1
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Walker RL, Hornicek FJ, Duan Z. Transcriptional regulation and therapeutic potential of cyclin-dependent kinase 9 (CDK9) in sarcoma. Biochem Pharmacol 2024; 226:116342. [PMID: 38848777 DOI: 10.1016/j.bcp.2024.116342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/17/2024] [Accepted: 06/04/2024] [Indexed: 06/09/2024]
Abstract
Sarcomas include various subtypes comprising two significant groups - soft tissue and bone sarcomas. Although the survival rate for some sarcoma subtypes has improved over time, the current methods of treatment remain efficaciously limited, as recurrent, and metastatic diseases remain a major obstacle. There is a need for better options and therapeutic strategies in treating sarcoma. Cyclin dependent kinase 9 (CDK9) is a transcriptional kinase and has emerged as a promising target for treating various cancers. The aberrant expression and activation of CDK9 have been observed in several sarcoma subtypes, including rhabdomyosarcoma, synovial sarcoma, osteosarcoma, Ewing sarcoma, and chordoma. Enhanced CDK9 expression has also been correlated with poorer prognosis in sarcoma patients. As a master regulator of transcription, CDK9 promotes transcription elongation by phosphorylation and releasing RNA polymerase II (RNAPII) from its promoter proximal pause. Release of RNAPII from this pause induces transcription of critical genes in the tumor cell. Overexpression and activation of CDK9 have been observed to lead to the expression of oncogenes, including MYC and MCL-1, that aid sarcoma development and progression. Inhibition of CDK9 in sarcoma has been proven to reduce these oncogenes' expression and decrease proliferation and growth in different sarcoma cells. Currently, there are several CDK9 inhibitors in preclinical and clinical investigations. This review aims to highlight the recent discovery and results on the transcriptional role and therapeutic potential of CDK9 in sarcoma.
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Affiliation(s)
- Robert L Walker
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA
| | - Francis J Hornicek
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA
| | - Zhenfeng Duan
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA.
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2
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Sabath K, Nabih A, Arnold C, Moussa R, Domjan D, Zaugg JB, Jonas S. Basis of gene-specific transcription regulation by the Integrator complex. Mol Cell 2024; 84:2525-2541.e12. [PMID: 38906142 DOI: 10.1016/j.molcel.2024.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 03/04/2024] [Accepted: 05/29/2024] [Indexed: 06/23/2024]
Abstract
The Integrator complex attenuates gene expression via the premature termination of RNA polymerase II (RNAP2) at promoter-proximal pausing sites. It is required for stimulus response, cell differentiation, and neurodevelopment, but how gene-specific and adaptive regulation by Integrator is achieved remains unclear. Here, we identify two sites on human Integrator subunits 13/14 that serve as binding hubs for sequence-specific transcription factors (TFs) and other transcription effector complexes. When Integrator is attached to paused RNAP2, these hubs are positioned upstream of the transcription bubble, consistent with simultaneous TF-promoter tethering. The TFs co-localize with Integrator genome-wide, increase Integrator abundance on target genes, and co-regulate responsive transcriptional programs. For instance, sensory cilia formation induced by glucose starvation depends on Integrator-TF contacts. Our data suggest TF-mediated promoter recruitment of Integrator as a widespread mechanism for targeted transcription regulation.
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Affiliation(s)
- Kevin Sabath
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.
| | - Amena Nabih
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Christian Arnold
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Rim Moussa
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - David Domjan
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Judith B Zaugg
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Stefanie Jonas
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.
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3
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Walker FM, Sobral LM, Danis E, Sanford B, Donthula S, Balakrishnan I, Wang D, Pierce A, Karam SD, Kargar S, Serkova NJ, Foreman NK, Venkataraman S, Dowell R, Vibhakar R, Dahl NA. Rapid P-TEFb-dependent transcriptional reorganization underpins the glioma adaptive response to radiotherapy. Nat Commun 2024; 15:4616. [PMID: 38816355 PMCID: PMC11139976 DOI: 10.1038/s41467-024-48214-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 04/23/2024] [Indexed: 06/01/2024] Open
Abstract
Dynamic regulation of gene expression is fundamental for cellular adaptation to exogenous stressors. P-TEFb-mediated pause-release of RNA polymerase II (Pol II) is a conserved regulatory mechanism for synchronous transcriptional induction in response to heat shock, but this pro-survival role has not been examined in the applied context of cancer therapy. Using model systems of pediatric high-grade glioma, we show that rapid genome-wide reorganization of active chromatin facilitates P-TEFb-mediated nascent transcriptional induction within hours of exposure to therapeutic ionizing radiation. Concurrent inhibition of P-TEFb disrupts this chromatin reorganization and blunts transcriptional induction, abrogating key adaptive programs such as DNA damage repair and cell cycle regulation. This combination demonstrates a potent, synergistic therapeutic potential agnostic of glioma subtype, leading to a marked induction of tumor cell apoptosis and prolongation of xenograft survival. These studies reveal a central role for P-TEFb underpinning the early adaptive response to radiotherapy, opening avenues for combinatorial treatment in these lethal malignancies.
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Affiliation(s)
- Faye M Walker
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Lays Martin Sobral
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Etienne Danis
- Department of Biomedical Informatics, University of Colorado School of Medicine, Aurora, CO, USA
- University of Colorado Cancer Center, University of Colorado School of Medicine, Aurora, CO, USA
| | - Bridget Sanford
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sahiti Donthula
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ilango Balakrishnan
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Dong Wang
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Angela Pierce
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sana D Karam
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Soudabeh Kargar
- University of Colorado Cancer Center, University of Colorado School of Medicine, Aurora, CO, USA
| | - Natalie J Serkova
- Department of Radiology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Nicholas K Foreman
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- Center for Cancer and Blood Disorders, Children's Hospital Colorado, Aurora, CO, USA
- Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sujatha Venkataraman
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Robin Dowell
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado, Boulder, CO, USA
| | - Rajeev Vibhakar
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- Center for Cancer and Blood Disorders, Children's Hospital Colorado, Aurora, CO, USA
- Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Nathan A Dahl
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA.
- Center for Cancer and Blood Disorders, Children's Hospital Colorado, Aurora, CO, USA.
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4
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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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5
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Yao Z, Song P, Jiao W. Pathogenic role of super-enhancers as potential therapeutic targets in lung cancer. Front Pharmacol 2024; 15:1383580. [PMID: 38681203 PMCID: PMC11047458 DOI: 10.3389/fphar.2024.1383580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/02/2024] [Indexed: 05/01/2024] Open
Abstract
Lung cancer is still one of the deadliest malignancies today, and most patients with advanced lung cancer pass away from disease progression that is uncontrollable by medications. Super-enhancers (SEs) are large clusters of enhancers in the genome's non-coding sequences that actively trigger transcription. Although SEs have just been identified over the past 10 years, their intricate structure and crucial role in determining cell identity and promoting tumorigenesis and progression are increasingly coming to light. Here, we review the structural composition of SEs, the auto-regulatory circuits, the control mechanisms of downstream genes and pathways, and the characterization of subgroups classified according to SEs in lung cancer. Additionally, we discuss the therapeutic targets, several small-molecule inhibitors, and available treatment options for SEs in lung cancer. Combination therapies have demonstrated considerable advantages in preclinical models, and we anticipate that these drugs will soon enter clinical studies and benefit patients.
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Affiliation(s)
- Zhiyuan Yao
- Department of Thoracic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Peng Song
- Department of Thoracic Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Wenjie Jiao
- Department of Thoracic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
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6
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Zhang Y, Shan L, Tang W, Ge Y, Li C, Zhang J. Recent Discovery and Development of Inhibitors that Target CDK9 and Their Therapeutic Indications. J Med Chem 2024; 67:5185-5215. [PMID: 38564299 DOI: 10.1021/acs.jmedchem.4c00312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
CDK9 is a cyclin-dependent kinase that plays pivotal roles in multiple cellular functions including gene transcription, cell cycle regulation, DNA damage repair, and cellular differentiation. Targeting CDK9 is considered an attractive strategy for antitumor therapy, especially for leukemia and lymphoma. Several potent small molecule inhibitors, exemplified by TG02 (4), have progressed to clinical trials. However, many of them face challenges such as low clinical efficacy and multiple adverse reactions and may necessitate the exploration of novel strategies to lead to success in the clinic. In this perspective, we present a comprehensive overview of the structural characteristics, biological functions, and preclinical status of CDK9 inhibitors. Our focus extends to various types of inhibitors, including pan-inhibitors, selective inhibitors, dual-target inhibitors, degraders, PPI inhibitors, and natural products. The discussion encompasses chemical structures, structure-activity relationships (SARs), biological activities, selectivity, and therapeutic potential, providing detailed insight into the diverse landscape of CDK9 inhibitors.
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Affiliation(s)
- Yuming Zhang
- Department of Neurology, Neuro-system and Multimorbidity Laboratory and State Key Laboratory of Biotherapy and Cancer Center and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan, China
- West China College of Medicine, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan, China
| | - Lianhai Shan
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031 Sichuan, China
| | - Wentao Tang
- Department of Neurology, Neuro-system and Multimorbidity Laboratory and State Key Laboratory of Biotherapy and Cancer Center and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan, China
| | - Yating Ge
- Department of Neurology, Neuro-system and Multimorbidity Laboratory and State Key Laboratory of Biotherapy and Cancer Center and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan, China
| | - ChengXian Li
- Department of Neurology, Neuro-system and Multimorbidity Laboratory and State Key Laboratory of Biotherapy and Cancer Center and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan, China
| | - Jifa Zhang
- Department of Neurology, Neuro-system and Multimorbidity Laboratory and State Key Laboratory of Biotherapy and Cancer Center and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan, China
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7
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Stec N, Klosin A. Transcriptional bodies manage tight resources. Nat Cell Biol 2024; 26:512-513. [PMID: 38589532 DOI: 10.1038/s41556-024-01395-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Affiliation(s)
- Natalia Stec
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Adam Klosin
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
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8
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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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9
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Koirala M, DiPaola M. Targeting CDK9 in Cancer: An Integrated Approach of Combining In Silico Screening with Experimental Validation for Novel Degraders. Curr Issues Mol Biol 2024; 46:1713-1730. [PMID: 38534727 DOI: 10.3390/cimb46030111] [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: 01/04/2024] [Revised: 02/08/2024] [Accepted: 02/20/2024] [Indexed: 03/28/2024] Open
Abstract
The persistent threat of cancer remains a significant hurdle for global health, prompting the exploration of innovative approaches in the quest for successful therapeutic interventions. Cyclin-dependent kinase 9 (CDK9), a central player in transcription regulation and cell cycle progression, has emerged as a promising target to combat cancer. Its pivotal role in oncogenic pathways and the pressing need for novel cancer treatments has propelled CDK9 into the spotlight of drug discovery efforts. This article presents a comprehensive study that connects a multidisciplinary approach, combining computational methodologies, experimental validation, and the transformative Proteolysis-Targeting Chimera (PROTAC) technology. By uniting these diverse techniques, we aim to identify, characterize, and optimize a new class of degraders targeting CDK9. We explore these compounds for targeted protein degradation, offering a novel and potentially effective approach to cancer therapy. This cohesive strategy utilizes the combination of computational predictions and experimental insights, with the goal of advancing the development of effective anticancer therapeutics, targeting CDK9.
