biology, Molecular Genetics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata - 32, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Debabrata Biswas
- Laboratory of Transcription Biology, Molecular Genetics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata - 32, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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25
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Wooten M, Takushi B, Ahmad K, Henikoff S. Aclarubicin stimulates RNA polymerase II elongation at closely spaced divergent promoters. SCIENCE ADVANCES 2023; 9:eadg3257. [PMID: 37315134 DOI: 10.1126/sciadv.adg3257] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 05/08/2023] [Indexed: 06/16/2023]
Abstract
Anthracyclines are a class of widely prescribed anticancer drugs that disrupt chromatin by intercalating into DNA and enhancing nucleosome turnover. To understand the molecular consequences of anthracycline-mediated chromatin disruption, we used Cleavage Under Targets and Tagmentation (CUT&Tag) to profile RNA polymerase II during anthracycline treatment in Drosophila cells. We observed that treatment with the anthracycline aclarubicin leads to elevated levels of RNA polymerase II and changes in chromatin accessibility. We found that promoter proximity and orientation affect chromatin changes during aclarubicin treatment, as closely spaced divergent promoter pairs show greater chromatin changes when compared to codirectionally oriented tandem promoters. We also found that aclarubicin treatment changes the distribution of noncanonical DNA G-quadruplex structures both at promoters and at G-rich pericentromeric repeats. Our work suggests that the cancer-killing activity of aclarubicin is driven by the disruption of nucleosomes and RNA polymerase II.
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Affiliation(s)
| | | | - Kami Ahmad
- Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Steven Henikoff
- Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
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26
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Palumbo RJ, Hanes SD. Catalytic activity of the Bin3/MEPCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.01.543302. [PMID: 37333392 PMCID: PMC10274667 DOI: 10.1101/2023.06.01.543302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Methylphosphate Capping Enzyme (MEPCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MEPCE in vitro, little is known about its functions in vivo, or what roles- if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MEPCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MEPCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MEPCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
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27
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Liu R. Brd4-dependent CDK9 expression induction upon sustained pharmacological inhibition of P-TEFb kinase activity. Biochem Biophys Res Commun 2023; 671:75-79. [PMID: 37295357 DOI: 10.1016/j.bbrc.2023.05.114] [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: 05/18/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023]
Abstract
CDK9 is the kinase subunit of P-TEFb (positive transcription elongation factor b), which is crucial for effective transcriptional elongation. The activity of P-TEFb is well maintained, mainly through dynamic association with several larger protein complexes. Here, we show that CDK9 expression is induced upon inhibition of P-TEFb activity, a process dependent on Brd4 as later revealed. Brd4 inhibition synergizes with CDK9 inhibitor to suppress P-TEFb activity and tumor cell growth. Our study suggests that combined inhibition of Brd4 and CDK9 can be evaluated as a potential therapeutic strategy.
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Affiliation(s)
- Rongdiao Liu
- Key Laboratory of Diagnosis and Treatment of Severe Hepato-Pancreatic Diseases of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
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28
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Perez-Pepe M, Desotell AW, Li H, Li W, Han B, Lin Q, Klein DE, Liu Y, Goodarzi H, Alarcón CR. 7SK methylation by METTL3 promotes transcriptional activity. SCIENCE ADVANCES 2023; 9:eade7500. [PMID: 37163588 PMCID: PMC10171809 DOI: 10.1126/sciadv.ade7500] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 04/07/2023] [Indexed: 05/12/2023]
Abstract
A fundamental feature of cell signaling is the conversion of extracellular signals into adaptive transcriptional responses. The role of RNA modifications in this process is poorly understood. The small nuclear RNA 7SK prevents transcriptional elongation by sequestering the cyclin dependent kinase 9/cyclin T1 (CDK9/CCNT1) positive transcription elongation factor (P-TEFb) complex. We found that epidermal growth factor signaling induces phosphorylation of the enzyme methyltransferase 3 (METTL3), leading to METTL3-mediated methylation of 7SK. 7SK methylation enhanced its binding to heterogeneous nuclear ribonucleoproteins, causing the release of the HEXIM1 P-TEFb complex subunit1 (HEXIM1)/P-TEFb complex and inducing transcriptional elongation. Our findings establish the mechanism underlying 7SK activation and uncover a previously unknown function for the m6A modification in converting growth factor signaling events into a regulatory transcriptional response via an RNA methylation-dependent switch.
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Affiliation(s)
- Marcelo Perez-Pepe
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Anthony W. Desotell
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Hengyi Li
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Wenxue Li
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Bing Han
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Qishan Lin
- RNA Epitranscriptomics and Proteomics Resource, University at Albany, Albany, NY 12222, USA
| | - Daryl E. Klein
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Yansheng Liu
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Hani Goodarzi
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Claudio R. Alarcón
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
- Yale Cancer Biology Institute, Yale University, West Haven, CT 06516, USA
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29
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Camara MB, Sobeh AM, Eichhorn CD. Progress in 7SK ribonucleoprotein structural biology. Front Mol Biosci 2023; 10:1154622. [PMID: 37051324 PMCID: PMC10083321 DOI: 10.3389/fmolb.2023.1154622] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/16/2023] [Indexed: 03/29/2023] Open
Abstract
The 7SK ribonucleoprotein (RNP) is a dynamic and multifunctional regulator of RNA Polymerase II (RNAPII) transcription in metazoa. Comprised of the non-coding 7SK RNA, core proteins, and numerous accessory proteins, the most well-known 7SK RNP function is the sequestration and inactivation of the positive transcription elongation factor b (P-TEFb). More recently, 7SK RNP has been shown to regulate RNAPII transcription through P-TEFb-independent pathways. Due to its fundamental role in cellular function, dysregulation has been linked with human diseases including cancers, heart disease, developmental disorders, and viral infection. Significant advances in 7SK RNP structural biology have improved our understanding of 7SK RNP assembly and function. Here, we review progress in understanding the structural basis of 7SK RNA folding, biogenesis, and RNP assembly.
