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D'Orso I. The HIV-1 Transcriptional Program: From Initiation to Elongation Control. J Mol Biol 2024:168690. [PMID: 38936695 DOI: 10.1016/j.jmb.2024.168690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/29/2024]
Abstract
A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
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Affiliation(s)
- Iván D'Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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2
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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] [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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3
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Yang Y, Ahmad E, Premkumar V, Liu A, Ashikur Rahman SM, Nikolovska‐Coleska Z. Structural studies of intrinsically disordered MLL-fusion protein AF9 in complex with peptidomimetic inhibitors. Protein Sci 2024; 33:e5019. [PMID: 38747396 PMCID: PMC11094776 DOI: 10.1002/pro.5019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 04/23/2024] [Accepted: 04/28/2024] [Indexed: 05/19/2024]
Abstract
AF9 (MLLT3) and its paralog ENL(MLLT1) are members of the YEATS family of proteins with important role in transcriptional and epigenetic regulatory complexes. These proteins are two common MLL fusion partners in MLL-rearranged leukemias. The oncofusion proteins MLL-AF9/ENL recruit multiple binding partners, including the histone methyltransferase DOT1L, leading to aberrant transcriptional activation and enhancing the expression of a characteristic set of genes that drive leukemogenesis. The interaction between AF9 and DOT1L is mediated by an intrinsically disordered C-terminal ANC1 homology domain (AHD) in AF9, which undergoes folding upon binding of DOT1L and other partner proteins. We have recently reported peptidomimetics that disrupt the recruitment of DOT1L by AF9 and ENL, providing a proof-of-concept for targeting AHD and assessing its druggability. Intrinsically disordered proteins, such as AF9 AHD, are difficult to study and characterize experimentally on a structural level. In this study, we present a successful protein engineering strategy to facilitate structural investigation of the intrinsically disordered AF9 AHD domain in complex with peptidomimetic inhibitors by using maltose binding protein (MBP) as a crystallization chaperone connected with linkers of varying flexibility and length. The strategic incorporation of disulfide bonds provided diffraction-quality crystals of the two disulfide-bridged MBP-AF9 AHD fusion proteins in complex with the peptidomimetics. These successfully determined first series of 2.1-2.6 Å crystal complex structures provide high-resolution insights into the interactions between AHD and its inhibitors, shedding light on the role of AHD in recruiting various binding partner proteins. We show that the overall complex structures closely resemble the reported NMR structure of AF9 AHD/DOT1L with notable difference in the conformation of the β-hairpin region, stabilized through conserved hydrogen bonds network. These first series of AF9 AHD/peptidomimetics complex structures are providing insights of the protein-inhibitor interactions and will facilitate further development of novel inhibitors targeting the AF9/ENL AHD domain.
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Affiliation(s)
- Yuting Yang
- Department of PathologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Ejaz Ahmad
- Department of PathologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Vidhya Premkumar
- Department of PathologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Alicen Liu
- Department of PathologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - S. M. Ashikur Rahman
- Department of PathologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Zaneta Nikolovska‐Coleska
- Department of PathologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
- Rogel Cancer CenterUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
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4
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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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5
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Boddu PC, Gupta AK, Roy R, De La Peña Avalos B, Olazabal-Herrero A, Neuenkirchen N, Zimmer JT, Chandhok NS, King D, Nannya Y, Ogawa S, Lin H, Simon MD, Dray E, Kupfer GM, Verma A, Neugebauer KM, Pillai MM. Transcription elongation defects link oncogenic SF3B1 mutations to targetable alterations in chromatin landscape. Mol Cell 2024; 84:1475-1495.e18. [PMID: 38521065 PMCID: PMC11061666 DOI: 10.1016/j.molcel.2024.02.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 11/26/2023] [Accepted: 02/27/2024] [Indexed: 03/25/2024]
Abstract
Transcription and splicing of pre-messenger RNA are closely coordinated, but how this functional coupling is disrupted in human diseases remains unexplored. Using isogenic cell lines, patient samples, and a mutant mouse model, we investigated how cancer-associated mutations in SF3B1 alter transcription. We found that these mutations reduce the elongation rate of RNA polymerase II (RNAPII) along gene bodies and its density at promoters. The elongation defect results from disrupted pre-spliceosome assembly due to impaired protein-protein interactions of mutant SF3B1. The decreased promoter-proximal RNAPII density reduces both chromatin accessibility and H3K4me3 marks at promoters. Through an unbiased screen, we identified epigenetic factors in the Sin3/HDAC/H3K4me pathway, which, when modulated, reverse both transcription and chromatin changes. Our findings reveal how splicing factor mutant states behave functionally as epigenetic disorders through impaired transcription-related changes to the chromatin landscape. We also present a rationale for targeting the Sin3/HDAC complex as a therapeutic strategy.
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Affiliation(s)
- Prajwal C Boddu
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Abhishek K Gupta
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Rahul Roy
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Bárbara De La Peña Avalos
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center (UTHSC) at San Antonio, San Antonio, TX, USA
| | - Anne Olazabal-Herrero
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA
| | - Nils Neuenkirchen
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA; Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT, USA
| | - Joshua T Zimmer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Namrata S Chandhok
- Division of Hematology, Department of Medicine, Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL, USA
| | - Darren King
- Section of Hematology and Medical Oncology, Department of Internal Medicine and Rogel Cancer Center, University of Michigan Health, Ann Arbor, MI, USA
| | - Yasuhito Nannya
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Haifan Lin
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA; Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT, USA
| | - Matthew D Simon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Eloise Dray
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center (UTHSC) at San Antonio, San Antonio, TX, USA
| | - Gary M Kupfer
- Department of Oncology and Pediatrics, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
| | - Amit Verma
- Division of Hemato-Oncology, Department of Medicine and Department of Developmental and Molecular Biology, Albert Einstein-Montefiore Cancer Center, New York, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Yale Center for RNA Science and Medicine, Yale University, New Haven, CT, USA
| | - Manoj M Pillai
- Section of Hematology, Yale Cancer Center and Department of Internal Medicine, Yale University School of Medicine, 300 George Street, Suite 786, New Haven, CT 06511, USA; Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT, USA; Yale Center for RNA Science and Medicine, Yale University, New Haven, CT, USA; Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.
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6
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Chen Y, Ying Y, Ma W, Ma H, Shi L, Gao X, Jia M, Li M, Song X, Kong W, Chen W, Zheng X, Muluh TA, Wang X, Wang M, Shu XS. Targeting the Epigenetic Reader ENL Inhibits Super-Enhancer-Driven Oncogenic Transcription and Synergizes with BET Inhibition to Suppress Tumor Progression. Cancer Res 2024; 84:1237-1251. [PMID: 38241700 DOI: 10.1158/0008-5472.can-23-1836] [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: 06/20/2023] [Revised: 11/23/2023] [Accepted: 01/18/2024] [Indexed: 01/21/2024]
Abstract
Epigenetic alterations at cis-regulatory elements (CRE) fine-tune transcriptional output. Epigenetic readers interact with CREs and can cooperate with other chromatin regulators to drive oncogene transcription. Here, we found that the YEATS domain-containing histone acetylation reader ENL (eleven-nineteen leukemia) acts as a key regulator of super-enhancers (SE), which are highly active distal CREs, across cancer types. ENL occupied the majority of SEs with substantially higher preference over typical enhancers, and the enrichment of ENL at SEs depended on its ability to bind acetylated histones. Rapid depletion of ENL by auxin-inducible degron tagging severely repressed the transcription of SE-controlled oncogenes, such as MYC, by inducing the decommissioning of their SEs, and restoring ENL protein expression largely reversed these effects. Additionally, ENL was indispensable for the rapid activation of SE-regulated immediate early genes in response to growth factor stimulation. Furthermore, ENL interacted with the histone chaperone FACT complex and was required for the deposition of FACT over CREs, which mediates nucleosome reorganization required for transcription initiation and elongation. Proper control of transcription by ENL and ENL-associated FACT was regulated by the histone reader BRD4. ENL was overexpressed in colorectal cancer and functionally contributed to colorectal cancer growth and metastasis. ENL degradation or inhibition synergized with BET inhibitors that target BRD4 in restraining colorectal cancer progression. These findings establish the essential role of epigenetic reader ENL in governing SE-driven oncogenic transcription and uncover the potential of ENL intervention to increase sensitivity to BET inhibition. SIGNIFICANCE ENL plays a key role in decoding epigenetic marks at highly active oncogenic super-enhancers and can be targeted in combination with BET inhibition as a promising synergistic strategy for optimizing cancer treatment.