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10
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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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11
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Archuleta SR, Goodrich JA, Kugel JF. Mechanisms and Functions of the RNA Polymerase II General Transcription Machinery during the Transcription Cycle. Biomolecules 2024; 14:176. [PMID: 38397413 PMCID: PMC10886972 DOI: 10.3390/biom14020176] [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: 12/21/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Central to the development and survival of all organisms is the regulation of gene expression, which begins with the process of transcription catalyzed by RNA polymerases. During transcription of protein-coding genes, the general transcription factors (GTFs) work alongside RNA polymerase II (Pol II) to assemble the preinitiation complex at the transcription start site, open the promoter DNA, initiate synthesis of the nascent messenger RNA, transition to productive elongation, and ultimately terminate transcription. Through these different stages of transcription, Pol II is dynamically phosphorylated at the C-terminal tail of its largest subunit, serving as a control mechanism for Pol II elongation and a signaling/binding platform for co-transcriptional factors. The large number of core protein factors participating in the fundamental steps of transcription add dense layers of regulation that contribute to the complexity of temporal and spatial control of gene expression within any given cell type. The Pol II transcription system is highly conserved across different levels of eukaryotes; however, most of the information here will focus on the human Pol II system. This review walks through various stages of transcription, from preinitiation complex assembly to termination, highlighting the functions and mechanisms of the core machinery that participates in each stage.
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Affiliation(s)
| | - James A. Goodrich
- Department of Biochemistry, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA;
| | - Jennifer F. Kugel
- Department of Biochemistry, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA;
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12
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Dunn LEM, Birkenheuer CH, Baines JD. A Revision of Herpes Simplex Virus Type 1 Transcription: First, Repress; Then, Express. Microorganisms 2024; 12:262. [PMID: 38399666 PMCID: PMC10892140 DOI: 10.3390/microorganisms12020262] [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: 12/15/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The herpes virus genome bears more than 80 strong transcriptional promoters. Upon entry into the host cell nucleus, these genes are transcribed in an orderly manner, producing five immediate-early (IE) gene products, including ICP0, ICP4, and ICP22, while non-IE genes are mostly silent. The IE gene products are necessary for the transcription of temporal classes following sequentially as early, leaky late, and true late. A recent analysis using precision nuclear run-on followed by deep sequencing (PRO-seq) has revealed an important step preceding all HSV-1 transcription. Specifically, the immediate-early proteins ICP4 and ICP0 enter the cell with the incoming genome to help preclude the nascent antisense, intergenic, and sense transcription of all viral genes. VP16, which is also delivered into the nucleus upon entry, almost immediately reverses this repression on IE genes. The resulting de novo expression of ICP4 and ICP22 further repress antisense, intergenic, and early and late viral gene transcription through different mechanisms before the sequential de-repression of these gene classes later in infection. This early repression, termed transient immediate-early protein-mediated repression (TIEMR), precludes unproductive, antisense, intergenic, and late gene transcription early in infection to ensure the efficient and orderly progression of the viral cascade.
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Affiliation(s)
- Laura E M Dunn
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
| | - Claire H Birkenheuer
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
| | - Joel D Baines
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
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Xu H, Wu D, Xiao M, Lei Y, Lei Y, Yu X, Shi S. PP2A complex disruptor SET prompts widespread hypertranscription of growth-essential genes in the pancreatic cancer cells. SCIENCE ADVANCES 2024; 10:eadk6633. [PMID: 38277454 PMCID: PMC10816699 DOI: 10.1126/sciadv.adk6633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/26/2023] [Indexed: 01/28/2024]
Abstract
Hyperactivation of the oncogenic transcription reflects the epigenetic plasticity of the cancer cells. Su(var)3-9, enhancer of zeste, Trithorax (SET) was described as a nuclear factor that stimulated transcription from the chromatin template. However, the mechanisms of SET-dependent transcription are unknown. Here, we found that overexpression of SET and CDK9 induced very similar transcriptome signatures in multiple cancer cell lines. SET localized in the transcription start site (TSS)-proximal regions and supported the RNA transcription. SET specifically bound the PP2A-C subunit and induced PP2A-A subunit repulsion from the C subunit, which indicated the role of SET as a PP2A-A/C complex disruptor in the TSS-proximal regions. Through blocking PP2A activity, SET assisted CDK9 to maintain Pol II CTD phosphorylation and activated mRNA transcription. Our findings position SET as a key factor that modulates chromatin PP2A activity, promoting the oncogenic transcription in the pancreatic cancer.
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Affiliation(s)
- He Xu
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
- Shanghai Pancreatic Cancer Institute, Shanghai 200032, China
- Pancreatic Cancer Institute, Fudan University, Shanghai 200032, China
| | - Di Wu
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
- Shanghai Pancreatic Cancer Institute, Shanghai 200032, China
- Pancreatic Cancer Institute, Fudan University, Shanghai 200032, China
| | - Mingming Xiao
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
- Shanghai Pancreatic Cancer Institute, Shanghai 200032, China
- Pancreatic Cancer Institute, Fudan University, Shanghai 200032, China
| | - Yubin Lei
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang Province 310024, China
| | - Yalan Lei
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
- Shanghai Pancreatic Cancer Institute, Shanghai 200032, China
- Pancreatic Cancer Institute, Fudan University, Shanghai 200032, China
| | - Xianjun Yu
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
- Shanghai Pancreatic Cancer Institute, Shanghai 200032, China
- Pancreatic Cancer Institute, Fudan University, Shanghai 200032, China
| | - Si Shi
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
- Shanghai Pancreatic Cancer Institute, Shanghai 200032, China
- Pancreatic Cancer Institute, Fudan University, Shanghai 200032, China
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14
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Zhou D, Yu Q, Janssens RC, Marteijn JA. Live-cell imaging of endogenous CSB-mScarletI as a sensitive marker for DNA-damage-induced transcription stress. CELL REPORTS METHODS 2024; 4:100674. [PMID: 38176411 PMCID: PMC10831951 DOI: 10.1016/j.crmeth.2023.100674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/13/2023] [Accepted: 12/11/2023] [Indexed: 01/06/2024]
Abstract
Transcription by RNA polymerase II (RNA Pol II) is crucial for cellular function, but DNA damage severely impedes this process. Thus far, transcription-blocking DNA lesions (TBLs) and their repair have been difficult to quantify in living cells. To overcome this, we generated, using CRISPR-Cas9-mediated gene editing, mScarletI-tagged Cockayne syndrome group B protein (CSB) and UV-stimulated scaffold protein A (UVSSA) knockin cells. These cells allowed us to study the binding dynamics of CSB and UVSSA to lesion-stalled RNA Pol II using fluorescence recovery after photobleaching (FRAP). We show that especially CSB mobility is a sensitive transcription stress marker at physiologically relevant DNA damage levels. Transcription-coupled nucleotide excision repair (TC-NER)-mediated repair can be assessed by studying CSB immobilization over time. Additionally, flow cytometry reveals the regulation of CSB protein levels by CRL4CSA-mediated ubiquitylation and deubiquitylation by USP7. This approach allows the sensitive detection of TBLs and their repair and the study of TC-NER complex assembly and stability in living cells.
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Affiliation(s)
- Di Zhou
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Qing Yu
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Roel C Janssens
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Jurgen A Marteijn
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands.
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15
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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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Liu H, Fu H, Yu C, Zhang N, Huang C, Lv L, Hu C, Chen F, Xiao Z, Zhang Z, Lu H, Yuan K. Transcriptional pausing induced by ionizing radiation enables the acquisition of radioresistance in nasopharyngeal carcinoma. J Mol Cell Biol 2024; 15:mjad044. [PMID: 37407287 PMCID: PMC10960568 DOI: 10.1093/jmcb/mjad044] [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: 11/25/2022] [Revised: 03/24/2023] [Accepted: 07/04/2023] [Indexed: 07/07/2023] Open
Abstract
Lesions on the DNA template can impact transcription via distinct regulatory pathways. Ionizing radiation (IR) as the mainstay modality for many malignancies elicits most of the cytotoxicity by inducing a variety of DNA damages in the genome. How the IR treatment alters the transcription cycle and whether it contributes to the development of radioresistance remain poorly understood. Here, we report an increase in the paused RNA polymerase II (RNAPII), as indicated by the phosphorylation at serine 5 residue of its C-terminal domain, in recurrent nasopharyngeal carcinoma (NPC) patient samples after IR treatment and cultured NPC cells developing IR resistance. Reducing the pool of paused RNAPII by either inhibiting TFIIH-associated CDK7 or stimulating the positive transcription elongation factor b, a CDK9-CycT1 heterodimer, attenuates IR resistance of NPC cells. Interestingly, the poly(ADP-ribosyl)ation of CycT1, which disrupts its phase separation, is elevated in the IR-resistant cells. Mutation of the major poly(ADP-ribosyl)ation sites of CycT1 decreases RNAPII pausing and restores IR sensitivity. Genome-wide chromatin immunoprecipitation followed by sequencing analyses reveal that several genes involved in radiation response and cell cycle control are subject to the regulation imposed by the paused RNAPII. Particularly, we identify the NIMA-related kinase NEK7 under such regulation as a new radioresistance factor, whose downregulation results in the increased chromosome instability, enabling the development of IR resistance. Overall, our results highlight a novel link between the alteration in the transcription cycle and the acquisition of IR resistance, opening up new opportunities to increase the efficacy of radiotherapy and thwart radioresistance in NPC.