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Affiliation(s)
- Momodou B. Camara
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
| | - Amr M. Sobeh
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
| | - Catherine D. Eichhorn
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
- Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE, United States
- *Correspondence: Catherine D. Eichhorn,
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30
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Kulkarni V, Jayakumar S, Mohan M, Kulkarni S. Aid or Antagonize: Nuclear Long Noncoding RNAs Regulate Host Responses and Outcomes of Viral Infections. Cells 2023; 12:987. [PMID: 37048060 PMCID: PMC10093752 DOI: 10.3390/cells12070987] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 03/12/2023] [Accepted: 03/15/2023] [Indexed: 04/14/2023] Open
Abstract
Long noncoding RNAs (lncRNAs) are transcripts measuring >200 bp in length and devoid of protein-coding potential. LncRNAs exceed the number of protein-coding mRNAs and regulate cellular, developmental, and immune pathways through diverse molecular mechanisms. In recent years, lncRNAs have emerged as epigenetic regulators with prominent roles in health and disease. Many lncRNAs, either host or virus-encoded, have been implicated in critical cellular defense processes, such as cytokine and antiviral gene expression, the regulation of cell signaling pathways, and the activation of transcription factors. In addition, cellular and viral lncRNAs regulate virus gene expression. Viral infections and associated immune responses alter the expression of host lncRNAs regulating immune responses, host metabolism, and viral replication. The influence of lncRNAs on the pathogenesis and outcomes of viral infections is being widely explored because virus-induced lncRNAs can serve as diagnostic and therapeutic targets. Future studies should focus on thoroughly characterizing lncRNA expressions in virus-infected primary cells, investigating their role in disease prognosis, and developing biologically relevant animal or organoid models to determine their suitability for specific therapeutic targeting. Many cellular and viral lncRNAs localize in the nucleus and epigenetically modulate viral transcription, latency, and host responses to infection. In this review, we provide an overview of the role of nuclear lncRNAs in the pathogenesis and outcomes of viral infections, such as the Influenza A virus, Sendai Virus, Respiratory Syncytial Virus, Hepatitis C virus, Human Immunodeficiency Virus, and Herpes Simplex Virus. We also address significant advances and barriers in characterizing lncRNA function and explore the potential of lncRNAs as therapeutic targets.
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Affiliation(s)
- Viraj Kulkarni
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA;
| | - Sahana Jayakumar
- Host-Pathogen Interaction Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (S.J.); (M.M.)
| | - Mahesh Mohan
- Host-Pathogen Interaction Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (S.J.); (M.M.)
| | - Smita Kulkarni
- Host-Pathogen Interaction Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (S.J.); (M.M.)
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31
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Fujinaga K, Huang F, Peterlin BM. P-TEFb: The master regulator of transcription elongation. Mol Cell 2023; 83:393-403. [PMID: 36599353 PMCID: PMC9898187 DOI: 10.1016/j.molcel.2022.12.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/10/2022] [Accepted: 12/08/2022] [Indexed: 01/05/2023]
Abstract
The positive transcription elongation factor b (P-TEFb) is composed of cyclins T1 or T2 and cyclin-dependent kinase 9 that regulate the elongation phase of transcription by RNA polymerase II. By antagonizing negative elongation factors and phosphorylating the C-terminal domain of RNA polymerase II, P-TEFb facilitates the elongation and co-transcriptional processing of nascent transcripts. This step is critical for the expression of most eukaryotic genes. In growing cells, P-TEFb is regulated negatively by its reversible associations with HEXIM1/2 in the 7SK snRNP and positively by a number of transcription factors, as well as the super elongation complex. In resting cells, P-TEFb falls apart, and cyclin T1 is degraded by the proteasome. This complex regulation of P-TEFb has evolved for the precise temporal and spatial regulation of gene expression in the organism. Its dysregulation contributes to inflammatory and neoplastic conditions.
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Affiliation(s)
- Koh Fujinaga
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA.
| | - Fang Huang
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA
| | - B Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA.
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32
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Sobeh AM, Eichhorn CD. C-terminal determinants for RNA binding motif 7 protein stability and RNA recognition. Biophys Chem 2023; 292:106928. [PMID: 36427363 PMCID: PMC9768861 DOI: 10.1016/j.bpc.2022.106928] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 10/13/2022] [Accepted: 10/30/2022] [Indexed: 11/09/2022]
Abstract
The 7SK ribonucleoprotein (RNP) is a critical regulator of eukaryotic transcription. Recently, RNA binding motif 7 (RBM7) containing an RNA recognition motif (RRM) was reported to associate with 7SK RNA and core 7SK RNP protein components in response to DNA damage. However, little is known about the mode of RBM7-7SK RNA recognition. Here, we found that RRM constructs containing extended C-termini have increased solubility compared to a minimal RRM construct, although these constructs aggregate in a temperature and concentration-dependent manner. Using solution NMR dynamics experiments, we identified additional structural features observed previously in crystal but not in solution structures. To identify potential RBM7-7SK RNA binding sites, we analyzed deposited data from in cellulo crosslinking experiments and found that RBM7 primarily crosslinks to the distal region of 7SK stem-loop 3 (SL3). Electrophoretic mobility shift assays and NMR chemical shift perturbation experiments showed weak binding to 7SK SL3 constructs in vitro. Together, these results provide new insights into RBM7 RRM folding and recognition of 7SK RNA.