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Affiliation(s)
- Yongheng Chen
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
- Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, China
- Graduate Program of Pharmaceutical Sciences, Shenzhen University Medical School, Shenzhen, China
| | - Ying Ying
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Wenlong Ma
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Hongchao Ma
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Liang Shi
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Xuefeng Gao
- Integrative Microecology Center, Department of Gastroenterology, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Min Jia
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Meiqi Li
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Xiaoman Song
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Weixiao Kong
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Wei Chen
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
- Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, China
| | - Xiangyi Zheng
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Tobias Achu Muluh
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
| | - Xiaobin Wang
- Southern University of Science and Technology Hospital, Shenzhen, China
| | - Maolin Wang
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
- Clinical Research Center, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Xing-Sheng Shu
- Department of Physiology, Shenzhen University Medical School, Shenzhen, China
- Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, China
- Graduate Program of Pharmaceutical Sciences, Shenzhen University Medical School, Shenzhen, China
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Bottardi S, Layne T, Ramòn AC, Quansah N, Wurtele H, Affar EB, Milot E. MNDA, a PYHIN factor involved in transcriptional regulation and apoptosis control in leukocytes. Front Immunol 2024; 15:1395035. [PMID: 38680493 PMCID: PMC11045911 DOI: 10.3389/fimmu.2024.1395035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Accepted: 04/02/2024] [Indexed: 05/01/2024] Open
Abstract
Inflammation control is critical during the innate immune response. Such response is triggered by the detection of molecules originating from pathogens or damaged host cells by pattern-recognition receptors (PRRs). PRRs subsequently initiate intra-cellular signalling through different pathways, resulting in i) the production of inflammatory cytokines, including type I interferon (IFN), and ii) the initiation of a cascade of events that promote both immediate host responses as well as adaptive immune responses. All human PYRIN and HIN-200 domains (PYHIN) protein family members were initially proposed to be PRRs, although this view has been challenged by reports that revealed their impact on other cellular mechanisms. Of relevance here, the human PYHIN factor myeloid nuclear differentiation antigen (MNDA) has recently been shown to directly control the transcription of genes encoding factors that regulate programmed cell death and inflammation. While MNDA is mainly found in the nucleus of leukocytes of both myeloid (neutrophils and monocytes) and lymphoid (B-cell) origin, its subcellular localization has been shown to be modulated in response to genotoxic agents that induce apoptosis and by bacterial constituents, mediators of inflammation. Prior studies have noted the importance of MNDA as a marker for certain forms of lymphoma, and as a clinical prognostic factor for hematopoietic diseases characterized by defective regulation of apoptosis. Abnormal expression of MNDA has also been associated with altered levels of cytokines and other inflammatory mediators. Refining our comprehension of the regulatory mechanisms governing the expression of MNDA and other PYHIN proteins, as well as enhancing our definition of their molecular functions, could significantly influence the management and treatment strategies of numerous human diseases. Here, we review the current state of knowledge regarding PYHIN proteins and their role in innate and adaptive immune responses. Emphasis will be placed on the regulation, function, and relevance of MNDA expression in the control of gene transcription and RNA stability during cell death and inflammation.
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Affiliation(s)
- Stefania Bottardi
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l’Est-de-l’Île de Montreal, Montreal, QC, Canada
| | - Taylorjade Layne
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l’Est-de-l’Île de Montreal, Montreal, QC, Canada
| | - Ailyn C. Ramòn
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l’Est-de-l’Île de Montreal, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Norreen Quansah
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l’Est-de-l’Île de Montreal, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Hugo Wurtele
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l’Est-de-l’Île de Montreal, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - El Bachir Affar
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l’Est-de-l’Île de Montreal, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Eric Milot
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l’Est-de-l’Île de Montreal, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
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Soliman SHA, Iwanaszko M, Zheng B, Gold S, Howard BC, Das M, Chakrabarty RP, Chandel NS, Shilatifard A. Transcriptional elongation control of hypoxic response. Proc Natl Acad Sci U S A 2024; 121:e2321502121. [PMID: 38564636 PMCID: PMC11009653 DOI: 10.1073/pnas.2321502121] [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: 12/06/2023] [Accepted: 02/23/2024] [Indexed: 04/04/2024] Open
Abstract
The release of paused RNA polymerase II (RNAPII) from promoter-proximal regions is tightly controlled to ensure proper regulation of gene expression. The elongation factor PTEF-b is known to release paused RNAPII via phosphorylation of the RNAPII C-terminal domain by its cyclin-dependent kinase component, CDK9. However, the signal and stress-specific roles of the various RNAPII-associated macromolecular complexes containing PTEF-b/CDK9 are not yet clear. Here, we identify and characterize the CDK9 complex required for transcriptional response to hypoxia. Contrary to previous reports, our data indicate that a CDK9 complex containing BRD4 but not AFF1/4 is essential for this hypoxic stress response. We demonstrate that BRD4 bromodomains (BET) are dispensable for the release of paused RNAPII at hypoxia-activated genes and that BET inhibition by JQ1 is insufficient to impair hypoxic gene response. Mechanistically, we demonstrate that the C-terminal region of BRD4 is required for Polymerase-Associated Factor-1 Complex (PAF1C) recruitment to establish an elongation-competent RNAPII complex at hypoxia-responsive genes. PAF1C disruption using a small-molecule inhibitor (iPAF1C) impairs hypoxia-induced, BRD4-mediated RNAPII release. Together, our results provide insight into potentially targetable mechanisms that control the hypoxia-responsive transcriptional elongation.
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Affiliation(s)
- Shimaa Hassan AbdelAziz Soliman
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Marta Iwanaszko
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Bin Zheng
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Sarah Gold
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Benjamin Charles Howard
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Madhurima Das
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Ram Prosad Chakrabarty
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
- Division of Pulmonary and Critical Care, Department of Medicine, Northwestern University, Chicago, IL60611
| | - Navdeep S. Chandel
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
- Division of Pulmonary and Critical Care, Department of Medicine, Northwestern University, Chicago, IL60611
| | - Ali Shilatifard
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
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9
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Kuzmina A, Sadhu L, Hasanuzzaman M, Fujinaga K, Schwartz JC, Fackler OT, Taube R. Direct and indirect effects of CYTOR lncRNA regulate HIV gene expression. PLoS Pathog 2024; 20:e1012172. [PMID: 38662769 PMCID: PMC11075828 DOI: 10.1371/journal.ppat.1012172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 05/07/2024] [Accepted: 04/05/2024] [Indexed: 05/08/2024] Open
Abstract
The implementation of antiretroviral therapy (ART) has effectively restricted the transmission of Human Immunodeficiency Virus (HIV) and improved overall clinical outcomes. However, a complete cure for HIV remains out of reach, as the virus persists in a stable pool of infected cell reservoir that is resistant to therapy and thus a main barrier towards complete elimination of viral infection. While the mechanisms by which host proteins govern viral gene expression and latency are well-studied, the emerging regulatory functions of non-coding RNAs (ncRNA) in the context of T cell activation, HIV gene expression and viral latency have not yet been thoroughly explored. Here, we report the identification of the Cytoskeleton Regulator (CYTOR) long non-coding RNA (lncRNA) as an activator of HIV gene expression that is upregulated following T cell stimulation. Functional studies show that CYTOR suppresses viral latency by directly binding to the HIV promoter and associating with the cellular positive transcription elongation factor (P-TEFb) to activate viral gene expression. CYTOR also plays a global role in regulating cellular gene expression, including those involved in controlling actin dynamics. Depletion of CYTOR expression reduces cytoplasmic actin polymerization in response to T cell activation. In addition, treating HIV-infected cells with pharmacological inhibitors of actin polymerization reduces HIV gene expression. We conclude that both direct and indirect effects of CYTOR regulate HIV gene expression.