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Affiliation(s)
- Honglu Liu
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Huanyi Fu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Chunhong Yu
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Na Zhang
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Canhua Huang
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Lu Lv
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, China
| | - Chunhong Hu
- Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Fang Chen
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, China
| | - Zhiqiang Xiao
- Research Center of Carcinogenesis and Targeted Therapy, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Zhuohua Zhang
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Huasong Lu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Kai Yuan
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
- The Biobank of Xiangya Hospital, Central South University, Changsha 410008, China
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17
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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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18
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Hunt G, Vaid R, Pirogov S, Pfab A, Ziegenhain C, Sandberg R, Reimegård J, Mannervik M. Tissue-specific RNA Polymerase II promoter-proximal pause release and burst kinetics in a Drosophila embryonic patterning network. Genome Biol 2024; 25:2. [PMID: 38166964 PMCID: PMC10763363 DOI: 10.1186/s13059-023-03135-0] [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: 02/19/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Formation of tissue-specific transcriptional programs underlies multicellular development, including dorsoventral (DV) patterning of the Drosophila embryo. This involves interactions between transcriptional enhancers and promoters in a chromatin context, but how the chromatin landscape influences transcription is not fully understood. RESULTS Here we comprehensively resolve differential transcriptional and chromatin states during Drosophila DV patterning. We find that RNA Polymerase II pausing is established at DV promoters prior to zygotic genome activation (ZGA), that pausing persists irrespective of cell fate, but that release into productive elongation is tightly regulated and accompanied by tissue-specific P-TEFb recruitment. DV enhancers acquire distinct tissue-specific chromatin states through CBP-mediated histone acetylation that predict the transcriptional output of target genes, whereas promoter states are more tissue-invariant. Transcriptome-wide inference of burst kinetics in different cell types revealed that while DV genes are generally characterized by a high burst size, either burst size or frequency can differ between tissues. CONCLUSIONS The data suggest that pausing is established by pioneer transcription factors prior to ZGA and that release from pausing is imparted by enhancer chromatin state to regulate bursting in a tissue-specific manner in the early embryo. Our results uncover how developmental patterning is orchestrated by tissue-specific bursts of transcription from Pol II primed promoters in response to enhancer regulatory cues.
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Affiliation(s)
- George Hunt
- Department Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Roshan Vaid
- Department Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Sergei Pirogov
- Department Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Alexander Pfab
- Department Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | | | - Rickard Sandberg
- Department Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Johan Reimegård
- Department Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Mattias Mannervik
- Department Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
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19
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Long Q, Xiang M, Xiao L, Wang J, Guan X, Liu J, Liao C. The Biological Significance of AFF4: Promoting Transcription Elongation, Osteogenic Differentiation and Tumor Progression. Comb Chem High Throughput Screen 2024; 27:1403-1412. [PMID: 37815186 DOI: 10.2174/0113862073241079230920082056] [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: 12/20/2022] [Revised: 06/23/2023] [Accepted: 07/27/2023] [Indexed: 10/11/2023]
Abstract
As a member of the AF4/FMR2 (AFF) family, AFF4 is a scaffold protein in the superelongation complex (SEC). In this mini-view, we discuss the role of AFF4 as a transcription elongation factor that mediates HIV activation and replication and stem cell osteogenic differentiation. AFF4 also promotes the progression of head and neck squamous cell carcinoma, leukemia, breast cancer, bladder cancer and other malignant tumors. The biological function of AFF4 is largely achieved through SEC assembly, regulates SRY-box transcription factor 2 (SOX2), MYC, estrogen receptor alpha (ESR1), inhibitor of differentiation 1 (ID1), c-Jun and noncanonical nuclear factor-κB (NF-κB) transcription and combines with fusion in sarcoma (FUS), unique regulatory cyclins (CycT1), or mixed lineage leukemia (MLL). We explore the prospects of using AFF4 as a therapeutic in Acquired immunodeficiency syndrome (AIDS) and malignant tumors and its potential as a stemness regulator.
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Affiliation(s)
- Qian Long
- Department of Orthodontics II, Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, 563000, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, 563006, China
| | - Mingli Xiang
- Department of Orthodontics II, Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, 563000, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, 563006, China
| | - Linlin Xiao
- Department of Orthodontics II, Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, 563000, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, 563006, China
| | - Jiajia Wang
- Department of Orthodontics II, Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, 563000, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, 563006, China
| | - Xiaoyan Guan
- Department of Orthodontics II, Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, 563000, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, 563006, China
| | - Jianguo Liu
- Department of Orthodontics II, Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, 563000, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, 563006, China
| | - Chengcheng Liao
- Department of Orthodontics II, Affiliated Stomatological Hospital of Zunyi Medical University, Zunyi, 563000, China
- Oral Disease Research Key Laboratory of Guizhou Tertiary Institution, School of Stomatology, Zunyi Medical University, Zunyi, 563006, China
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20
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Russo M, Piccolo V, Polizzese D, Prosperini E, Borriero C, Polletti S, Bedin F, Marenda M, Michieletto D, Mandana GM, Rodighiero S, Cuomo A, Natoli G. Restrictor synergizes with Symplekin and PNUTS to terminate extragenic transcription. Genes Dev 2023; 37:1017-1040. [PMID: 38092518 PMCID: PMC10760643 DOI: 10.1101/gad.351057.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 11/29/2023] [Indexed: 12/28/2023]
Abstract
Transcription termination pathways mitigate the detrimental consequences of unscheduled promiscuous initiation occurring at hundreds of thousands of genomic cis-regulatory elements. The Restrictor complex, composed of the Pol II-interacting protein WDR82 and the RNA-binding protein ZC3H4, suppresses processive transcription at thousands of extragenic sites in mammalian genomes. Restrictor-driven termination does not involve nascent RNA cleavage, and its interplay with other termination machineries is unclear. Here we show that efficient termination at Restrictor-controlled extragenic transcription units involves the recruitment of the protein phosphatase 1 (PP1) regulatory subunit PNUTS, a negative regulator of the SPT5 elongation factor, and Symplekin, a protein associated with RNA cleavage complexes but also involved in cleavage-independent and phosphatase-dependent termination of noncoding RNAs in yeast. PNUTS and Symplekin act synergistically with, but independently from, Restrictor to dampen processive extragenic transcription. Moreover, the presence of limiting nuclear levels of Symplekin imposes a competition for its recruitment among multiple transcription termination machineries, resulting in mutual regulatory interactions. Hence, by synergizing with Restrictor, Symplekin and PNUTS enable efficient termination of processive, long-range extragenic transcription.
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Affiliation(s)
- Marta Russo
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Viviana Piccolo
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Danilo Polizzese
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Elena Prosperini
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Carolina Borriero
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Sara Polletti
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Fabio Bedin
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Mattia Marenda
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Davide Michieletto
- School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Gaurav Madappa Mandana
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Simona Rodighiero
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Alessandro Cuomo
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy
| | - Gioacchino Natoli
- Department of Experimental Oncology, European Institute of Oncology (IEO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan I-20139, Italy;
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21
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Huang L, Yang H, Chen K, Yuan J, Li J, Dai G, Gu M, Shi Y. The suppressive efficacy of THZ1 depends on KRAS mutation subtype and is associated with super-enhancer activity and the PI3K/AKT/mTOR signalling in pancreatic ductal adenocarcinoma: A hypothesis-generating study. Clin Transl Med 2023; 13:e1500. [PMID: 38037549 PMCID: PMC10689978 DOI: 10.1002/ctm2.1500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 10/24/2023] [Accepted: 11/17/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Inhibition of CDK7, a potent transcription regulator, may bring new hope for treating pancreatic ductal adenocarcinoma (PDAC), which is featured by large genetic heterogeneity and abundant KRAS mutations. This investigation aimed at exploring the discrepant efficacies of THZ1, a small-molecule covalent CDK7 inhibitor, on PDACs with different KRAS mutations and the underlying mechanisms. METHODS Associations of CDK7 expression with survival by KRAS mutations were first assessed. Effects of THZ1 on PDAC by different KRAS mutations were then investigated in vitro and in vivo. Moreover, the effects of THZ1 on gene transcription and phosphorylation of RNA polymerase II (RNAPOLII) in different KRAS mutant PDACs were assessed, and the effect of THZ1 on super-enhancer activity was evaluated using chromatin immunoprecipitation sequencing. Lastly, the effects of THZ1 on the binding of H3K27ac to PIK3CA and on the PI3K/AKT/mTOR signalling were analysed. RESULTS High CDK7 expression was significantly linked to worse survival within PDAC patients carrying KRAS-G12V mutation but not in those with KRAS-G12D mutation. The apoptosis-inducing effect of THZ1 was markedly stronger in KRAS-G12V PDAC than KRAS-G12D cancer. THZ1 significantly inhibited the growth of xenograft tumour with KRAS-G12V mutation, and the inhibition was markedly stronger than for KRAS-G12D tumour. In mini-cell-derived xenograft (CDX) models, THZ1 significantly suppressed KRAS-G12V PDAC but not KRAS-G12D cancer. THZ1 significantly suppressed the phosphorylation of RNAPOLII, and this effect was stronger in KRAS-G12V PDAC (especially at ser5). KRAS-G12V PDAC had more H3K27ac-binding super-enhancers, and the inhibition of THZ1 on super-enhancer activity was also stronger in KRAS-G12V PDAC. Furthermore, THZ1 significantly weakened the binding of H3K27ac to PIK3CA in KRAS-G12V PDAC. THZ1 significantly suppressed the PI3K/AKT/mTOR pathway and its downstream markers, and this effect was stronger in KRAS-G12V cells. CONCLUSIONS In this hypothesis-generating study, THZ1 might selectively inhibit certain PDACs with KRAS-G12V mutation more potently compared with some other PDACs with KRAS-G12D mutation, which might be associated with its effect on super-enhancer activity and the PI3K/AKT/mTOR signalling. Our findings might offer novel key clues for the precise management of PDAC and important evidence for future targeted trial design. HIGHLIGHTS THZ1 had a stronger effect on PDAC-bearing KRAS-G12V mutation than G12D mutation. Suppressive effect of THZ1 on phosphorylation of RNAPOLII was stronger in KRAS-G12V than KRAS-G12D PDAC. Inhibition of THZ1 on super-enhancer activity and H3K27ac binding to PIK3CA was stronger in KRAS-G12V PDAC. Suppressive effect of THZ1 on PI3K/AKT/mTOR pathway was stronger in KRAS-G12V PDAC.