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Affiliation(s)
- Amr M Sobeh
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
| | - Catherine D Eichhorn
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA.
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33
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Whelan M, Pelchat M. Role of RNA Polymerase II Promoter-Proximal Pausing in Viral Transcription. Viruses 2022; 14:v14092029. [PMID: 36146833 PMCID: PMC9503719 DOI: 10.3390/v14092029] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/09/2022] [Accepted: 09/11/2022] [Indexed: 11/16/2022] Open
Abstract
The promoter-proximal pause induced by the binding of the DRB sensitivity-inducing factor (DSIF) and the negative elongation factor (NELF) to RNAP II is a key step in the regulation of metazoan gene expression. It helps maintain a permissive chromatin landscape and ensures a quick transcriptional response from stimulus-responsive pathways such as the innate immune response. It is also involved in the biology of several RNA viruses such as the human immunodeficiency virus (HIV), the influenza A virus (IAV) and the hepatitis delta virus (HDV). HIV uses the pause as one of its mechanisms to enter and maintain latency, leading to the creation of viral reservoirs resistant to antiretrovirals. IAV, on the other hand, uses the pause to acquire the capped primers necessary to initiate viral transcription through cap-snatching. Finally, the HDV RNA genome is transcribed directly by RNAP II and requires the small hepatitis delta antigen to displace NELF from the polymerase and overcome the transcriptional block caused by RNAP II promoter-proximal pausing. In this review, we will discuss the RNAP II promoter-proximal pause and the roles it plays in the life cycle of RNA viruses such as HIV, IAV and HDV.
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34
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Ji C, Deng C, Antor K, Bischler T, Schneider C, Fischer U, Sendtner M, Briese M. hnRNP
R negatively regulates transcription by modulating the association of
P‐TEFb
with
7SK
and
BRD4. EMBO Rep 2022; 23:e55432. [PMID: 35856391 PMCID: PMC9442301 DOI: 10.15252/embr.202255432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Changhe Ji
- Institute of Clinical Neurobiology University Hospital Wuerzburg Wuerzburg Germany
| | - Chunchu Deng
- Institute of Clinical Neurobiology University Hospital Wuerzburg Wuerzburg Germany
| | - Katharina Antor
- Institute of Clinical Neurobiology University Hospital Wuerzburg Wuerzburg Germany
| | - Thorsten Bischler
- Core Unit Systems Medicine University of Wuerzburg Wuerzburg Germany
| | - Cornelius Schneider
- Department of Biochemistry, Theodor Boveri Institute University of Wuerzburg Wuerzburg Germany
| | - Utz Fischer
- Department of Biochemistry, Theodor Boveri Institute University of Wuerzburg Wuerzburg Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology University Hospital Wuerzburg Wuerzburg Germany
| | - Michael Briese
- Institute of Clinical Neurobiology University Hospital Wuerzburg Wuerzburg Germany
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35
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Pham VV, Gao M, Meagher JL, Smith JL, D'Souza VM. A structure-based mechanism for displacement of the HEXIM adapter from 7SK small nuclear RNA. Commun Biol 2022; 5:819. [PMID: 35970937 PMCID: PMC9378691 DOI: 10.1038/s42003-022-03734-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 07/19/2022] [Indexed: 11/09/2022] Open
Abstract
Productive transcriptional elongation of many cellular and viral mRNAs requires transcriptional factors to extract pTEFb from the 7SK snRNP by modulating the association between HEXIM and 7SK snRNA. In HIV-1, Tat binds to 7SK by displacing HEXIM. However, without the structure of the 7SK-HEXIM complex, the constraints that must be overcome for displacement remain unknown. Furthermore, while structure details of the TatNL4-3-7SK complex have been elucidated, it is unclear how subtypes with more HEXIM-like Tat sequences accomplish displacement. Here we report the structures of HEXIM, TatG, and TatFin arginine rich motifs in complex with the apical stemloop-1 of 7SK. While most interactions between 7SK with HEXIM and Tat are similar, critical differences exist that guide function. First, the conformational plasticity of 7SK enables the formation of three different base pair configurations at a critical remodeling site, which allows for the modulation required for HEXIM binding and its subsequent displacement by Tat. Furthermore, the specific sequence variations observed in various Tat subtypes all converge on remodeling 7SK at this region. Second, we show that HEXIM primes its own displacement by causing specific local destabilization upon binding - a feature that is then exploited by Tat to bind 7SK more efficiently.
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Affiliation(s)
- Vincent V Pham
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Michael Gao
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jennifer L Meagher
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Janet L Smith
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Victoria M D'Souza
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA.
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Abstract
Enhancers confer precise spatiotemporal patterns of gene expression in response to developmental and environmental stimuli. Over the last decade, the transcription of enhancer RNAs (eRNAs) – nascent RNAs transcribed from active enhancers – has emerged as a key factor regulating enhancer activity. eRNAs are relatively short-lived RNA species that are transcribed at very high rates but also quickly degraded. Nevertheless, eRNAs are deeply intertwined within enhancer regulatory networks and are implicated in a number of transcriptional control mechanisms. Enhancers show changes in function and sequence over evolutionary time, raising questions about the relationship between enhancer sequences and eRNA function. Moreover, the vast majority of single nucleotide polymorphisms associated with human complex diseases map to the non-coding genome, with causal disease variants enriched within enhancers. In this Primer, we survey the diverse roles played by eRNAs in enhancer-dependent gene expression, evaluating different models for eRNA function. We also explore questions surrounding the genetic conservation of enhancers and how this relates to eRNA function and dysfunction. Summary: This Primer evaluates the ideas that underpin developing models for eRNA function, exploring cases in which perturbed eRNA function contributes to disease.