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Affiliation(s)
- Alona Kuzmina
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel
| | - Lopamudra Sadhu
- Department of Infectious Diseases, Heidelberg University, Medical Faculty Heidelberg, Integrative Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg, Germany
| | - Md Hasanuzzaman
- Department of Infectious Diseases, Heidelberg University, Medical Faculty Heidelberg, Integrative Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg, Germany
| | - Koh Fujinaga
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
| | - Jacob C. Schwartz
- Department of Pharmacology, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - Oliver T. Fackler
- Department of Infectious Diseases, Heidelberg University, Medical Faculty Heidelberg, Integrative Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg. Germany
| | - Ran Taube
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel
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10
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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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Zhu L, Wang J, Wu Z, Chen S, He Y, Jiang Y, Luo G, Wu Z, Li Y, Xie J, Zou S, Zhou C. AFF4 regulates osteogenic potential of human periodontal ligament stem cells via mTOR-ULK1-autophagy axis. Cell Prolif 2024; 57:e13546. [PMID: 37731335 PMCID: PMC10849782 DOI: 10.1111/cpr.13546] [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: 06/20/2023] [Revised: 08/23/2023] [Accepted: 08/30/2023] [Indexed: 09/22/2023] Open
Abstract
Scaffold protein AF4/FMR2 family member 4 (AFF4) has been found to play a role in osteogenic commitment of stem cells. However, function of AFF4 in human periodontal ligament stem cells (hPDLSCs) has not been studied yet. This present study aims to investigate the biological effect of AFF4 on osteogenic differentiation of hPDLSCs and potential mechanistic pathway. First, AFF4 expression profile was evaluated in conditions of periodontitis and osteogenic differentiation of hPDLSCs by immunohistochemical staining, western blot and qRT-PCR. Next, si-RNA mediated knockdown and lentiviral transduction mediated overexpression of AFF4 were adopted to explore impact of AFF4 on osteogenic capacity of hPDLSCs. Then, possible mechanistic pathway was identified. At last, pharmacological agonist of autophagy, rapamycin, was utilized to affirm the role of autophagy in AFF4-regulated osteogenesis of hPDLSCs. First, AFF4 expressions were significantly lower in inflamed periodontal tissues and lipopolysaccharides-treated hPDLSCs than controls, and were up-regulated during osteogenic differentiation of hPDLSCs. Next, osteogenic potential of hPDLSCs was impaired by AFF4 knockdown and potentiated by AFF4 overexpression. Moreover, AFF4 was found to positively regulate autophagic activity in hPDLSCs. At last, rapamycin treatment was shown to be able to partly restore AFF4 knockdown-suppressed osteogenic differentiation. Our study demonstrates that AFF4 regulates osteogenic potential of hPDLSCs via targeting autophagic activity. The involvement of AFF4 in periodontal homeostasis was identified for the first time.
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Affiliation(s)
- Li Zhu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Jiahe Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Zuping Wu
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang ProvinceCancer Center of Zhejiang UniversityHangzhouChina
| | - Sirui Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Yuying He
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Yukun Jiang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Guowen Luo
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Zhuoxuan Wu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Yuyu Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Jing Xie
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Shujuan Zou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
- Department of Orthodontics, West China Hospital of StomatologySichuan UniversityChengduChina
| | - Chenchen Zhou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of StomatologySichuan UniversityChengduChina
- Department of Pediatric Dentistry, West China Hospital of StomatologySichuan UniversityChengduChina
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13
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Zhao J, Cato LD, Arora UP, Bao EL, Bryant SC, Williams N, Jia Y, Goldman SR, Nangalia J, Erb MA, Vos SM, Armstrong SA, Sankaran VG. Inherited blood cancer predisposition through altered transcription elongation. Cell 2024; 187:642-658.e19. [PMID: 38218188 PMCID: PMC10872907 DOI: 10.1016/j.cell.2023.12.016] [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: 06/06/2023] [Revised: 11/26/2023] [Accepted: 12/08/2023] [Indexed: 01/15/2024]
Abstract
Despite advances in defining diverse somatic mutations that cause myeloid malignancies, a significant heritable component for these cancers remains largely unexplained. Here, we perform rare variant association studies in a large population cohort to identify inherited predisposition genes for these blood cancers. CTR9, which encodes a key component of the PAF1 transcription elongation complex, is among the significant genes identified. The risk variants found in the cases cause loss of function and result in a ∼10-fold increased odds of acquiring a myeloid malignancy. Partial CTR9 loss of function expands human hematopoietic stem cells (HSCs) by increased super elongation complex-mediated transcriptional activity, which thereby increases the expression of key regulators of HSC self-renewal. By following up on insights from a human genetic study examining inherited predisposition to the myeloid malignancies, we define a previously unknown antagonistic interaction between the PAF1 and super elongation complexes. These insights could enable targeted approaches for blood cancer prevention.
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Affiliation(s)
- Jiawei Zhao
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA; Center for Cancer Immunology, Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen, China.
| | - Liam D Cato
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Uma P Arora
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Erik L Bao
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | | | - Nicholas Williams
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK; UK and MRC-Wellcome Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Yuemeng Jia
- Harvard Stem Cell Institute, Cambridge, MA, USA; Stem Cell Program, Boston Children's Hospital, Boston, MA, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | - Seth R Goldman
- Nascent Transcriptomics Core, Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Jyoti Nangalia
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK; UK and MRC-Wellcome Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Michael A Erb
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Seychelle M Vos
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Scott A Armstrong
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Vijay G Sankaran
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA; Harvard Stem Cell Institute, Cambridge, MA, USA.
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14
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Lin TL, Jaiswal AK, Ritter AJ, Reppas J, Tran TM, Neeb ZT, Katzman S, Thaxton ML, Cohen A, Sanford JR, Rao DS. Targeting IGF2BP3 enhances antileukemic effects of menin-MLL inhibition in MLL-AF4 leukemia. Blood Adv 2024; 8:261-275. [PMID: 38048400 PMCID: PMC10824693 DOI: 10.1182/bloodadvances.2023011132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 11/03/2023] [Accepted: 11/22/2023] [Indexed: 12/06/2023] Open
Abstract
ABSTRACT RNA-binding proteins (RBPs) are emerging as a novel class of therapeutic targets in cancer, including in leukemia, given their important role in posttranscriptional gene regulation, and have the unexplored potential to be combined with existing therapies. The RBP insulin-like growth factor 2 messenger RNA-binding protein 3 (IGF2BP3) has been found to be a critical regulator of MLL-AF4 leukemogenesis and represents a promising therapeutic target. Here, we study the combined effects of targeting IGF2BP3 and menin-MLL interaction in MLL-AF4-driven leukemia in vitro and in vivo, using genetic inhibition with CRISPR-Cas9-mediated deletion of Igf2bp3 and pharmacologic inhibition of the menin-MLL interaction with multiple commercially available inhibitors. Depletion of Igf2bp3 sensitized MLL-AF4 leukemia to the effects of menin-MLL inhibition on cell growth and leukemic initiating cells in vitro. Mechanistically, we found that both Igf2bp3 depletion and menin-MLL inhibition led to increased differentiation in vitro and in vivo, seen in functional readouts and by gene expression analyses. IGF2BP3 knockdown had a greater effect on increasing survival and attenuating disease than pharmacologic menin-MLL inhibition with small molecule MI-503 alone and showed enhanced antileukemic effects in combination. Our work shows that IGF2BP3 is an oncogenic amplifier of MLL-AF4-mediated leukemogenesis and a potent therapeutic target, providing a paradigm for targeting leukemia at both the transcriptional and posttranscriptional level.