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Affiliation(s)
- Lei Huang
- Department of OncologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Hui Yang
- Department of OncologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Kaidi Chen
- School of Pharmaceutical ScienceZhejiang Chinese Medical UniversityHangzhouChina
| | - Jing Yuan
- Department of PathologyChinese PLA General HospitalBeijingChina
| | - Jie Li
- Department of PathologyChinese PLA General HospitalBeijingChina
| | - Guanghai Dai
- Department of Medical OncologyChinese PLA General HospitalBeijingChina
| | - Mancang Gu
- School of Pharmaceutical ScienceZhejiang Chinese Medical UniversityHangzhouChina
- Academy of Chinese Medical SciencesZhejiang Chinese Medical UniversityHangzhouChina
| | - Yan Shi
- Department of General SurgeryShanghai Seventh People's HospitalShanghai University of Traditional Chinese MedicineShanghaiChina
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22
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Huang J, Ji X. Never a dull enzyme, RNA polymerase II. Transcription 2023; 14:49-67. [PMID: 37132022 PMCID: PMC10353340 DOI: 10.1080/21541264.2023.2208023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/04/2023] Open
Abstract
RNA polymerase II (Pol II) is composed of 12 subunits that collaborate to synthesize mRNA within the nucleus. Pol II is widely recognized as a passive holoenzyme, with the molecular functions of its subunits largely ignored. Recent studies employing auxin-inducible degron (AID) and multi-omics techniques have revealed that the functional diversity of Pol II is achieved through the differential contributions of its subunits to various transcriptional and post-transcriptional processes. By regulating these processes in a coordinated manner through its subunits, Pol II can optimize its activity for diverse biological functions. Here, we review recent progress in understanding Pol II subunits and their dysregulation in diseases, Pol II heterogeneity, Pol II clusters and the regulatory roles of RNA polymerases.
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Affiliation(s)
- Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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23
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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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24
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Keller SH, Deng H, Lim B. Regulation of the dynamic RNA Pol II elongation rate in Drosophila embryos. Cell Rep 2023; 42:113225. [PMID: 37837623 PMCID: PMC10842316 DOI: 10.1016/j.celrep.2023.113225] [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: 06/29/2022] [Revised: 08/20/2023] [Accepted: 09/22/2023] [Indexed: 10/16/2023] Open
Abstract
An increasing number of studies have shown the key role that RNA polymerase II (RNA Pol II) elongation plays in gene regulation. We systematically examine how various enhancers, promoters, and gene body composition influence the RNA Pol II elongation rate through a single-cell-resolution live imaging assay. By using reporter constructs containing 5' MS2 and 3' PP7 repeating stem loops, we quantify the rate of RNA Pol II elongation in live Drosophila embryos. We find that promoters and exonic gene lengths have no effect on elongation rate, while enhancers and the presence of long introns may significantly change how quickly RNA Pol II moves across a gene. Furthermore, we observe in multiple constructs that the RNA Pol II elongation rate accelerates after the transcriptional onset of nuclear cycle 14 in Drosophila embryos. Our study provides a single-cell view of various mechanisms that affect the dynamic RNA Pol II elongation rate, ultimately affecting the rate of mRNA production.
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Affiliation(s)
- Samuel H Keller
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hao Deng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bomyi Lim
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
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25
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Wang C, Chen C, Pan Z, He Y, Zhang Z, Liu R, Xue Y, Zhou Q, Gao X. Quantitative Proteomics of the CDK9 Interactome Reveals a Function of the HSP90-CDC37-P-TEFb Complex for BETi-Induced HIV-1 Latency Reactivation. J Proteome Res 2023; 22:2880-2889. [PMID: 37540094 DOI: 10.1021/acs.jproteome.3c00162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Brd4 has been intensively investigated as a promising drug target because of its implicated functions in oncogenesis, inflammation, and HIV-1 transcription. The formation of the Brd4-P-TEFb (CDK9/Cyclin T1) complex and its regulation of transcriptional elongation are critical for HIV latency reactivation and expression of many oncogenes. To further investigate the mechanism of the Brd4-P-TEFb complex in controlling elongation, mass spectrometry-based quantitative proteomics of the CDK9 interactome was performed. Upon treatment with the selective BET bromodomain inhibitor JQ1, 352 proteins were successfully identified with high confidence as CDK9-interacting proteins. Among them, increased bindings of HSP90 and CDC37 to CDK9 were particularly striking, and our data suggest that the HSP90-CDC37-P-TEFb complex is involved in controlling the dynamic equilibrium of the P-TEFb complex during BETi-induced reactivation of HIV-1 latency. Furthermore, the HSP90-CDC37-P-TEFb complex directly regulates HIV-1 transcription and relies on recruitment by heat shock factor 1 (HSF1) for binding to the HIV-1 promoter. These results advance the understanding of HSP90-CDC37-P-TEFb in HIV-1 latency reversal and enlighten the development of potential strategies to eradicate HIV-1 using a combination of targeted drugs.
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Affiliation(s)
- Cong Wang
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
- Medical Center of Hematology, The Second Affiliated Hospital, Army Medical University, Chongqing 400000, China
| | - Chunjing Chen
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhenrui Pan
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yaohui He
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhanming Zhang
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Rongdiao Liu
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
| | - Yuhua Xue
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Qiang Zhou
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong 999077, China
| | - Xiang Gao
- State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
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26
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Guan Q, Chen Z, Yu F, Liu L, Huang Y, Wei G, Chiang CM, Wong J, Li J. MYC promotes global transcription in part by controlling P-TEFb complex formation via DNA-binding independent inhibition of CDK9 SUMOylation. SCIENCE CHINA. LIFE SCIENCES 2023; 66:2167-2184. [PMID: 37115490 PMCID: PMC10524883 DOI: 10.1007/s11427-022-2281-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/13/2023] [Indexed: 04/29/2023]
Abstract
MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC mutants to dissect the molecular basis for MYC-driven global transcription. We found that MYC mutants deficient in DNA binding or known transcriptional activation activities can still promote global transcription and enhance serine 2 phosphorylation (Ser2P) of the RNA polymerase (Pol) II C-terminal domain (CTD), a hallmark of active elongating RNA Pol II. Two distinct regions within MYC can promote global transcription and Ser2P of Pol II CTD. The ability of various MYC mutants to promote global transcription and Ser2P correlates with their ability to suppress CDK9 SUMOylation and enhance positive transcription elongation factor b (P-TEFb) complex formation. We showed that MYC suppresses CDK9 SUMOylation by inhibiting the interaction between CDK9 and SUMO enzymes including UBC9 and PIAS1. Furthermore, MYC's activity in enhancing global transcription positively contributes to its activity in promoting cell proliferation and transformation. Together, our study demonstrates that MYC promotes global transcription, at least in part, by promoting the formation of the active P-TEFb complex via a sequence-specific DNA-binding activity-independent manner.
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Affiliation(s)
- Qingqing Guan
- Shanghai Key Laboratory of Regulatory Biology, Fengxian District Central Hospital-ECNU Joint Center of Translational Medicine, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Zhaosu Chen
- Shanghai Key Laboratory of Regulatory Biology, Fengxian District Central Hospital-ECNU Joint Center of Translational Medicine, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Fang Yu
- Department of Medicine, UF Health Cancer Center, University of Florida, Gainesville, FL, 32610, USA
| | - Lingling Liu
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yuanyong Huang
- Shanghai Key Laboratory of Regulatory Biology, Fengxian District Central Hospital-ECNU Joint Center of Translational Medicine, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Gang Wei
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Cheng-Ming Chiang
- Simmons Comprehensive Cancer Center, Department of Pharmacology, and Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jiemin Wong
- Shanghai Key Laboratory of Regulatory Biology, Fengxian District Central Hospital-ECNU Joint Center of Translational Medicine, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China.
| | - Jiwen Li
- Shanghai Key Laboratory of Regulatory Biology, Fengxian District Central Hospital-ECNU Joint Center of Translational Medicine, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China.
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27
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Affar M, Bottardi S, Quansah N, Lemarié M, Ramón AC, Affar EB, Milot E. IKAROS: from chromatin organization to transcriptional elongation control. Cell Death Differ 2023:10.1038/s41418-023-01212-2. [PMID: 37620540 DOI: 10.1038/s41418-023-01212-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/26/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023] Open
Abstract
IKAROS is a master regulator of cell fate determination in lymphoid and other hematopoietic cells. This transcription factor orchestrates the association of epigenetic regulators with chromatin, ensuring the expression pattern of target genes in a developmental and lineage-specific manner. Disruption of IKAROS function has been associated with the development of acute lymphocytic leukemia, lymphoma, chronic myeloid leukemia and immune disorders. Paradoxically, while IKAROS has been shown to be a tumor suppressor, it has also been identified as a key therapeutic target in the treatment of various forms of hematological malignancies, including multiple myeloma. Indeed, targeted proteolysis of IKAROS is associated with decreased proliferation and increased death of malignant cells. Although the molecular mechanisms have not been elucidated, the expression levels of IKAROS are variable during hematopoiesis and could therefore be a key determinant in explaining how its absence can have seemingly opposite effects. Mechanistically, IKAROS collaborates with a variety of proteins and complexes controlling chromatin organization at gene regulatory regions, including the Nucleosome Remodeling and Deacetylase complex, and may facilitate transcriptional repression or activation of specific genes. Several transcriptional regulatory functions of IKAROS have been proposed. An emerging mechanism of action involves the ability of IKAROS to promote gene repression or activation through its interaction with the RNA polymerase II machinery, which influences pausing and productive transcription at specific genes. This control appears to be influenced by IKAROS expression levels and isoform production. In here, we summarize the current state of knowledge about the biological roles and mechanisms by which IKAROS regulates gene expression. We highlight the dynamic regulation of this factor by post-translational modifications. Finally, potential avenues to explain how IKAROS destruction may be favorable in the treatment of certain hematological malignancies are also explored.