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Affiliation(s)
- Laura J. Harrison
- Molecular and Cellular Biology, School of Biosciences, Sheffield Institute For Nucleic Acids, The University of Sheffield, Firth Court, Western Bank , Sheffield S10 2TN , UK
| | - Daniel Bose
- Molecular and Cellular Biology, School of Biosciences, Sheffield Institute For Nucleic Acids, The University of Sheffield, Firth Court, Western Bank , Sheffield S10 2TN , UK
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Fang Y, Wang Y, Spector BM, Xiao X, Yang C, Li P, Yuan Y, Ding P, Xiao ZX, Zhang P, Qiu T, Zhu X, Price DH, Li Q. Dynamic regulation of P-TEFb by 7SK snRNP is integral to the DNA damage response to regulate chemotherapy sensitivity. iScience 2022; 25:104844. [PMID: 36034227 PMCID: PMC9399290 DOI: 10.1016/j.isci.2022.104844] [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: 11/22/2021] [Revised: 07/15/2022] [Accepted: 07/21/2022] [Indexed: 11/28/2022] Open
Abstract
Testicular germ cell tumors and closely related embryonal stem cells are exquisitely sensitive to cisplatin, a feature thought to be linked to their pluripotent state and p53 status. It remains unclear whether and how cellular state is coordinated with p53 to confer cisplatin sensitivity. Here, we report that positive transcription elongation factor b (P-TEFb) determines cell fate upon DNA damage. We find that cisplatin rapidly activates P-TEFb by releasing it from inhibitory 7SK small nuclear ribonucleoprotein complex. P-TEFb directly phosphorylates pluripotency factor estrogen-related receptor beta (ESRRB), and induces its proteasomal degradation to enhance pro-survival glycolysis. On the other hand, P-TEFb is required for the transcription of a substantial portion of p53 target genes, triggering cell death during prolonged cisplatin treatment. These results reveal previously underappreciated roles of P-TEFb to coordinate the DNA damage response. We discuss the implications for using P-TEFb inhibitors to treat cancer and ameliorate cisplatin-induced ototoxicity. P-TEFb regulates pro-survival and pro-death pathways during DNA damage response P-TEFb promotes ESRRB proteasomal degradation to enhance pro-survival glycolysis P-TEFb induces a substantial portion of p53 target genes to trigger cell death Chemical inhibitors of P-TEFb blocks cisplatin- or UV-induced cell death
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Affiliation(s)
- Yin Fang
- Departments of Pediatrics and Obstetrics & Gynecology, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Center of Growth, Metabolism and Aging, College of Life Sciences, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Yan Wang
- Departments of Pediatrics and Obstetrics & Gynecology, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Center of Growth, Metabolism and Aging, College of Life Sciences, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | | | - Xue Xiao
- Departments of Pediatrics and Obstetrics & Gynecology, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Center of Growth, Metabolism and Aging, College of Life Sciences, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Chao Yang
- Division of Bioinformatics, Sichuan Cunde Therapeutics, Chengdu 610093, China
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu 610500, China
| | - Ping Li
- Departments of Pediatrics and Obstetrics & Gynecology, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Center of Growth, Metabolism and Aging, College of Life Sciences, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Yuan Yuan
- Division of Bioinformatics, Sichuan Cunde Therapeutics, Chengdu 610093, China
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu 610500, China
| | - Ping Ding
- Division of Bioinformatics, Sichuan Cunde Therapeutics, Chengdu 610093, China
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu 610500, China
| | - Zhi-Xiong Xiao
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
| | - Peixuan Zhang
- Departments of Pediatrics and Obstetrics & Gynecology, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Center of Growth, Metabolism and Aging, College of Life Sciences, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Tong Qiu
- Departments of Pediatrics and Obstetrics & Gynecology, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Center of Growth, Metabolism and Aging, College of Life Sciences, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Xiaofeng Zhu
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
- Corresponding author
| | - David H. Price
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
- Corresponding author
| | - Qintong Li
- Departments of Pediatrics and Obstetrics & Gynecology, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Center of Growth, Metabolism and Aging, College of Life Sciences, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
- Corresponding author
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Woudenberg T, Kruyt ND, Quax PHA, Nossent AY. Change of Heart: the Epitranscriptome of Small Non-coding RNAs in Heart Failure. Curr Heart Fail Rep 2022; 19:255-266. [PMID: 35876969 PMCID: PMC9534797 DOI: 10.1007/s11897-022-00561-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/05/2022] [Indexed: 12/25/2022]
Abstract
Purpose of Review Small non-coding RNAs regulate gene expression and are highly implicated in heart failure. Recently, an additional level of post-transcriptional regulation has been identified, referred to as the epitranscriptome, which encompasses the body of post-transcriptional modifications that are placed on RNA molecules. In this review, we summarize the current knowledge on the small non-coding RNA epitranscriptome in heart failure. Recent Findings With the rise of new methods to study RNA modifications, epitranscriptome research has begun to take flight. Over the past 3 years, the number of publications on the epitranscriptome in heart failure has significantly increased, and we expect many more highly relevant publications to come out over the next few years. Summary Currently, at least six modifications on small non-coding RNAs have been investigated in heart failure-relevant studies, namely N6-adenosine, N5-cytosine and N7-guanosine methylation, 2’-O-ribose-methylation, adenosine-to-inosine editing, and isomiRs. Their potential role in heart failure is discussed.