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Affiliation(s)
- Tasha L. Lin
- Division of Hematology and Oncology, Department of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Amit K. Jaiswal
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Alexander J. Ritter
- Department of Molecular, Cell and Developmental Biology and Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, CA
| | - Jenna Reppas
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Tiffany M. Tran
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Zachary T. Neeb
- Department of Molecular, Cell and Developmental Biology and Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, CA
| | - Sol Katzman
- Center for Biomolecular Science & Engineering, University of California Santa Cruz, Santa Cruz, CA
| | - Michelle L. Thaxton
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Amanda Cohen
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Jeremy R. Sanford
- Department of Molecular, Cell and Developmental Biology and Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, CA
- Center for Biomolecular Science & Engineering, University of California Santa Cruz, Santa Cruz, CA
| | - Dinesh S. Rao
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA
- Broad Stem Cell Research Center, University of California, Los Angeles, Los Angeles, CA
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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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16
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Aoi Y, Shilatifard A. Transcriptional elongation control in developmental gene expression, aging, and disease. Mol Cell 2023; 83:3972-3999. [PMID: 37922911 DOI: 10.1016/j.molcel.2023.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/23/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
The elongation stage of transcription by RNA polymerase II (RNA Pol II) is central to the regulation of gene expression in response to developmental and environmental cues in metazoan. Dysregulated transcriptional elongation has been associated with developmental defects as well as disease and aging processes. Decades of genetic and biochemical studies have painstakingly identified and characterized an ensemble of factors that regulate RNA Pol II elongation. This review summarizes recent findings taking advantage of genetic engineering techniques that probe functions of elongation factors in vivo. We propose a revised model of elongation control in this accelerating field by reconciling contradictory results from the earlier biochemical evidence and the recent in vivo studies. We discuss how elongation factors regulate promoter-proximal RNA Pol II pause release, transcriptional elongation rate and processivity, RNA Pol II stability and RNA processing, and how perturbation of these processes is associated with developmental disorders, neurodegenerative disease, cancer, and aging.
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Affiliation(s)
- Yuki Aoi
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ali Shilatifard
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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17
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Johannessen JA, Formica M, Haukeland ALC, Bråthen NR, Al Outa A, Aarsund M, Therrien M, Enserink JM, Knævelsrud H. The human leukemic oncogene MLL-AF4 promotes hyperplastic growth of hematopoietic tissues in Drosophila larvae. iScience 2023; 26:107726. [PMID: 37720104 PMCID: PMC10504488 DOI: 10.1016/j.isci.2023.107726] [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: 12/11/2022] [Revised: 06/25/2023] [Accepted: 08/21/2023] [Indexed: 09/19/2023] Open
Abstract
MLL-rearranged (MLL-r) leukemias are among the leukemic subtypes with poorest survival, and treatment options have barely improved over the last decades. Despite increasing molecular understanding of the mechanisms behind these hematopoietic malignancies, this knowledge has had poor translation into the clinic. Here, we report a Drosophila melanogaster model system to explore the pathways affected in MLL-r leukemia. We show that expression of the human leukemic oncogene MLL-AF4 in the Drosophila hematopoietic system resulted in increased levels of circulating hemocytes and an enlargement of the larval hematopoietic organ, the lymph gland. Strikingly, depletion of Drosophila orthologs of known interactors of MLL-AF4, such as DOT1L, rescued the leukemic phenotype. In agreement, treatment with small-molecule inhibitors of DOT1L also prevented the MLL-AF4-induced leukemia-like phenotype. Taken together, this model provides an in vivo system to unravel the genetic interactors involved in leukemogenesis and offers a system for improved biological understanding of MLL-r leukemia.
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Affiliation(s)
- Julie A. Johannessen
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Miriam Formica
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Aina Louise C. Haukeland
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Nora Rojahn Bråthen
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Amani Al Outa
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Miriam Aarsund
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Marc Therrien
- Institute for Research in Immunology and Cancer, Laboratory of Intracellular Signaling, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
- Département de pathologie et de biologie cellulaire, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Jorrit M. Enserink
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Section for Biochemistry and Molecular Biology, The Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Helene Knævelsrud
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
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18
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Cameron DP, Grosser J, Ladigan S, Kuzin V, Iliopoulou E, Wiegard A, Benredjem H, Jackson K, Liffers ST, Lueong S, Cheung PF, Vangala D, Pohl M, Viebahn R, Teschendorf C, Wolters H, Usta S, Geng K, Kutter C, Arsenian-Henriksson M, Siveke JT, Tannapfel A, Schmiegel W, Hahn SA, Baranello L. Coinhibition of topoisomerase 1 and BRD4-mediated pause release selectively kills pancreatic cancer via readthrough transcription. SCIENCE ADVANCES 2023; 9:eadg5109. [PMID: 37831776 PMCID: PMC10575591 DOI: 10.1126/sciadv.adg5109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 09/13/2023] [Indexed: 10/15/2023]
Abstract
Pancreatic carcinoma lacks effective therapeutic strategies resulting in poor prognosis. Transcriptional dysregulation due to alterations in KRAS and MYC affects initiation, development, and survival of this tumor type. Using patient-derived xenografts of KRAS- and MYC-driven pancreatic carcinoma, we show that coinhibition of topoisomerase 1 (TOP1) and bromodomain-containing protein 4 (BRD4) synergistically induces tumor regression by targeting promoter pause release. Comparing the nascent transcriptome with the recruitment of elongation and termination factors, we found that coinhibition of TOP1 and BRD4 disrupts recruitment of transcription termination factors. Thus, RNA polymerases transcribe downstream of genes for hundreds of kilobases leading to readthrough transcription. This occurs during replication, perturbing replisome progression and inducing DNA damage. The synergistic effect of TOP1 + BRD4 inhibition is specific to cancer cells leaving normal cells unaffected, highlighting the tumor's vulnerability to transcriptional defects. This preclinical study provides a mechanistic understanding of the benefit of combining TOP1 and BRD4 inhibitors to treat pancreatic carcinomas addicted to oncogenic drivers of transcription and replication.
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Affiliation(s)
- Donald P. Cameron
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jan Grosser
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Swetlana Ladigan
- Ruhr University Bochum, Faculty of Medicine, Department of Molecular GI Oncology, Bochum, Germany
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Vladislav Kuzin
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Evanthia Iliopoulou
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Anika Wiegard
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Hajar Benredjem
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Kathryn Jackson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Sven T. Liffers
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | - Smiths Lueong
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | - Phyllis F. Cheung
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | - Deepak Vangala
- Ruhr University Bochum, Faculty of Medicine, Department of Molecular GI Oncology, Bochum, Germany
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Michael Pohl
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Richard Viebahn
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Surgery, Bochum, Germany
| | | | - Heiner Wolters
- Department of Visceral and General Surgery, St. Josef-Hospital, Dortmund, Germany
| | - Selami Usta
- Department of Visceral and General Surgery, St. Josef-Hospital, Dortmund, Germany
| | - Keyi Geng
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Claudia Kutter
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | | | - Jens T. Siveke
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | | | - Wolff Schmiegel
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Stephan A. Hahn
- Ruhr University Bochum, Faculty of Medicine, Department of Molecular GI Oncology, Bochum, Germany
| | - Laura Baranello
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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19
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Mascarenhas R, Meirelles PM, Batalha-Filho H. Urbanization drives adaptive evolution in a Neotropical bird. Curr Zool 2023; 69:607-619. [PMID: 37637315 PMCID: PMC10449428 DOI: 10.1093/cz/zoac066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 08/16/2022] [Indexed: 08/29/2023] Open
Abstract
Urbanization has dramatic impacts on natural habitats and such changes may potentially drive local adaptation of urban populations. Behavioral change has been specifically shown to facilitate the fast adaptation of birds to changing environments, but few studies have investigated the genetic mechanisms of this process. Such investigations could provide insights into questions about both evolutionary theory and management of urban populations. In this study, we investigated whether local adaptation has occurred in urban populations of a Neotropical bird species, Coereba flaveola, specifically addressing whether observed behavioral adaptations are correlated to genetic signatures of natural selection. To answer this question, we sampled 24 individuals in urban and rural environments, and searched for selected loci through a genome-scan approach based on RADseq genomic data, generated and assembled using a reference genome for the species. We recovered 46 loci as putative selection outliers, and 30 of them were identified as associated with biological processes possibly related to urban adaptation, such as the regulation of energetic metabolism, regulation of genetic expression, and changes in the immunological system. Moreover, genes involved in the development of the nervous system showed signatures of selection, suggesting a link between behavioral and genetic adaptations. Our findings, in conjunction with similar results in previous studies, support the idea that cities provide a similar selective pressure on urban populations and that behavioral plasticity may be enhanced through genetic changes in urban populations.