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Affiliation(s)
- Malik Affar
- Faculty of Medicine, University of Montreal, Montréal, QC, Canada
- Maisonneuve-Rosemont Hospital Research Center, CIUSSS de l'Est-de-l'Île de Montréal, 5415 boulevard de l'Assomption, Montréal, QC, H1T 2M4, Canada
| | - Stefania Bottardi
- Maisonneuve-Rosemont Hospital Research Center, CIUSSS de l'Est-de-l'Île de Montréal, 5415 boulevard de l'Assomption, Montréal, QC, H1T 2M4, Canada
| | - Norreen Quansah
- Maisonneuve-Rosemont Hospital Research Center, CIUSSS de l'Est-de-l'Île de Montréal, 5415 boulevard de l'Assomption, Montréal, QC, H1T 2M4, Canada
| | - Maud Lemarié
- Faculty of Medicine, University of Montreal, Montréal, QC, Canada
- Maisonneuve-Rosemont Hospital Research Center, CIUSSS de l'Est-de-l'Île de Montréal, 5415 boulevard de l'Assomption, Montréal, QC, H1T 2M4, Canada
| | - Ailyn C Ramón
- Faculty of Medicine, University of Montreal, Montréal, QC, Canada
- Maisonneuve-Rosemont Hospital Research Center, CIUSSS de l'Est-de-l'Île de Montréal, 5415 boulevard de l'Assomption, Montréal, QC, H1T 2M4, Canada
| | - El Bachir Affar
- Faculty of Medicine, University of Montreal, Montréal, QC, Canada.
- Maisonneuve-Rosemont Hospital Research Center, CIUSSS de l'Est-de-l'Île de Montréal, 5415 boulevard de l'Assomption, Montréal, QC, H1T 2M4, Canada.
| | - Eric Milot
- Faculty of Medicine, University of Montreal, Montréal, QC, Canada.
- Maisonneuve-Rosemont Hospital Research Center, CIUSSS de l'Est-de-l'Île de Montréal, 5415 boulevard de l'Assomption, Montréal, QC, H1T 2M4, Canada.
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28
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Cho S, Chun Y, He L, Ramirez CB, Ganesh KS, Jeong K, Song J, Cheong JG, Li Z, Choi J, Kim J, Koundouros N, Ding F, Dephoure N, Jang C, Blenis J, Lee G. FAM120A couples SREBP-dependent transcription and splicing of lipogenesis enzymes downstream of mTORC1. Mol Cell 2023; 83:3010-3026.e8. [PMID: 37595559 PMCID: PMC10494788 DOI: 10.1016/j.molcel.2023.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 05/23/2023] [Accepted: 07/15/2023] [Indexed: 08/20/2023]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth that stimulates macromolecule synthesis through transcription, RNA processing, and post-translational modification of metabolic enzymes. However, the mechanisms of how mTORC1 orchestrates multiple steps of gene expression programs remain unclear. Here, we identify family with sequence similarity 120A (FAM120A) as a transcription co-activator that couples transcription and splicing of de novo lipid synthesis enzymes downstream of mTORC1-serine/arginine-rich protein kinase 2 (SRPK2) signaling. The mTORC1-activated SRPK2 phosphorylates splicing factor serine/arginine-rich splicing factor 1 (SRSF1), enhancing its binding to FAM120A. FAM120A directly interacts with a lipogenic transcription factor SREBP1 at active promoters, thereby bridging the newly transcribed lipogenic genes from RNA polymerase II to the SRSF1 and U1-70K-containing RNA-splicing machinery. This mTORC1-regulated, multi-protein complex promotes efficient splicing and stability of lipogenic transcripts, resulting in fatty acid synthesis and cancer cell proliferation. These results elucidate FAM120A as a critical transcription co-factor that connects mTORC1-dependent gene regulation programs for anabolic cell growth.
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Affiliation(s)
- Sungyun Cho
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Yujin Chun
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Long He
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Cuauhtemoc B Ramirez
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, USA; Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Kripa S Ganesh
- Department of Biochemistry, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Kyungjo Jeong
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, South Korea
| | - Junho Song
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, South Korea
| | - Jin Gyu Cheong
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Zhongchi Li
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Jungmin Choi
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, South Korea; Department of Genetics, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Joohwan Kim
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Nikos Koundouros
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, USA; Meyer Cancer Center, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Fangyuan Ding
- Department of Biomedical Engineering, Department of Developmental and Cell Biology, Department of Pharmaceutical Sciences, Center for Synthetic Biology, and Center for Neural Circuit Mapping, University of California Irvine, Irvine, CA, USA; Center for Complex Biological Systems and Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Noah Dephoure
- Meyer Cancer Center, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Cholsoon Jang
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA; Center for Complex Biological Systems and Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA; Center for Epigenetics and Metabolism, University of California Irvine, Irvine, CA, USA
| | - John Blenis
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, USA; Meyer Cancer Center, Weill Cornell Medicine, Cornell University, New York, NY, USA.
| | - Gina Lee
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, USA; Center for Complex Biological Systems and Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA; Center for Epigenetics and Metabolism, University of California Irvine, Irvine, CA, USA.
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29
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Agudo-Ibáñez L, Morante M, García-Gutiérrez L, Quintanilla A, Rodríguez J, Muñoz A, León J, Crespo P. ERK2 stimulates MYC transcription by anchoring CDK9 to the MYC promoter in a kinase activity-independent manner. Sci Signal 2023; 16:eadg4193. [PMID: 37463244 DOI: 10.1126/scisignal.adg4193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 06/28/2023] [Indexed: 07/20/2023]
Abstract
The transcription factor MYC regulates cell proliferation, transformation, and survival in response to growth factor signaling that is mediated in part by the kinase activity of ERK2. Because ERK2 can also bind to DNA to modify gene expression, we investigated whether it more directly regulates MYC transcription. We identified ERK2 binding sites in the MYC promoter and detected ERK2 at the promoter in various serum-stimulated cell types. Expression of nuclear-localized ERK2 constructs in serum-starved cells revealed that ERK2 in the nucleus-regardless of its kinase activity-increased MYC mRNA expression and MYC protein abundance. ERK2 bound to the promoter through its amino-terminal insert domain and to the cyclin-dependent kinase CDK9 (which activates RNA polymerase II) through its carboxyl-terminal conserved docking domain. Both interactions were essential for ERK2-induced MYC expression, and depleting ERK impaired CDK9 occupancy and RNA polymerase II progression at the MYC promoter. Artificially tethering CDK9 to the MYC promoter by fusing it to the ERK2 insert domain was sufficient to stimulate MYC expression in serum-starved cells. Our findings demonstrate a role for ERK2 at the MYC promoter acting as a kinase-independent anchor for the recruitment of CDK9 to promote MYC expression.
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Affiliation(s)
- Lorena Agudo-Ibáñez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander 39011, Spain
| | - Marta Morante
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander 39011, Spain
| | - Lucía García-Gutiérrez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander 39011, Spain
| | - Andrea Quintanilla
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander 39011, Spain
| | - Javier Rodríguez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander 39011, Spain
| | - Alberto Muñoz
- Instituto de Investigaciones Biomédicas "Alberto Sols," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid 28029, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid 2809, Spain
| | - Javier León
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander 39011, Spain
| | - Piero Crespo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander 39011, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid 2809, Spain
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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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31
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Li C, Li Z, Wu Z, Lu H. Phase separation in gene transcription control. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1052-1063. [PMID: 37265348 PMCID: PMC10415188 DOI: 10.3724/abbs.2023099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/28/2023] [Indexed: 06/03/2023] Open
Abstract
Phase separation provides a general mechanism for the formation of biomolecular condensates, and it plays a vital role in regulating diverse cellular processes, including gene expression. Although the role of transcription factors and coactivators in regulating transcription has long been understood, how phase separation is involved in this process is just beginning to be explored. In this review, we highlight recent advance in elucidating the molecular mechanisms and functions of transcriptional condensates in gene expression control. We discuss the different condensates formed at each stage of the transcription cycle and how they are dynamically regulated in response to diverse cellular and extracellular cues that cause rapid changes in gene expression. Furthermore, we present new findings regarding the dysregulation of transcription condensates and their implications in human diseases.
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Affiliation(s)
- Chengyu Li
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell BiologyLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Zhuo Li
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell BiologyLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Zhibing Wu
- Department of OncologyAffiliated Zhejiang HospitalZhejiang University School of MedicineHangzhou310058China
| | - Huasong Lu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell BiologyLife Sciences InstituteZhejiang UniversityHangzhou310058China
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32
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Weiß E, Hennig T, Graßl P, Djakovic L, Whisnant AW, Jürges CS, Koller F, Kluge M, Erhard F, Dölken L, Friedel CC. HSV-1 Infection Induces a Downstream Shift of Promoter-Proximal Pausing for Host Genes. J Virol 2023; 97:e0038123. [PMID: 37093003 PMCID: PMC10231138 DOI: 10.1128/jvi.00381-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 04/03/2023] [Indexed: 04/25/2023] Open
Abstract
Herpes simplex virus 1 (HSV-1) infection exerts a profound shutoff of host gene expression at multiple levels. Recently, HSV-1 infection was reported to also impact promoter-proximal RNA polymerase II (Pol II) pausing, a key step in the eukaryotic transcription cycle, with decreased and increased Pol II pausing observed for activated and repressed genes, respectively. Here, we demonstrate that HSV-1 infection induces more complex alterations in promoter-proximal pausing than previously suspected for the vast majority of cellular genes. While pausing is generally retained, it is shifted to more downstream and less well-positioned sites for most host genes. The downstream shift of Pol II pausing was established between 1.5 and 3 h of infection, remained stable until at least 6 hours postinfection, and was observed in the absence of ICP22. The shift in Pol II pausing does not result from alternative de novo transcription initiation at downstream sites or read-in transcription originating from disruption of transcription termination of upstream genes. The use of downstream secondary pause sites associated with +1 nucleosomes was previously observed upon negative elongation factor (NELF) depletion. However, downstream shifts of Pol II pausing in HSV-1 infection were much more pronounced than observed upon NELF depletion. Thus, our study reveals a novel aspect in which HSV-1 infection fundamentally reshapes host transcriptional processes, providing new insights into the regulation of promoter-proximal Pol II pausing in eukaryotic cells. IMPORTANCE This study provides a genome-wide analysis of changes in promoter-proximal polymerase II (Pol II) pausing on host genes induced by HSV-1 infection. It shows that standard measures of pausing, i.e., pausing indices, do not properly capture the complex and unsuspected alterations in Pol II pausing occurring in HSV-1 infection. Instead of a reduction of pausing with increased elongation, as suggested by pausing index analysis, HSV-1 infection leads to a shift of pausing to downstream and less well-positioned sites than in uninfected cells for the majority of host genes. Thus, HSV-1 infection fundamentally reshapes a key regulatory step at the beginning of the host transcriptional cycle on a genome-wide scale.