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Affiliation(s)
- Tamar Woudenberg
- Department of Surgery, Leiden University Medical Center, D6-P, PO Box 9600, 2300 RC, Leiden, the Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Nyika D Kruyt
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
| | - Paul H A Quax
- Department of Surgery, Leiden University Medical Center, D6-P, PO Box 9600, 2300 RC, Leiden, the Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - A Yaël Nossent
- Department of Surgery, Leiden University Medical Center, D6-P, PO Box 9600, 2300 RC, Leiden, the Netherlands. .,Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands.
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Guénolé A, Velilla F, Chartier A, Rich A, Carvunis AR, Sardet C, Simonelig M, Sobhian B. RNF219 regulates CCR4-NOT function in mRNA translation and deadenylation. Sci Rep 2022; 12:9288. [PMID: 35660762 PMCID: PMC9166816 DOI: 10.1038/s41598-022-13309-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 05/05/2022] [Indexed: 11/30/2022] Open
Abstract
Post-transcriptional regulatory mechanisms play a role in many biological contexts through the control of mRNA degradation, translation and localization. Here, we show that the RING finger protein RNF219 co-purifies with the CCR4-NOT complex, the major mRNA deadenylase in eukaryotes, which mediates translational repression in both a deadenylase activity-dependent and -independent manner. Strikingly, RNF219 both inhibits the deadenylase activity of CCR4-NOT and enhances its capacity to repress translation of a target mRNA. We propose that the interaction of RNF219 with the CCR4-NOT complex directs the translational repressive activity of CCR4-NOT to a deadenylation-independent mechanism.
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Affiliation(s)
- Aude Guénolé
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), 34298, Montpellier, France.
| | - Fabien Velilla
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), 34298, Montpellier, France
| | - Aymeric Chartier
- Institut de Génétique Humaine, CNRS, Université de Montpellier, 34396, Montpellier, France
| | - April Rich
- Department of Computational and Systems Biology, Pittsburgh Center for Evolutionary Biology and Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Anne-Ruxandra Carvunis
- Department of Computational and Systems Biology, Pittsburgh Center for Evolutionary Biology and Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Claude Sardet
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), 34298, Montpellier, France
| | - Martine Simonelig
- Institut de Génétique Humaine, CNRS, Université de Montpellier, 34396, Montpellier, France
| | - Bijan Sobhian
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), 34298, Montpellier, France. .,Institut de Génétique Humaine, CNRS, Université de Montpellier, 34396, Montpellier, France.
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40
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Yang Y, Liu S, Egloff S, Eichhorn CD, Hadjian T, Zhen J, Kiss T, Zhou ZH, Feigon J. Structural basis of RNA conformational switching in the transcriptional regulator 7SK RNP. Mol Cell 2022; 82:1724-1736.e7. [PMID: 35320752 PMCID: PMC9081187 DOI: 10.1016/j.molcel.2022.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/27/2021] [Accepted: 02/28/2022] [Indexed: 01/05/2023]
Abstract
7SK non-coding RNA (7SK) negatively regulates RNA polymerase II (RNA Pol II) elongation by inhibiting positive transcription elongation factor b (P-TEFb), and its ribonucleoprotein complex (RNP) is hijacked by HIV-1 for viral transcription and replication. Methylphosphate capping enzyme (MePCE) and La-related protein 7 (Larp7) constitutively associate with 7SK to form a core RNP, while P-TEFb and other proteins dynamically assemble to form different complexes. Here, we present the cryo-EM structures of 7SK core RNP formed with two 7SK conformations, circular and linear, and uncover a common RNA-dependent MePCE-Larp7 complex. Together with NMR, biochemical, and cellular data, these structures reveal the mechanism of MePCE catalytic inactivation in the core RNP, unexpected interactions between Larp7 and RNA that facilitate a role as an RNP chaperone, and that MePCE-7SK-Larp7 core RNP serves as a scaffold for switching between different 7SK conformations essential for RNP assembly and regulation of P-TEFb sequestration and release.
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Affiliation(s)
- Yuan Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shiheng Liu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Sylvain Egloff
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Catherine D Eichhorn
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tanya Hadjian
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - James Zhen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tamás Kiss
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France; Biological Research Centre, Szeged, Temesvári krt. 62, 6726, Hungary
| | - Z Hong Zhou
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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41
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Ta TM, Malik S, Anderson EM, Jones AD, Perchik J, Freylikh M, Sardo L, Klase ZA, Izumi T. Insights Into Persistent HIV-1 Infection and Functional Cure: Novel Capabilities and Strategies. Front Microbiol 2022; 13:862270. [PMID: 35572626 PMCID: PMC9093714 DOI: 10.3389/fmicb.2022.862270] [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: 01/25/2022] [Accepted: 02/21/2022] [Indexed: 12/23/2022] Open
Abstract
Although HIV-1 replication can be efficiently suppressed to undetectable levels in peripheral blood by combination antiretroviral therapy (cART), lifelong medication is still required in people living with HIV (PLWH). Life expectancies have been extended by cART, but age-related comorbidities have increased which are associated with heavy physiological and economic burdens on PLWH. The obstacle to a functional HIV cure can be ascribed to the formation of latent reservoir establishment at the time of acute infection that persists during cART. Recent studies suggest that some HIV reservoirs are established in the early acute stages of HIV infection within multiple immune cells that are gradually shaped by various host and viral mechanisms and may undergo clonal expansion. Early cART initiation has been shown to reduce the reservoir size in HIV-infected individuals. Memory CD4+ T cell subsets are regarded as the predominant cellular compartment of the HIV reservoir, but monocytes and derivative macrophages or dendritic cells also play a role in the persistent virus infection. HIV latency is regulated at multiple molecular levels in transcriptional and post-transcriptional processes. Epigenetic regulation of the proviral promoter can profoundly regulate the viral transcription. In addition, transcriptional elongation, RNA splicing, and nuclear export pathways are also involved in maintaining HIV latency. Although most proviruses contain large internal deletions, some defective proviruses may induce immune activation by expressing viral proteins or producing replication-defective viral-like particles. In this review article, we discuss the state of the art on mechanisms of virus persistence in the periphery and tissue and summarize interdisciplinary approaches toward a functional HIV cure, including novel capabilities and strategies to measure and eliminate the infected reservoirs and induce immune control.