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Affiliation(s)
- Rilquer Mascarenhas
- National Institute of Science and Technology in Interdisciplinary and Transdisciplinary Studies in Ecology and Evolution (INCT IN-TREE), Instituto de Biologia, Universidade Federal da Bahia, 40170-115 Salvador, Bahia, Brazil
| | - Pedro Milet Meirelles
- National Institute of Science and Technology in Interdisciplinary and Transdisciplinary Studies in Ecology and Evolution (INCT IN-TREE), Instituto de Biologia, Universidade Federal da Bahia, 40170-115 Salvador, Bahia, Brazil
| | - Henrique Batalha-Filho
- National Institute of Science and Technology in Interdisciplinary and Transdisciplinary Studies in Ecology and Evolution (INCT IN-TREE), Instituto de Biologia, Universidade Federal da Bahia, 40170-115 Salvador, Bahia, Brazil
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20
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Pluta AJ, Studniarek C, Murphy S, Norbury CJ. Cyclin-dependent kinases: Masters of the eukaryotic universe. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 15:e1816. [PMID: 37718413 PMCID: PMC10909489 DOI: 10.1002/wrna.1816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/21/2023] [Accepted: 08/03/2023] [Indexed: 09/19/2023]
Abstract
A family of structurally related cyclin-dependent protein kinases (CDKs) drives many aspects of eukaryotic cell function. Much of the literature in this area has considered individual members of this family to act primarily either as regulators of the cell cycle, the context in which CDKs were first discovered, or as regulators of transcription. Until recently, CDK7 was the only clear example of a CDK that functions in both processes. However, new data points to several "cell-cycle" CDKs having important roles in transcription and some "transcriptional" CDKs having cell cycle-related targets. For example, novel functions in transcription have been demonstrated for the archetypal cell cycle regulator CDK1. The increasing evidence of the overlap between these two CDK types suggests that they might play a critical role in coordinating the two processes. Here we review the canonical functions of cell-cycle and transcriptional CDKs, and provide an update on how these kinases collaborate to perform important cellular functions. We also provide a brief overview of how dysregulation of CDKs contributes to carcinogenesis, and possible treatment avenues. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Processing > 3' End Processing RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | | | - Shona Murphy
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | - Chris J. Norbury
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
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21
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Ghosh A, Chakraborty P, Biswas D. Fine tuning of the transcription juggernaut: A sweet and sour saga of acetylation and ubiquitination. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194944. [PMID: 37236503 DOI: 10.1016/j.bbagrm.2023.194944] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/26/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
Among post-translational modifications of proteins, acetylation, phosphorylation, and ubiquitination are most extensively studied over the last several decades. Owing to their different target residues for modifications, cross-talk between phosphorylation with that of acetylation and ubiquitination is relatively less pronounced. However, since canonical acetylation and ubiquitination happen only on the lysine residues, an overlap of the same lysine residue being targeted for both acetylation and ubiquitination happens quite frequently and thus plays key roles in overall functional regulation predominantly through modulation of protein stability. In this review, we discuss the cross-talk of acetylation and ubiquitination in the regulation of protein stability for the functional regulation of cellular processes with an emphasis on transcriptional regulation. Further, we emphasize our understanding of the functional regulation of Super Elongation Complex (SEC)-mediated transcription, through regulation of stabilization by acetylation, deacetylation and ubiquitination and associated enzymes and its implication in human diseases.
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Affiliation(s)
- Avik Ghosh
- Laboratory of Transcription Biology Molecular Genetics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 32, India
| | - Poushali Chakraborty
- Laboratory of Transcription Biology Molecular Genetics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 32, 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.
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22
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Meng S, Liu X, Zhu S, Xie P, Fang H, Pan Q, Fang K, Li F, Zhang J, Che Z, Zhang Q, Mao G, Wang Y, Hu P, Chen K, Sun F, Xie W, Luo Z, Lin C. Young LINE-1 transposon 5' UTRs marked by elongation factor ELL3 function as enhancers to regulate naïve pluripotency in embryonic stem cells. Nat Cell Biol 2023; 25:1319-1331. [PMID: 37591949 DOI: 10.1038/s41556-023-01211-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 07/19/2023] [Indexed: 08/19/2023]
Abstract
LINE-1s are the major clade of retrotransposons with autonomous retrotransposition activity. Despite the potential genotoxicity, LINE-1s are highly activated in early embryos. Here we show that a subset of young LINE-1s, L1Md_Ts, are marked by the RNA polymerase II elongation factor ELL3, and function as enhancers in mouse embryonic stem cells. ELL3 depletion dislodges the DNA hydroxymethylase TET1 and the co-repressor SIN3A from L1Md_Ts, but increases the enrichment of the Bromodomain protein BRD4, leading to loss of 5hmC, gain of H3K27ac, and upregulation of the L1Md_T nearby genes. Specifically, ELL3 occupies and represses the L1Md_T-based enhancer located within Akt3, which encodes a key regulator of AKT pathway. ELL3 is required for proper ERK activation and efficient shutdown of naïve pluripotency through inhibiting Akt3 during naïve-primed transition. Our study reveals that the enhancer function of a subset of young LINE-1s controlled by ELL3 in transcription regulation and mouse early embryo development.
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Affiliation(s)
- Siyan Meng
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xiaoxu Liu
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Shiqi Zhu
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Peng Xie
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haitong Fang
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Qingyun Pan
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Ke Fang
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Fanfan Li
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Jin Zhang
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Zhuanzhuan Che
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Quanyong Zhang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, China
| | - Guangyao Mao
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Yan Wang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Ping Hu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Kai Chen
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, China
| | - Fei Sun
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Wei Xie
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Zhuojuan Luo
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China.
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Southeast University, Nanjing, China.
- Shenzhen Research Institute, Southeast University, Shenzhen, China.
| | - Chengqi Lin
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China.
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.
- Shenzhen Research Institute, Southeast University, Shenzhen, China.
- Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing, China.
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23
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Xu W, Li X. Regulation of Pol II Pausing during Daily Gene Transcription in Mouse Liver. BIOLOGY 2023; 12:1107. [PMID: 37626993 PMCID: PMC10452108 DOI: 10.3390/biology12081107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/20/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023]
Abstract
Cell autonomous circadian oscillation is present in central and various peripheral tissues. The intrinsic tissue clock and various extrinsic cues drive gene expression rhythms. Transcription regulation is thought to be the main driving force for gene rhythms. However, how transcription rhythms arise remains to be fully characterized due to the fact that transcription is regulated at multiple steps. In particular, Pol II recruitment, pause release, and premature transcription termination are critical regulatory steps that determine the status of Pol II pausing and transcription output near the transcription start site (TSS) of the promoter. Recently, we showed that Pol II pausing exhibits genome-wide changes during daily transcription in mouse liver. In this article, we review historical as well as recent findings on the regulation of transcription rhythms by the circadian clock and other transcription factors, and the potential limitations of those results in explaining rhythmic transcription at the TSS. We then discuss our results on the genome-wide characteristics of daily changes in Pol II pausing, the possible regulatory mechanisms involved, and their relevance to future research on circadian transcription regulation.