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Affiliation(s)
- Elena Weiß
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Hennig
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Pilar Graßl
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lara Djakovic
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Adam W. Whisnant
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Christopher S. Jürges
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Franziska Koller
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Kluge
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Florian Erhard
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Lars Dölken
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Center for Infection Research (HZI), Würzburg, Germany
| | - Caroline C. Friedel
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
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Elsakrmy N, Cui H. R-Loops and R-Loop-Binding Proteins in Cancer Progression and Drug Resistance. Int J Mol Sci 2023; 24:ijms24087064. [PMID: 37108225 PMCID: PMC10138518 DOI: 10.3390/ijms24087064] [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: 02/26/2023] [Revised: 04/06/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
R-loops are three-stranded DNA/RNA hybrids that form by the annealing of the mRNA transcript to its coding template while displacing the non-coding strand. While R-loop formation regulates physiological genomic and mitochondrial transcription and DNA damage response, imbalanced R-loop formation can be a threat to the genomic integrity of the cell. As such, R-loop formation is a double-edged sword in cancer progression, and perturbed R-loop homeostasis is observed across various malignancies. Here, we discuss the interplay between R-loops and tumor suppressors and oncogenes, with a focus on BRCA1/2 and ATR. R-loop imbalances contribute to cancer propagation and the development of chemotherapy drug resistance. We explore how R-loop formation can cause cancer cell death in response to chemotherapeutics and be used to circumvent drug resistance. As R-loop formation is tightly linked to mRNA transcription, their formation is unavoidable in cancer cells and can thus be explored in novel cancer therapeutics.
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Affiliation(s)
- Noha Elsakrmy
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
| | - Haissi Cui
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
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Bitarafan F, Razmara E, Jafarinia E, Almadani N, Garshasbi M. A biallelic variant in POLR2C is associated with congenital hearing loss and male infertility: Case report. Eur J Clin Invest 2023; 53:e13946. [PMID: 36576366 DOI: 10.1111/eci.13946] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 11/28/2022] [Accepted: 12/08/2022] [Indexed: 12/29/2022]
Abstract
BACKGROUND DNA-directed RNA polymerase II subunit 3 (RPB3) is the third largest subunit of RNA polymerase II and is encoded by the POLR2C (OMIM:180663). A large Iranian family with congenital hearing loss and infertility is described here with genetic and clinical characterizations of five male patients. METHODS After doing clinical examinations, the proband was subjected to karyotyping and GJB2/6 sequencing to rule out the most evident chromosomal and gene abnormalities for male infertility and hearing loss, respectively. A custom-designed next-generation sequencing panel was also used to detect mutations in deafness-related genes. Finally, to reveal the underlying molecular cause(s) justifying hearing loss and male infertility, five male patients and 2 healthy male controls within the family were subjected to paired-end whole-exome sequencing (WES). Linkage analysis was also performed based on the data. RESULTS All male patients showed prelingual sensorineural hearing loss and also decreased sperm motility. Linkage analysis determined 16q21 as the most susceptible locus in which a missense variant in exon 7 of POLR2C-NM_032940.3:c.545T>C;p.(Val182Ala)-was identified as a 'likely pathogenic' variant co-segregated with phenotypes. CONCLUSIONS Using segregation and in silico analyses, for the first time, we suggested that the NM_032940.3:c.545T>C; p.(Val182Ala) in POLR2C is associated with hearing loss and male infertility.
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Affiliation(s)
- Fatemeh Bitarafan
- Department of Cellular and Molecular Biology, North Tehran Branch, Islamic Azad University, Tehran, Iran.,Department of Medical Genetics, DeNA Laboratory, Tehran, Iran
| | - Ehsan Razmara
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran
| | - Ehsan Jafarinia
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran
| | - Navid Almadani
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran
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Suzuki H, Furugori K, Abe R, Ogawa S, Ito S, Akiyama T, Horiuchi K, Takahashi H. MED26-containing Mediator may orchestrate multiple transcription processes through organization of nuclear bodies. Bioessays 2023; 45:e2200178. [PMID: 36852638 DOI: 10.1002/bies.202200178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 03/01/2023]
Abstract
Mediator is a coregulatory complex that plays essential roles in multiple processes of transcription regulation. One of the human Mediator subunits, MED26, has a role in recruitment of the super elongation complex (SEC) to polyadenylated genes and little elongation complex (LEC) to non-polyadenylated genes, including small nuclear RNAs (snRNAs) and replication-dependent histone (RDH) genes. MED26-containing Mediator plays a role in 3' Pol II pausing at the proximal region of transcript end sites in RDH genes through recruitment of Cajal bodies (CBs) to histone locus bodies (HLBs). This finding suggests that Mediator is involved in the association of CBs with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing by supplying 3'-end processing factors from CBs. Thus, we argue the possibility that Mediator is involved in the organization of nuclear bodies to orchestrate multiple processes of gene transcription.
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Affiliation(s)
- Hidefumi Suzuki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Kazuki Furugori
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Ryota Abe
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Shintaro Ogawa
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Sayaka Ito
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Tomohiko Akiyama
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Keiko Horiuchi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Hidehisa Takahashi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
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Abstract
Metabolic alterations are a key hallmark of cancer cells, and the augmented synthesis and use of nucleotide triphosphates is a critical and universal metabolic dependency of cancer cells across different cancer types and genetic backgrounds. Many of the aggressive behaviours of cancer cells, including uncontrolled proliferation, chemotherapy resistance, immune evasion and metastasis, rely heavily on augmented nucleotide metabolism. Furthermore, most of the known oncogenic drivers upregulate nucleotide biosynthetic capacity, suggesting that this phenotype is a prerequisite for cancer initiation and progression. Despite the wealth of data demonstrating the efficacy of nucleotide synthesis inhibitors in preclinical cancer models and the well-established clinical use of these drugs in certain cancer settings, the full potential of these agents remains unrealized. In this Review, we discuss recent studies that have generated mechanistic insights into the diverse biological roles of hyperactive cancer cell nucleotide metabolism. We explore opportunities for combination therapies that are highlighted by these recent advances and detail key questions that remain to be answered, with the goal of informing urgently warranted future studies.
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Affiliation(s)
- Nicholas J Mullen
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - Pankaj K Singh
- Department of Oncology Science, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- OU Health Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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37
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Guo C, Zhang Y, Shuai S, Sigbessia A, Hao S, Xie P, Jiang X, Luo Z, Lin C. The super elongation complex (SEC) mediates phase transition of SPT5 during transcriptional pause release. EMBO Rep 2023; 24:e55699. [PMID: 36629390 PMCID: PMC9986819 DOI: 10.15252/embr.202255699] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 01/12/2023] Open
Abstract
Release of promoter-proximally paused RNA Pol II into elongation is a tightly regulated and rate-limiting step in metazoan gene transcription. However, the biophysical mechanism underlying pause release remains unclear. Here, we demonstrate that the pausing and elongation regulator SPT5 undergoes phase transition during transcriptional pause release. SPT5 per se is prone to form clusters. The disordered domain in SPT5 is required for pause release and gene activation. During early elongation, the super elongation complex (SEC) induces SPT5 transition into elongation droplets. Depletion of SEC increases SPT5 pausing clusters. Furthermore, disease-associated SEC mutations impair phase properties of elongation droplets and transcription. Our study suggests that SEC-mediated SPT5 phase transition might be essential for pause release and early elongation and that aberrant phase properties could contribute to transcription abnormality in diseases.
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Affiliation(s)
- Chenghao Guo
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Co‐innovation Center of NeuroregenerationNantong UniversityNantongChina
| | - Yadi Zhang
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Shimin Shuai
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Abire Sigbessia
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Shaohua Hao
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Peng Xie
- Southeast University‐Allen Institute Joint Center, Institute for Brain and IntelligenceSoutheast UniversityNanjingChina
| | - Xu Jiang
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Zhuojuan Luo
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Co‐innovation Center of NeuroregenerationNantong UniversityNantongChina
- Shenzhen Research InstituteSoutheast UniversityShenzhenChina
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Chengqi Lin
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Co‐innovation Center of NeuroregenerationNantong UniversityNantongChina
- Shenzhen Research InstituteSoutheast UniversityShenzhenChina
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Key Laboratory of Technical Evaluation of Fertility Regulation of Non‐human primate, Fujian Provincial Maternity and Children's HospitalAffiliated Hospital of Fujian Medical UniversityFuzhouChina
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Martella N, Pensabene D, Varone M, Colardo M, Petraroia M, Sergio W, La Rosa P, Moreno S, Segatto M. Bromodomain and Extra-Terminal Proteins in Brain Physiology and Pathology: BET-ing on Epigenetic Regulation. Biomedicines 2023; 11:biomedicines11030750. [PMID: 36979729 PMCID: PMC10045827 DOI: 10.3390/biomedicines11030750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
BET proteins function as histone code readers of acetylated lysins that determine the positive regulation in transcription of genes involved in cell cycle progression, differentiation, inflammation, and many other pathways. In recent years, thanks to the development of BET inhibitors, interest in this protein family has risen for its relevance in brain development and function. For example, experimental evidence has shown that BET modulation affects neuronal activity and the expression of genes involved in learning and memory. In addition, BET inhibition strongly suppresses molecular pathways related to neuroinflammation. These observations suggest that BET modulation may play a critical role in the onset and during the development of diverse neurodegenerative and neuropsychiatric disorders, such as Alzheimer’s disease, fragile X syndrome, and Rett syndrome. In this review article, we summarize the most recent evidence regarding the involvement of BET proteins in brain physiology and pathology, as well as their pharmacological potential as targets for therapeutic purposes.