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Affiliation(s)
- Tram M. Ta
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Sajjaf Malik
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Elizabeth M. Anderson
- Office of the Assistant Secretary for Health, Region 3, U.S. Department of Health and Human Services, Washington, DC, United States
| | - Amber D. Jones
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States,Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jocelyn Perchik
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Maryann Freylikh
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Luca Sardo
- Department of Infectious Disease and Vaccines, Merck & Co., Inc., Kenilworth, NJ, United States
| | - Zackary A. Klase
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Neuroimmunology and CNS Therapeutics, Institute of Molecular Medicine and Infectious Diseases, Drexel University of Medicine, Philadelphia, PA, United States
| | - Taisuke Izumi
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States,*Correspondence: Taisuke Izumi,
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42
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Nuclear microRNAs release paused Pol II via the DDX21-CDK9 complex. Cell Rep 2022; 39:110673. [PMID: 35417682 DOI: 10.1016/j.celrep.2022.110673] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/26/2021] [Accepted: 03/22/2022] [Indexed: 11/22/2022] Open
Abstract
RNA activation (RNAa) is an uncharacterized mechanism of transcriptional activation mediated by small RNAs, such as microRNAs (miRNAs). A critical issue in RNAa research is that it is difficult to distinguish between changes in gene expression caused indirectly by post-transcriptional regulation and direct induction of gene expression by RNAa. Therefore, in this study, we seek to identify a key factor involved in RNAa, using the induction of ZMYND10 by miR-34a as a system to evaluate RNAa. We identify the positive transcription elongation factors CDK9 and DDX21, which form a complex with nuclear AGO and TNRC6A, as important transcriptional activators of RNAa. In addition, we find that inhibition of DDX21 suppresses RNAa by miR-34a and other miRNAs without inhibiting post-transcriptional regulation. Our findings reveal a strong connection between RNAa and release of paused Pol II, facilitating RNAa research by making it possible to separately analyze post-transcriptional regulation and RNAa.
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43
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Poly(ADP-ribosylation) of P-TEFb by PARP1 disrupts phase separation to inhibit global transcription after DNA damage. Nat Cell Biol 2022; 24:513-525. [PMID: 35393539 DOI: 10.1038/s41556-022-00872-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 02/20/2022] [Indexed: 12/14/2022]
Abstract
DNA damage shuts down genome-wide transcription to prevent transcriptional mutagenesis and to initiate repair signalling, but the mechanism to stall elongating RNA polymerase II (Pol II) is not fully understood. Central to the DNA damage response, poly(ADP-ribose) polymerase 1 (PARP1) initiates DNA repair by translocating to the lesions where it catalyses protein poly(ADP-ribosylation). Here we report that PARP1 inhibits Pol II elongation by inactivating the transcription elongation factor P-TEFb, a CDK9-cyclin T1 (CycT1) heterodimer. After sensing damage, the activated PARP1 binds to transcriptionally engaged P-TEFb and modifies CycT1 at multiple positions, including histidine residues that are rarely used as an acceptor site. This prevents CycT1 from undergoing liquid-liquid phase separation that is required for CDK9 to hyperphosphorylate Pol II and to stimulate elongation. Functionally, poly(ADP-ribosylation) of CycT1 promotes DNA repair and cell survival. Thus, the P-TEFb-PARP1 signalling plays a protective role in transcription quality control and genomic stability maintenance after DNA damage.
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44
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Olson SW, Turner AMW, Arney JW, Saleem I, Weidmann CA, Margolis DM, Weeks KM, Mustoe AM. Discovery of a large-scale, cell-state-responsive allosteric switch in the 7SK RNA using DANCE-MaP. Mol Cell 2022; 82:1708-1723.e10. [PMID: 35320755 PMCID: PMC9081252 DOI: 10.1016/j.molcel.2022.02.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/29/2021] [Accepted: 02/02/2022] [Indexed: 12/17/2022]
Abstract
7SK is a conserved noncoding RNA that regulates transcription by sequestering the transcription factor P-TEFb. 7SK function entails complex changes in RNA structure, but characterizing RNA dynamics in cells remains an unsolved challenge. We developed a single-molecule chemical probing strategy, DANCE-MaP (deconvolution and annotation of ribonucleic conformational ensembles), that defines per-nucleotide reactivity, direct base pairing interactions, tertiary interactions, and thermodynamic populations for each state in RNA structural ensembles from a single experiment. DANCE-MaP reveals that 7SK RNA encodes a large-scale structural switch that couples dissolution of the P-TEFb binding site to structural remodeling at distal release factor binding sites. The 7SK structural equilibrium shifts in response to cell growth and stress and can be targeted to modulate expression of P-TEFbresponsive genes. Our study reveals that RNA structural dynamics underlie 7SK function as an integrator of diverse cellular signals to control transcription and establishes the power of DANCE-MaP to define RNA dynamics in cells.