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Affiliation(s)
| | - Xiaodong Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China;
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24
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Hu H, Muntean AG. The YEATS domain epigenetic reader proteins ENL and AF9 and their therapeutic value in leukemia. Exp Hematol 2023; 124:15-21. [PMID: 37295550 PMCID: PMC10527611 DOI: 10.1016/j.exphem.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Recent studies have uncovered similarities and differences between 2 highly homologous epigenetic reading proteins, namely, ENL (MLLT1) and AF9 (MLLT3) with therapeutic implications. The importance of these proteins has traditionally been exemplified by their involvement in chromosomal translocations with the mixed-lineage leukemia gene (MLL; aka KMT2a). MLL rearrangements occur in a subset of acute leukemias and generate potent oncogenic MLL-fusion proteins that impact epigenetic and transcriptional regulation. Leukemic patients with MLL rearrangements display intermediate-to-poor prognoses, necessitating further mechanistic research. Several protein complexes involved in regulating RNA polymerase II transcription and the epigenetic landscape are hijacked in MLL-r leukemia, which include ENL and AF9. Recent biochemical studies have defined a highly homologous YEATS domain in ENL and AF9 that binds acylated histones, which aids in the localization and retention of these proteins to transcriptional targets. In addition, detailed characterization of the homologous ANC-1 homology domain (AHD) on ENL and AF9 revealed differential association with transcriptional activating and repressing complexes. Importantly, CRISPR knockout screens have demonstrated a unique role for wild-type ENL in leukemic stem cell function, whereas AF9 appears important for normal hematopoietic stem cells. In this perspective, we examine the ENL and AF9 proteins with attention to recent work characterizing the epigenetic reading YEATS domains and AHD on both wild-type proteins and when fused to MLL. We summarized the drug development efforts and their therapeutic potential and assess ongoing research that has refined our understanding of how these proteins function, which continues to reveal new therapeutic avenues.
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Affiliation(s)
- Hsiangyu Hu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI
| | - Andrew G Muntean
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI.
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25
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Chen M. CircR-looping the leukemic translocations: The cause of MLL translocations explained. Mol Cell 2023; 83:2164-2166. [PMID: 37419090 DOI: 10.1016/j.molcel.2023.05.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 05/31/2023] [Accepted: 05/31/2023] [Indexed: 07/09/2023]
Abstract
Conn et al.1 identify circular RNAs (circRNAs) derived from mixed lineage leukemia (MLL) breakpoint cluster regions, demonstrating a causal role of circRNAs in MLL translocations. CircRNAs:DNA hybrids (circR-loops) trigger RNA polymerase pausing, driving oncogenic gene fusions via endogenous RNA-directed DNA damage.
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Affiliation(s)
- Mo Chen
- State Key Laboratory of Molecular Oncology, School of Medicine, Tsinghua University, Beijing, China 100084.
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26
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Shao J, Shi T, Chen L, Wang X, Yu H, Feng N, Wang X. AF9 targets acetyl-modified STAT6 to diminish purine metabolism and accelerate cell apoptosis during metastasis. Cell Death Differ 2023; 30:1695-1709. [PMID: 37308587 PMCID: PMC10307824 DOI: 10.1038/s41418-023-01172-7] [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: 08/04/2022] [Revised: 04/14/2023] [Accepted: 04/25/2023] [Indexed: 06/14/2023] Open
Abstract
Cell migration and invasion are two important steps for tumour metastasis, and involved the behaviors including metabolism remodeling and anti-apoptosis. However, it's still elusive that cancer cells how to antagonize apoptosis during tumour metastasis. In this study, we observed that super elongation complex (SEC) subunit AF9 depletion exacerbated cell migration and invasion but reduced the apoptosis during invasive migration. Mechanically, AF9 targeted acetyl (Ac)-STAT6 at lysine (K) 284 and blocked STAT6 transactivation on the promoter of such genes involved in regulating purine metabolism and metastasis, in turn induced apoptosis of suspended cells. Of note, AcSTAT6-K284 was not induced by IL4 signaling but decreased by limited nutrition which triggered SIRT6 to remove acetyl group at STAT6-K284. The functional experiments proved that AcSTAT6-K284 attenuated cell migration and invasion depending on AF9 expression level. Animal metastatic study further confirmed the AF9/AcSTAT6-K284 axis existed and blocked kidney renal clear cell carcinoma (KIRC) metastasis. In clinical, both AF9 expression and AcSTAT6-K284 were decreased accompanied by the advanced tumour grade and positively correlated with KIRC patients' survival. Conclusively, we explored an inhibitory axis which not only suppressed tumour metastasis but also could be utilized for drug development to hamper KIRC metastasis.
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Affiliation(s)
- Jialiang Shao
- Department of Urology, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, 200080, China
| | - Tiezhu Shi
- School of Life Sciences, Guangzhou University, Guangzhou, 510006, China
| | - Lianheng Chen
- School of Life Sciences, Guangzhou University, Guangzhou, 510006, China
| | - Xiang Wang
- Department of Urology, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, 200080, China
| | - Hua Yu
- School of Life Sciences, Guangzhou University, Guangzhou, 510006, China.
| | - Ninghan Feng
- Department of Urology, The Affiliated Wuxi No.2 Hospital of Nanjing Medical University, Jiangsu, 214002, China.
| | - Xiongjun Wang
- School of Life Sciences, Guangzhou University, Guangzhou, 510006, China.
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27
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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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28
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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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29
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Shin YH, Kim DE, Yu KL, Park CM, Kim HG, Kim KC, Bae S, Yoon CH. A Novel Time-Resolved Fluorescence Resonance Energy Transfer Assay for the Discovery of Small-Molecule Inhibitors of HIV-1 Tat-Regulated Transcription. Int J Mol Sci 2023; 24:ijms24119139. [PMID: 37298089 DOI: 10.3390/ijms24119139] [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: 05/02/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) transactivator (Tat)-mediated transcription is essential for HIV-1 replication. It is determined by the interaction between Tat and transactivation response (TAR) RNA, a highly conserved process representing a prominent therapeutic target against HIV-1 replication. However, owing to the limitations of current high-throughput screening (HTS) assays, no drug that disrupts the Tat-TAR RNA interaction has been uncovered yet. We designed a homogenous (mix-and-read) time-resolved fluorescence resonance energy transfer (TR-FRET) assay using europium cryptate as a fluorescence donor. It was optimized by evaluating different probing systems for Tat-derived peptides or TAR RNA. The specificity of the optimal assay was validated by mutants of the Tat-derived peptides and TAR RNA fragment, individually and by competitive inhibition with known TAR RNA-binding peptides. The assay generated a constant Tat-TAR RNA interaction signal, discriminating the compounds that disrupted the interaction. Combined with a functional assay, the TR-FRET assay identified two small molecules (460-G06 and 463-H08) capable of inhibiting Tat activity and HIV-1 infection from a large-scale compound library. The simplicity, ease of operation, and rapidity of our assay render it suitable for HTS to identify Tat-TAR RNA interaction inhibitors. The identified compounds may also act as potent molecular scaffolds for developing a new HIV-1 drug class.