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Affiliation(s)
- Noemi Martella
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
| | - Daniele Pensabene
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
- Department of Science, University Roma Tre, Viale Marconi 446, 00146 Rome, Italy
- Laboratory of Neurodevelopment, Neurogenetics and Neuromolecular Biology, IRCCS Santa Lucia Foundation, 64 via del Fosso di Fiorano, 00179 Rome, Italy
| | - Michela Varone
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
| | - Mayra Colardo
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
| | - Michele Petraroia
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
| | - William Sergio
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
| | - Piergiorgio La Rosa
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, via dei Marsi 78, 00185 Rome, Italy
| | - Sandra Moreno
- Department of Science, University Roma Tre, Viale Marconi 446, 00146 Rome, Italy
- Laboratory of Neurodevelopment, Neurogenetics and Neuromolecular Biology, IRCCS Santa Lucia Foundation, 64 via del Fosso di Fiorano, 00179 Rome, Italy
| | - Marco Segatto
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
- Correspondence:
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Guo Y, Zou Y, Chen Y, Deng D, Zhang Z, Liu K, Tang M, Yang T, Fu S, Zhang C, Si W, Ma Z, Zhang S, Peng B, Xu D, Chen L. Design, synthesis and biological evaluation of purine-based derivatives as novel JAK2/BRD4(BD2) dual target inhibitors. Bioorg Chem 2023; 132:106386. [PMID: 36702002 DOI: 10.1016/j.bioorg.2023.106386] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 01/22/2023]
Abstract
Based on the pharmacological synergy of JAK2 and BRD4 in the NF-κB pathway and positive therapeutic effect of combination of JAK2 and BRD4 inhibitors in treating MPN and inflammation. A series of unique 9H-purine-2,6-diamine derivatives that selectively inhibited Janus kinase 2 (JAK2) and BRD4(BD2) were designed, prepared, and evaluated for their in vitro and in vivo potency. Among them, compound 9j exhibited acceptable inhibitory activity with IC50 values of 13 and 22 nM for BD2 of BRD4 and JAK2, respectively. The western blot assay demonstrated that 9j performed good functional potency in the NF-κB pathway and the phosphorylation of p65, IκB-α, and IKKα/β signal intensities were suppressed on RAW264.7 cell lines. Furthermore, 9j significantly improved the disease symptoms in a Ba/F3-JAK2V617F allograft model. Meanwhile, 9j was also effective in relieving symptoms in an acute ulcerative colitis model. Taken together, 9j was a potent JAK2/BRD4(BD2) dual target inhibitor and could be a potential lead compound in treating myeloproliferative neoplasms and inflammatory diseases.
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Affiliation(s)
- Yong Guo
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yurong Zou
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Yong Chen
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Dexin Deng
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zihao Zhang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Kongjun Liu
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Minghai Tang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Tao Yang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Suhong Fu
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chufeng Zhang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Wenting Si
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Ziyan Ma
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shunjie Zhang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Bin Peng
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Dingguo Xu
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Lijuan Chen
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.
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40
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Guo J, Zheng Q, Peng Y. BET proteins: Biological functions and therapeutic interventions. Pharmacol Ther 2023; 243:108354. [PMID: 36739915 DOI: 10.1016/j.pharmthera.2023.108354] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/29/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
Bromodomain and extra-terminal (BET) family member proteins (BRD2, BRD3, BRD4 and BRDT) play a pivotal role in interpreting the epigenetic information of histone Kac modification, thus controlling gene expression, remodeling chromatin structures and avoid replicative stress-induced DNA damages. Abnormal activation of BET proteins is tightly correlated to various human diseases, including cancer. Therefore, BET bromodomain inhibitors (BBIs) were considered as promising therapeutics to treat BET-related diseases, raising >70 clinical trials in the past decades. Despite preliminary effects achieved, drug resistance and adverse events represent two major challenges for current BBIs development. In this review, we will introduce the biological functions of BET proteins in both physiological and pathological conditions; and summarize the progress in current BBI drug development. Moreover, we will also discuss the major challenges in the front of BET inhibitor development and provide rational strategies to overcome these obstacles.
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Affiliation(s)
- Jiawei Guo
- Laboratory of Molecular Oncology, Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qingquan Zheng
- Laboratory of Molecular Oncology, Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yong Peng
- Laboratory of Molecular Oncology, Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; Frontier Medical Center, Tianfu Jincheng Laboratory, Chengdu, 610212, China.
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41
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Wang Z, Mačáková M, Bugai A, Kuznetsov SG, Hassinen A, Lenasi T, Potdar S, Friedel CC, Barborič M. P-TEFb promotes cell survival upon p53 activation by suppressing intrinsic apoptosis pathway. Nucleic Acids Res 2023; 51:1687-1706. [PMID: 36727434 PMCID: PMC9976905 DOI: 10.1093/nar/gkad001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/27/2022] [Accepted: 01/03/2023] [Indexed: 02/03/2023] Open
Abstract
Positive transcription elongation factor b (P-TEFb) is the crucial player in RNA polymerase II (Pol II) pause release that has emerged as a promising target in cancer. Because single-agent therapy may fail to deliver durable clinical response, targeting of P-TEFb shall benefit when deployed as a combination therapy. We screened a comprehensive oncology library and identified clinically relevant antimetabolites and Mouse double minute 2 homolog (MDM2) inhibitors as top compounds eliciting p53-dependent death of colorectal cancer cells in synergy with selective inhibitors of P-TEFb. While the targeting of P-TEFb augments apoptosis by anti-metabolite 5-fluorouracil, it switches the fate of cancer cells by the non-genotoxic MDM2 inhibitor Nutlin-3a from cell-cycle arrest to apoptosis. Mechanistically, the fate switching is enabled by the induction of p53-dependent pro-apoptotic genes and repression of P-TEFb-dependent pro-survival genes of the PI3K-AKT signaling cascade, which stimulates caspase 9 and intrinsic apoptosis pathway in BAX/BAK-dependent manner. Finally, combination treatments trigger apoptosis of cancer cell spheroids. Together, co-targeting of P-TEFb and suppressors of intrinsic apoptosis could become a viable strategy to eliminate cancer cells.
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Affiliation(s)
- Zhijia Wang
- Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Monika Mačáková
- Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Andrii Bugai
- Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland.,Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Sergey G Kuznetsov
- High-Throughput Biomedicine Unit (HTB), Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FIN-00014, Finland
| | - Antti Hassinen
- High Content Imaging and Analysis Unit (HCA), Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FIN-00014, Finland
| | - Tina Lenasi
- Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Swapnil Potdar
- High-Throughput Biomedicine Unit (HTB), Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FIN-00014, Finland
| | - Caroline C Friedel
- Institute for Informatics, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - Matjaž Barborič
- Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
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42
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Khan SM, Martin RD, Bayne A, Pétrin D, Bourque K, Jones-Tabah J, Bouazza C, Blaney J, Lau J, Martins-Cannavino K, Gora S, Zhang A, MacKinnon S, Trieu P, Clarke PBS, Trempe JF, Tanny JC, Hébert TE. Gβγ subunits colocalize with RNA polymerase II and regulate transcription in cardiac fibroblasts. J Biol Chem 2023; 299:103064. [PMID: 36841480 PMCID: PMC10060754 DOI: 10.1016/j.jbc.2023.103064] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/26/2023] Open
Abstract
Gβγ subunits mediate many different signaling processes in various compartments of the cell, including the nucleus. To gain insight into the functions of nuclear Gβγ signaling, we investigated the functional role of Gβγ signaling in the regulation of GPCR-mediated gene expression in primary rat neonatal cardiac fibroblasts. We identified a novel, negative, regulatory role for the Gβ1γ dimer in the fibrotic response. Depletion of Gβ1 led to derepression of the fibrotic response at the mRNA and protein levels under basal conditions and an enhanced fibrotic response after sustained stimulation of the angiotensin II type I receptor. Our genome-wide chromatin immunoprecipitation experiments revealed that Gβ1 colocalized and interacted with RNA polymerase II on fibrotic genes in an angiotensin II-dependent manner. Additionally, blocking transcription with inhibitors of Cdk9 prevented association of Gβγ with transcription complexes. Together, our findings suggest that Gβ1γ is a novel transcriptional regulator of the fibrotic response that may act to restrict fibrosis to conditions of sustained fibrotic signaling. Our work expands the role for Gβγ signaling in cardiac fibrosis and may have broad implications for the role of nuclear Gβγ signaling in other cell types.
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Affiliation(s)
- Shahriar M Khan
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Andrew Bayne
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec, Canada
| | - Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Kyla Bourque
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jace Jones-Tabah
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Celia Bouazza
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jacob Blaney
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jenny Lau
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | | | - Sarah Gora
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Andy Zhang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Sarah MacKinnon
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Phan Trieu
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Paul B S Clarke
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jean-François Trempe
- Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec, Canada
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
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43
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Zhuang HH, Qu Q, Teng XQ, Dai YH, Qu J. Superenhancers as master gene regulators and novel therapeutic targets in brain tumors. Exp Mol Med 2023; 55:290-303. [PMID: 36720920 PMCID: PMC9981748 DOI: 10.1038/s12276-023-00934-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 11/27/2022] [Accepted: 12/04/2022] [Indexed: 02/02/2023] Open
Abstract
Transcriptional deregulation, a cancer cell hallmark, is driven by epigenetic abnormalities in the majority of brain tumors, including adult glioblastoma and pediatric brain tumors. Epigenetic abnormalities can activate epigenetic regulatory elements to regulate the expression of oncogenes. Superenhancers (SEs), identified as novel epigenetic regulatory elements, are clusters of enhancers with cell-type specificity that can drive the aberrant transcription of oncogenes and promote tumor initiation and progression. As gene regulators, SEs are involved in tumorigenesis in a variety of tumors, including brain tumors. SEs are susceptible to inhibition by their key components, such as bromodomain protein 4 and cyclin-dependent kinase 7, providing new opportunities for antitumor therapy. In this review, we summarized the characteristics and identification, unique organizational structures, and activation mechanisms of SEs in tumors, as well as the clinical applications related to SEs in tumor therapy and prognostication. Based on a review of the literature, we discussed the relationship between SEs and different brain tumors and potential therapeutic targets, focusing on glioblastoma.