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Affiliation(s)
- Samuel W Olson
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Anne-Marie W Turner
- Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; UNC HIV Cure Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - J Winston Arney
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Irfana Saleem
- Verna and Marrs McClean Department of Biochemistry and Molecular Biology, Therapeutic Innovation Center (THINC), Baylor College of Medicine, Houston, TX 77030, USA
| | - Chase A Weidmann
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - David M Margolis
- Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; UNC HIV Cure Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kevin M Weeks
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA.
| | - Anthony M Mustoe
- Verna and Marrs McClean Department of Biochemistry and Molecular Biology, Therapeutic Innovation Center (THINC), Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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45
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The methyl phosphate capping enzyme Bmc1/Bin3 is a stable component of the fission yeast telomerase holoenzyme. Nat Commun 2022; 13:1277. [PMID: 35277511 PMCID: PMC8917221 DOI: 10.1038/s41467-022-28985-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 02/11/2022] [Indexed: 12/13/2022] Open
Abstract
The telomerase holoenzyme is critical for maintaining eukaryotic genome integrity. In addition to a reverse transcriptase and an RNA template, telomerase contains additional proteins that protect the telomerase RNA and promote holoenzyme assembly. Here we report that the methyl phosphate capping enzyme (MePCE) Bmc1/Bin3 is a stable component of the S. pombe telomerase holoenzyme. Bmc1 associates with the telomerase holoenzyme and U6 snRNA through an interaction with the recently described LARP7 family member Pof8, and we demonstrate that these two factors are evolutionarily linked in fungi. Our data suggest that the association of Bmc1 with telomerase is independent of its methyltransferase activity, but rather that Bmc1 functions in telomerase holoenzyme assembly by promoting TER1 accumulation and Pof8 recruitment to TER1. Taken together, this work yields new insight into the composition, assembly, and regulation of the telomerase holoenzyme in fission yeast as well as the breadth of its evolutionary conservation.
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Chemical reversible crosslinking enables measurement of RNA 3D distances and alternative conformations in cells. Nat Commun 2022; 13:911. [PMID: 35177610 PMCID: PMC8854666 DOI: 10.1038/s41467-022-28602-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 01/19/2022] [Indexed: 02/06/2023] Open
Abstract
Three-dimensional (3D) structures dictate the functions of RNA molecules in a wide variety of biological processes. However, direct determination of RNA 3D structures in vivo is difficult due to their large sizes, conformational heterogeneity, and dynamics. Here we present a method, Spatial 2′-Hydroxyl Acylation Reversible Crosslinking (SHARC), which uses chemical crosslinkers of defined lengths to measure distances between nucleotides in cellular RNA. Integrating crosslinking, exonuclease (exo) trimming, proximity ligation, and high throughput sequencing, SHARC enables transcriptome-wide tertiary structure contact maps at high accuracy and precision, revealing heterogeneous RNA structures and interactions. SHARC data provide constraints that improves Rosetta-based RNA 3D structure modeling at near-nanometer resolution. Integrating SHARC-exo with other crosslinking-based methods, we discover compact folding of the 7SK RNA, a critical regulator of transcriptional elongation. These results establish a strategy for measuring RNA 3D distances and alternative conformations in their native cellular context. Determination of RNA 3D structures in vivo is a challenging problem. Here, the authors describe a chemical crosslinking method (SHARC) that they use in combination with RNA sequencing to measure distances between nucleotides in RNA 3D structures.
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Computer-aided comprehensive explorations of RNA structural polymorphism through complementary simulation methods. QRB DISCOVERY 2022. [PMID: 37529277 PMCID: PMC10392686 DOI: 10.1017/qrd.2022.19] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
While RNA folding was originally seen as a simple problem to solve, it has been shown that the promiscuous interactions of the nucleobases result in structural polymorphism, with several competing structures generally observed for non-coding RNA. This inherent complexity limits our understanding of these molecules from experiments alone, and computational methods are commonly used to study RNA. Here, we discuss three advanced sampling schemes, namely Hamiltonian-replica exchange molecular dynamics (MD), ratchet-and-pawl MD and discrete path sampling, as well as the HiRE-RNA coarse-graining scheme, and highlight how these approaches are complementary with reference to recent case studies. While all computational methods have their shortcomings, the plurality of simulation methods leads to a better understanding of experimental findings and can inform and guide experimental work on RNA polymorphism.