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Affiliation(s)
- Young Hyun Shin
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Dong-Eun Kim
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Kyung Lee Yu
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Chul Min Park
- Department for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Daejeon 34114, Republic of Korea
| | - Hong Gi Kim
- Department for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Daejeon 34114, Republic of Korea
| | - Kyung-Chang Kim
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Songmee Bae
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Cheol-Hee Yoon
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
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Kim SH, Nichols KD, Anderson EN, Liu Y, Ramesh N, Jia W, Kuerbis CJ, Scalf M, Smith LM, Pandey UB, Tibbetts RS. Axon guidance genes modulate neurotoxicity of ALS-associated UBQLN2. eLife 2023; 12:e84382. [PMID: 37039476 PMCID: PMC10147378 DOI: 10.7554/elife.84382] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 04/06/2023] [Indexed: 04/12/2023] Open
Abstract
Mutations in the ubiquitin (Ub) chaperone Ubiquilin 2 (UBQLN2) cause X-linked forms of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) through unknown mechanisms. Here, we show that aggregation-prone, ALS-associated mutants of UBQLN2 (UBQLN2ALS) trigger heat stress-dependent neurodegeneration in Drosophila. A genetic modifier screen implicated endolysosomal and axon guidance genes, including the netrin receptor, Unc-5, as key modulators of UBQLN2 toxicity. Reduced gene dosage of Unc-5 or its coreceptor Dcc/frazzled diminished neurodegenerative phenotypes, including motor dysfunction, neuromuscular junction defects, and shortened lifespan, in flies expressing UBQLN2ALS alleles. Induced pluripotent stem cells (iPSCs) harboring UBQLN2ALS knockin mutations exhibited lysosomal defects while inducible motor neurons (iMNs) expressing UBQLN2ALS alleles exhibited cytosolic UBQLN2 inclusions, reduced neurite complexity, and growth cone defects that were partially reversed by silencing of UNC5B and DCC. The combined findings suggest that altered growth cone dynamics are a conserved pathomechanism in UBQLN2-associated ALS/FTD.
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Affiliation(s)
- Sang Hwa Kim
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Kye D Nichols
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Eric N Anderson
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Yining Liu
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Nandini Ramesh
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Weiyan Jia
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Connor J Kuerbis
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Mark Scalf
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Udai Bhan Pandey
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Randal S Tibbetts
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
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Liu W, Lin S, Li L, Tai Z, Liu JX. Zebrafish ELL-associated factors Eaf1/2 modulate erythropoiesis via regulating gata1a expression and WNT signaling to facilitate hypoxia tolerance. CELL REGENERATION (LONDON, ENGLAND) 2023; 12:10. [PMID: 37002435 PMCID: PMC10066051 DOI: 10.1186/s13619-022-00154-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 11/28/2022] [Indexed: 04/04/2023]
Abstract
EAF1 and EAF2, the eleven-nineteen lysine-rich leukemia (ELL)-associated factors which can assemble to the super elongation complex (AFF1/4, AF9/ENL, ELL, and P-TEFb), are reported to participate in RNA polymerase II to actively regulate a variety of biological processes, including leukemia and embryogenesis, but whether and how EAF1/2 function in hematopoietic system related hypoxia tolerance during embryogenesis remains unclear. Here, we unveiled that deletion of EAF1/2 (eaf1-/- and eaf2-/-) caused reduction in hypoxia tolerance in zebrafish, leading to reduced erythropoiesis during hematopoietic processes. Meanwhile, eaf1-/- and eaf2-/- mutants showed significant reduction in the expression of key transcriptional regulators scl, lmo2, and gata1a in erythropoiesis at both 24 h post fertilization (hpf) and 72 hpf, with gata1a downregulated while scl and lmo2 upregulated at 14 hpf. Mechanistically, eaf1-/- and eaf2-/- mutants exhibited significant changes in the expression of epigenetic modified histones, with a significant increase in the binding enrichment of modified histone H3K27me3 in gata1a promoter rather than scl and lmo2 promoters. Additionally, eaf1-/- and eaf2-/- mutants exhibited a dynamic expression of canonical WNT/β-catenin signaling during erythropoiesis, with significant reduction in p-β-Catenin level and in the binding enrichment of both scl and lmo2 promoters with the WNT transcriptional factor TCF4 at 24 hpf. These findings demonstrate an important role of Eaf1/2 in erythropoiesis in zebrafish and may have shed some light on regeneration medicine for anemia and related diseases and on molecular basis for fish economic or productive traits, such as growth, disease resistance, hypoxia tolerance, and so on.
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Affiliation(s)
- WenYe Liu
- grid.35155.370000 0004 1790 4137College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, 430070 Wuhan, China
| | - ShuHui Lin
- grid.35155.370000 0004 1790 4137College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, 430070 Wuhan, China
| | - LingYa Li
- grid.35155.370000 0004 1790 4137College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, 430070 Wuhan, China
| | - ZhiPeng Tai
- grid.35155.370000 0004 1790 4137College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, 430070 Wuhan, China
| | - Jing-Xia Liu
- grid.35155.370000 0004 1790 4137College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, 430070 Wuhan, China
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32
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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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Wang D, Yin Z, Wang H, Wang L, Li T, Xiao R, Xie T, Han R, Dong R, Liu H, Liang K, Qing G. The super elongation complex drives transcriptional addiction in MYCN-amplified neuroblastoma. SCIENCE ADVANCES 2023; 9:eadf0005. [PMID: 36989355 PMCID: PMC10058231 DOI: 10.1126/sciadv.adf0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
MYCN amplification in neuroblastoma leads to aberrant expression of MYCN oncoprotein, which binds active genes promoting transcriptional amplification. Yet, how MYCN coordinates transcription elongation to meet productive transcriptional amplification and which elongation machinery represents MYCN-driven vulnerability remain to be identified. We conducted a targeted screen of transcription elongation factors and identified the super elongation complex (SEC) as a unique vulnerability in MYCN-amplified neuroblastomas. MYCN directly binds EAF1 and recruits SEC to enhance processive transcription elongation. Depletion of EAF1 or AFF1/AFF4, another core subunit of SEC, leads to a global reduction in transcription elongation and elicits selective apoptosis of MYCN-amplified neuroblastoma cells. A combination screen reveals SEC inhibition synergistically potentiates the therapeutic efficacies of FDA-approved BCL-2 antagonist ABT-199, in part due to suppression of MCL1 expression, both in MYCN-amplified neuroblastoma cells and in patient-derived xenografts. These findings identify disruption of the MYCN-SEC regulatory axis as a promising therapeutic strategy in neuroblastoma.
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Affiliation(s)
- Donghai Wang
- Department of Urology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Zhinang Yin
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Honghong Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Liyuan Wang
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Tianyu Li
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Ruijing Xiao
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
- Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Ting Xie
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Ruyi Han
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Rui Dong
- Department of Pediatric Surgery, Children’s Hospital of Fudan University and Shanghai Key Laboratory of Birth Defects, Shanghai 201102, China
| | - Hudan Liu
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Kaiwei Liang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
- Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Guoliang Qing
- Department of Urology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
- Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan 430071, China
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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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Yfantis A, Mylonis I, Chachami G, Nikolaidis M, Amoutzias GD, Paraskeva E, Simos G. Transcriptional Response to Hypoxia: The Role of HIF-1-Associated Co-Regulators. Cells 2023; 12:cells12050798. [PMID: 36899934 PMCID: PMC10001186 DOI: 10.3390/cells12050798] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/22/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
The Hypoxia Inducible Factor 1 (HIF-1) plays a major role in the cellular response to hypoxia by regulating the expression of many genes involved in adaptive processes that allow cell survival under low oxygen conditions. Adaptation to the hypoxic tumor micro-environment is also critical for cancer cell proliferation and therefore HIF-1 is also considered a valid therapeutical target. Despite the huge progress in understanding regulation of HIF-1 expression and activity by oxygen levels or oncogenic pathways, the way HIF-1 interacts with chromatin and the transcriptional machinery in order to activate its target genes is still a matter of intense investigation. Recent studies have identified several different HIF-1- and chromatin-associated co-regulators that play important roles in the general transcriptional activity of HIF-1, independent of its expression levels, as well as in the selection of binding sites, promoters and target genes, which, however, often depends on cellular context. We review here these co-regulators and examine their effect on the expression of a compilation of well-characterized HIF-1 direct target genes in order to assess the range of their involvement in the transcriptional response to hypoxia. Delineating the mode and the significance of the interaction between HIF-1 and its associated co-regulators may offer new attractive and specific targets for anticancer therapy.