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Affiliation(s)
- Hai-Hui Zhuang
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Institute of Clinical Pharmacy, Central South University, Changsha, 410011, PR China
| | - Qiang Qu
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, 410007, PR China.,Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410007, PR China
| | - Xin-Qi Teng
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Institute of Clinical Pharmacy, Central South University, Changsha, 410011, PR China
| | - Ying-Huan Dai
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, 410011, PR China
| | - Jian Qu
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Institute of Clinical Pharmacy, Central South University, Changsha, 410011, PR China.
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44
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Walker FM, Sobral LM, Danis E, Sanford B, Balakrishnan I, Wang D, Pierce A, Karam SD, Serkova NJ, Foreman NK, Venkataraman S, Dowell R, Vibhakar R, Dahl NA. Rapid PTEFb-dependent transcriptional reorganization underpins the glioma adaptive response to radiotherapy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.24.525424. [PMID: 36747867 PMCID: PMC9900817 DOI: 10.1101/2023.01.24.525424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Dynamic regulation of gene expression is fundamental for cellular adaptation to exogenous stressors. PTEFb-mediated pause-release of RNA polymerase II (Pol II) is a conserved regulatory mechanism for synchronous transcriptional induction in response to heat shock, but this pro-survival role has not been examined in the applied context of cancer therapy. Using model systems of pediatric high-grade glioma, we show that rapid genome-wide reorganization of active chromatin facilitates PTEFb-mediated nascent transcriptional induction within hours of exposure to therapeutic ionizing radiation. Concurrent inhibition of PTEFb disrupts this chromatin reorganization and blunts transcriptional induction, abrogating key adaptive programs such as DNA damage repair and cell cycle regulation. This combination demonstrates a potent, synergistic therapeutic potential agnostic of glioma subtype, leading to a marked induction of tumor cell apoptosis and prolongation of xenograft survival. These studies reveal a central role for PTEFb underpinning the early adaptive response to radiotherapy, opening new avenues for combinatorial treatment in these lethal malignancies.
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45
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Wu X, Xie Y, Zhao K, Lu J. Targeting the super elongation complex for oncogenic transcription driven tumor malignancies: Progress in structure, mechanisms and small molecular inhibitor discovery. Adv Cancer Res 2023; 158:387-421. [PMID: 36990537 DOI: 10.1016/bs.acr.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Oncogenic transcription activation is associated with tumor development and resistance derived from chemotherapy or target therapy. The super elongation complex (SEC) is an important complex regulating gene transcription and expression in metazoans closely related to physiological activities. In normal transcriptional regulation, SEC can trigger promoter escape, limit proteolytic degradation of transcription elongation factors and increase the synthesis of RNA polymerase II (POL II), and regulate many normal human genes to stimulate RNA elongation. Dysregulation of SEC accompanied by multiple transcription factors in cancer promotes rapid transcription of oncogenes and induce cancer development. In this review, we summarized recent progress in understanding the mechanisms of SEC in regulating normal transcription, and importantly its roles in cancer development. We also highlighted the discovery of SEC complex target related inhibitors and their potential applications in cancer treatment.
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Affiliation(s)
- Xinyu Wu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China; Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yanqiu Xie
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China; Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Kehao Zhao
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China.
| | - Jing Lu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China.
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46
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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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47
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Skouras P, Markouli M, Strepkos D, Piperi C. Advances on Epigenetic Drugs for Pediatric Brain Tumors. Curr Neuropharmacol 2023; 21:1519-1535. [PMID: 36154607 PMCID: PMC10472812 DOI: 10.2174/1570159x20666220922150456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/14/2022] [Accepted: 09/08/2022] [Indexed: 11/22/2022] Open
Abstract
Pediatric malignant brain tumors represent the most frequent cause of cancer-related deaths in childhood. The therapeutic scheme of surgery, radiotherapy and chemotherapy has improved patient management, but with minimal progress in patients' prognosis. Emerging molecular targets and mechanisms have revealed novel approaches for pediatric brain tumor therapy, enabling personalized medical treatment. Advances in the field of epigenetic research and their interplay with genetic changes have enriched our knowledge of the molecular heterogeneity of these neoplasms and have revealed important genes that affect crucial signaling pathways involved in tumor progression. The great potential of epigenetic therapy lies mainly in the widespread location and the reversibility of epigenetic alterations, proposing a wide range of targeting options, including the possible combination of chemoand immunotherapy, significantly increasing their efficacy. Epigenetic drugs, including inhibitors of DNA methyltransferases, histone deacetylases and demethylases, are currently being tested in clinical trials on pediatric brain tumors. Additional novel epigenetic drugs include protein and enzyme inhibitors that modulate epigenetic modification pathways, such as Bromodomain and Extraterminal (BET) proteins, Cyclin-Dependent Kinase 9 (CDK9), AXL, Facilitates Chromatin Transcription (FACT), BMI1, and CREB Binding Protein (CBP) inhibitors, which can be used either as standalone or in combination with current treatment approaches. In this review, we discuss recent progress on epigenetic drugs that could possibly be used against the most common malignant tumors of childhood, such as medulloblastomas, high-grade gliomas and ependymomas.
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Affiliation(s)
- Panagiotis Skouras
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Mariam Markouli
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Dimitrios Strepkos
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
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48
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Sharma AL, Shaffer D, Netting D, Tyagi M. Cocaine sensitizes the CD4 + T cells for HIV infection by co-stimulating NFAT and AP-1. iScience 2022; 25:105651. [PMID: 36483012 PMCID: PMC9722482 DOI: 10.1016/j.isci.2022.105651] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/28/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
The productive infection of HIV, which generates new viral progeny, depends on the activation status of the cell. In this study, we found cocaine exposure sensitizes partially active CD4+ T cells and makes them poised for productive HIV infection. We discovered that cocaine treatment enhances the metabolic state of the cells by co-stimulating several transcription factors, mainly NFAT and AP-1, the two transcription factors, which specifically play a crucial role in enhancing both HIV and the overall cellular gene expression in T cells. We found that cocaine-induced AP-1 works in tandem with NFAT to boost HIV transcription. The enhanced HIV transcription upon cocaine exposure was further confirmed through higher phosphorylation of the crucial serine residues at the carboxyl-terminal domain (CTD) of RNA polymerase II. The insights gained from this study could aid in developing highly specialized therapeutics combating the deleterious effects of cocaine on the cocaine-using HIV population.
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Affiliation(s)
| | - Dylan Shaffer
- Center for Translational Medicine, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Daniel Netting
- Center for Translational Medicine, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Mudit Tyagi
- Center for Translational Medicine, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
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49
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Lu H, Yang M, Zhou Q. Reprogramming transcription after DNA damage: recognition, response, repair, and restart. Trends Cell Biol 2022:S0962-8924(22)00261-6. [PMID: 36513571 DOI: 10.1016/j.tcb.2022.11.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/20/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022]
Abstract
Genome integrity is constantly challenged by endogenous and exogenous insults that cause DNA damage. To cope with these threats, cells have a surveillance mechanism, known as the DNA damage response (DDR), to repair any lesions. Although transcription has long been implicated in DNA repair, how transcriptional reprogramming is coordinated with the DDR is just beginning to be understood. In this review, we highlight recent advances in elucidating the molecular mechanisms underlying major transcriptional events, including RNA polymerase (Pol) II stalling and transcriptional silencing and recovery, which occur in response to DNA damage. Furthermore, we discuss how such transcriptional adaptation contributes to sensing and eliminating damaged DNA and how it can jeopardize genome integrity when it goes awry.
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Affiliation(s)
- Huasong Lu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China.
| | - Min Yang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Qiang Zhou
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong.
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50
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Huffines AK, Engel KL, French SL, Zhang Y, Viktorovskaya OV, Schneider DA. Rate of transcription elongation and sequence-specific pausing by RNA polymerase I directly influence rRNA processing. J Biol Chem 2022; 298:102730. [PMID: 36423683 PMCID: PMC9768379 DOI: 10.1016/j.jbc.2022.102730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/18/2022] [Accepted: 11/07/2022] [Indexed: 11/23/2022] Open
Abstract
One of the first steps in ribosome biogenesis is transcription of the ribosomal DNA by RNA polymerase I (Pol I). Processing of the resultant rRNA begins cotranscriptionally, and perturbation of Pol I transcription elongation results in defective rRNA processing. Mechanistic insight regarding the link between transcription elongation and ribosome assembly is lacking because of limited in vivo methods to assay Pol I transcription. Here, we use native elongating transcript sequencing (NET-Seq) with a strain of Saccharomyces cerevisiae containing a point mutation in Pol I, rpa190-F1205H, which results in impaired rRNA processing and ribosome assembly. We previously demonstrated that this mutation caused a mild reduction in the transcription elongation rate of Pol I in vitro; however, transcription elongation by the mutant has not been characterized in vivo. Here, our findings demonstrate that the mutant Pol I has an increased pause propensity during processive transcription elongation both in vitro and in vivo. NET-Seq reveals that rpa190-F1205H Pol I displays alternative pause site preferences in vivo. Specifically, the mutant is sensitized to A/G residues in the RNA:DNA hybrid and at the last incorporated nucleotide position. Furthermore, both NET-Seq and EM analysis of Miller chromatin spreads reveal pileups of rpa190-F1205H Pol I throughout the ribosomal DNA, particularly at the 5' end of the 35S gene. This combination of in vitro and in vivo analyses of a Pol I mutant provides novel insights into Pol I elongation properties and indicates how these properties are crucial for efficient cotranscriptional rRNA processing and ribosome assembly.
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Affiliation(s)
- Abigail K Huffines
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Krysta L Engel
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Sarah L French
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Yinfeng Zhang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Olga V Viktorovskaya
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David A Schneider
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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