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The non-apoptotic function of Caspase-8 in negatively regulating the CDK9-mediated Ser2 phosphorylation of RNA polymerase II in cervical cancer. Cell Mol Life Sci 2022; 79:597. [PMID: 36399280 PMCID: PMC9674771 DOI: 10.1007/s00018-022-04598-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/11/2022] [Accepted: 10/13/2022] [Indexed: 11/19/2022]
Abstract
Cervical cancer is the fourth most frequently diagnosed and fatal gynecological cancer. 15-61% of all cases metastasize and develop chemoresistance, reducing the 5-year survival of cervical cancer patients to as low as 17%. Therefore, unraveling the mechanisms contributing to metastasis is critical in developing better-targeted therapies against it. Here, we have identified a novel mechanism where nuclear Caspase-8 directly interacts with and inhibits the activity of CDK9, thereby modulating RNAPII-mediated global transcription, including those of cell-migration- and cell-invasion-associated genes. Crucially, low Caspase-8 expression in cervical cancer patients leads to poor prognosis, higher CDK9 phosphorylation at Thr186, and increased RNAPII activity in cervical cancer cell lines and patient biopsies. Caspase-8 knock-out cells were also more resistant to the small-molecule CDK9 inhibitor BAY1251152 in both 2D- and 3D-culture conditions. Combining BAY1251152 with Cisplatin synergistically overcame chemoresistance of Caspase-8-deficient cervical cancer cells. Therefore, Caspase-8 expression could be a marker in chemoresistant cervical tumors, suggesting CDK9 inhibitor treatment for their sensitization to Cisplatin-based chemotherapy.
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Liu Y, Li L, Timani K, White C, He JJ. Tip110 Expression Facilitates the Release of HEXIM1 and pTEFb from the 7SK Ribonucleoprotein Complex Involving Regulation of the Intracellular Redox Level. Aging Dis 2021; 12:2113-2124. [PMID: 34881089 PMCID: PMC8612609 DOI: 10.14336/ad.2021.0528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/28/2021] [Indexed: 11/18/2022] Open
Abstract
HIV-1 Tat-interacting protein of 110 kDa (Tip110; p110nrb/SART3) has been identified to be important for HIV gene transcription and several host gene expression. In this study, we showed that Tip110 was present in the 7SK snRNP through direct binding to MEPCE, a component of the 7SK snRNP complex. In addition, we found a positive association between Tip110 expression, change of HEXIM1 from dimer/oligomer to monomer, and release of HEXIM1 and P-TEFb from the 7SK snRNP complex. A similar association was also noted specifically in nuclear matrix as well as in chromatin where the free HEXIM1 and 7SK snRNP-bound HEXIM1 are located. Moreover, we demonstrated that Tip110 expression was linked to the glutathione metabolic pathway and the intracellular redox level, which in turn regulated HEXIM1 dimerization/oligomerization. Lastly, we performed the FRET microscopic analysis and confirmed the direct relationship between Tip110 expression and HEXIM1 dimerization/oligomerization in vivo. Taken together, these results identified a new mechanism governing HEXIM1 dimerization/oligomerization and the release of HEXIM1 and P-TEFb from the 7SK snRNP complex. These results also yield new insights to the roles of Tip110 in HIV gene transcription and replication.
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Affiliation(s)
- Ying Liu
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
| | - Lu Li
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
| | - Khalid Timani
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
| | - Carl White
- 2Center for Cancer Cell Biology, Immunology and Infection, and.,3Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Johnny J He
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
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Acchioni C, Palermo E, Sandini S, Acchioni M, Hiscott J, Sgarbanti M. Fighting HIV-1 Persistence: At the Crossroads of "Shoc-K and B-Lock". Pathogens 2021; 10:pathogens10111517. [PMID: 34832672 PMCID: PMC8622007 DOI: 10.3390/pathogens10111517] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/10/2021] [Accepted: 11/17/2021] [Indexed: 12/12/2022] Open
Abstract
Despite the success of highly active antiretroviral therapy (HAART), integrated HIV-1 proviral DNA cannot be eradicated from an infected individual. HAART is not able to eliminate latently infected cells that remain invisible to the immune system. Viral sanctuaries in specific tissues and immune-privileged sites may cause residual viral replication that contributes to HIV-1 persistence. The “Shock or Kick, and Kill” approach uses latency reversing agents (LRAs) in the presence of HAART, followed by cell-killing due to viral cytopathic effects and immune-mediated clearance. Different LRAs may be required for the in vivo reactivation of HIV-1 in different CD4+ T cell reservoirs, leading to the activation of cellular transcription factors acting on the integrated proviral HIV-1 LTR. An important requirement for LRA drugs is the reactivation of viral transcription and replication without causing a generalized immune activation. Toll-like receptors, RIG-I like receptors, and STING agonists have emerged recently as a new class of LRAs that augment selective apoptosis in reactivated T lymphocytes. The challenge is to extend in vitro observations to HIV-1 positive patients. Further studies are also needed to overcome the mechanisms that protect latently infected cells from reactivation and/or elimination by the immune system. The Block and Lock alternative strategy aims at using latency promoting/inducing agents (LPAs/LIAs) to block the ability of latent proviruses to reactivate transcription in order to achieve a long term lock down of potential residual virus replication. The Shock and Kill and the Block and Lock approaches may not be only alternative to each other, but, if combined together (one after the other), or given all at once [namely “Shoc-K(kill) and B(block)-Lock”], they may represent a better approach to a functional cure.
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Affiliation(s)
- Chiara Acchioni
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy; (C.A.); (S.S.); (M.A.)
| | - Enrico Palermo
- Istituto Pasteur Italia—Cenci Bolognetti Foundation, Viale Regina Elena 291, 00161 Rome, Italy; (E.P.); (J.H.)
| | - Silvia Sandini
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy; (C.A.); (S.S.); (M.A.)
| | - Marta Acchioni
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy; (C.A.); (S.S.); (M.A.)
| | - John Hiscott
- Istituto Pasteur Italia—Cenci Bolognetti Foundation, Viale Regina Elena 291, 00161 Rome, Italy; (E.P.); (J.H.)
| | - Marco Sgarbanti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy; (C.A.); (S.S.); (M.A.)
- Correspondence: ; Tel.: +39-06-4990-3266
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