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Affiliation(s)
- Angelos Yfantis
- Laboratory of Biochemistry, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece; (A.Y.); (I.M.); (G.C.)
| | - Ilias Mylonis
- Laboratory of Biochemistry, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece; (A.Y.); (I.M.); (G.C.)
| | - Georgia Chachami
- Laboratory of Biochemistry, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece; (A.Y.); (I.M.); (G.C.)
| | - Marios Nikolaidis
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece; (M.N.); (G.D.A.)
| | - Grigorios D. Amoutzias
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece; (M.N.); (G.D.A.)
| | - Efrosyni Paraskeva
- Laboratory of Physiology, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece;
| | - George Simos
- Laboratory of Biochemistry, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece; (A.Y.); (I.M.); (G.C.)
- Gerald Bronfman Department of Oncology, Faculty of Medicine, McGill University, Montreal, QC H4A 3T2, Canada
- Correspondence:
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Welsh SA, Gardini A. Genomic regulation of transcription and RNA processing by the multitasking Integrator complex. Nat Rev Mol Cell Biol 2023; 24:204-220. [PMID: 36180603 PMCID: PMC9974566 DOI: 10.1038/s41580-022-00534-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2022] [Indexed: 11/09/2022]
Abstract
In higher eukaryotes, fine-tuned activation of protein-coding genes and many non-coding RNAs pivots around the regulated activity of RNA polymerase II (Pol II). The Integrator complex is the only Pol II-associated large multiprotein complex that is metazoan specific, and has therefore been understudied for years. Integrator comprises at least 14 subunits, which are grouped into distinct functional modules. The phosphodiesterase activity of the core catalytic module is co-transcriptionally directed against several RNA species, including long non-coding RNAs (lncRNAs), U small nuclear RNAs (U snRNAs), PIWI-interacting RNAs (piRNAs), enhancer RNAs and nascent pre-mRNAs. Processing of non-coding RNAs by Integrator is essential for their biogenesis, and at protein-coding genes, Integrator is a key modulator of Pol II promoter-proximal pausing and transcript elongation. Recent studies have identified an Integrator-specific serine/threonine-protein phosphatase 2A (PP2A) module, which targets Pol II and other components of the basal transcription machinery. In this Review, we discuss how the activity of Integrator regulates transcription, RNA processing, chromatin landscape and DNA repair. We also discuss the diverse roles of Integrator in development and tumorigenesis.
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Akcan TS, Vilov S, Heinig M. Predictive model of transcriptional elongation control identifies trans regulatory factors from chromatin signatures. Nucleic Acids Res 2023; 51:1608-1624. [PMID: 36727445 PMCID: PMC9976927 DOI: 10.1093/nar/gkac1272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/09/2022] [Accepted: 01/12/2023] [Indexed: 02/03/2023] Open
Abstract
Promoter-proximal Polymerase II (Pol II) pausing is a key rate-limiting step for gene expression. DNA and RNA-binding trans-acting factors regulating the extent of pausing have been identified. However, we lack a quantitative model of how interactions of these factors determine pausing, therefore the relative importance of implicated factors is unknown. Moreover, previously unknown regulators might exist. Here we address this gap with a machine learning model that accurately predicts the extent of promoter-proximal Pol II pausing from large-scale genome and transcriptome binding maps and gene annotation and sequence composition features. We demonstrate high accuracy and generalizability of the model by validation on an independent cell line which reveals the model's cell line agnostic character. Model interpretation in light of prior knowledge about molecular functions of regulatory factors confirms the interconnection of pausing with other RNA processing steps. Harnessing underlying feature contributions, we assess the relative importance of each factor, quantify their predictive effects and systematically identify previously unknown regulators of pausing. We additionally identify 16 previously unknown 7SK ncRNA interacting RNA-binding proteins predictive of pausing. Our work provides a framework to further our understanding of the regulation of the critical early steps in transcriptional elongation.
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Affiliation(s)
- Toray S Akcan
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.,Department of Computer Science, TUM School of Computation, Information and Technology, Technical University Munich, Munich, Germany
| | - Sergey Vilov
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Matthias Heinig
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.,Department of Computer Science, TUM School of Computation, Information and Technology, Technical University Munich, Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Munich Heart Association, Partner Site Munich, 10785 Berlin, Germany
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Boddu PC, Gupta A, Roy R, De La Pena Avalos B, Herrero AO, Neuenkirchen N, Zimmer J, Chandhok N, King D, Nannya Y, Ogawa S, Lin H, Simon M, Dray E, Kupfer G, Verma AK, Neugebauer KM, Pillai MM. Transcription elongation defects link oncogenic splicing factor mutations to targetable alterations in chromatin landscape. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.25.530019. [PMID: 36891287 PMCID: PMC9994134 DOI: 10.1101/2023.02.25.530019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Transcription and splicing of pre-messenger RNA are closely coordinated, but how this functional coupling is disrupted in human disease remains unexplored. Here, we investigated the impact of non-synonymous mutations in SF3B1 and U2AF1, two commonly mutated splicing factors in cancer, on transcription. We find that the mutations impair RNA Polymerase II (RNAPII) transcription elongation along gene bodies leading to transcription-replication conflicts, replication stress and altered chromatin organization. This elongation defect is linked to disrupted pre-spliceosome assembly due to impaired association of HTATSF1 with mutant SF3B1. Through an unbiased screen, we identified epigenetic factors in the Sin3/HDAC complex, which, when modulated, normalize transcription defects and their downstream effects. Our findings shed light on the mechanisms by which oncogenic mutant spliceosomes impact chromatin organization through their effects on RNAPII transcription elongation and present a rationale for targeting the Sin3/HDAC complex as a potential therapeutic strategy. GRAPHICAL ABSTRACT HIGHLIGHTS Oncogenic mutations of SF3B1 and U2AF1 cause a gene-body RNAPII elongation defectRNAPII transcription elongation defect leads to transcription replication conflicts, DNA damage response, and changes to chromatin organization and H3K4me3 marksThe transcription elongation defect is linked to disruption of the early spliceosome formation through impaired interaction of HTATSF1 with mutant SF3B1.Changes to chromatin organization reveal potential therapeutic strategies by targeting the Sin3/HDAC pathway.
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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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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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Aryal S, Zhang Y, Wren S, Li C, Lu R. Molecular regulators of HOXA9 in acute myeloid leukemia. FEBS J 2023; 290:321-339. [PMID: 34743404 DOI: 10.1111/febs.16268] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 09/30/2021] [Accepted: 11/05/2021] [Indexed: 02/05/2023]
Abstract
Dysregulation of the oncogenic transcription factor HOXA9 is a prominent feature for most aggressive acute myeloid leukemia cases and a strong indicator of poor prognosis in patients. Leukemia subtypes with hallmark overexpression of HOXA9 include those carrying MLL gene rearrangements, NPM1c mutations, and other genetic alternations. A growing body of evidence indicates that HOXA9 dysregulation is both sufficient and necessary for leukemic transformation. The HOXA9 mRNA and protein regulation includes multilayered controls by transcription factors (such as CDX2/4 and USF2/1), epigenetic factors (such as MLL-menin-LEDGF, DOT1L, ENL, HBO1, NPM1c-XPO1, and polycomb proteins), microRNAs (such as miR-126 and miR-196b), long noncoding RNAs (such as HOTTIP), three-dimensional chromatin interactions, and post-translational protein modifications. Recently, insights into the dynamic regulation of HOXA9 have led to an advanced understanding of the HOXA9 regulome and provided new cancer therapeutic opportunities, including developing inhibitors targeting DOT1L, menin, and ENL proteins. This review summarizes recent advances in understanding the molecular mechanisms controlling HOXA9 regulation and the pharmacological approaches that target HOXA9 regulators to treat HOXA9-driven acute myeloid leukemia.
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Affiliation(s)
- Sajesan Aryal
- Division of Hematology and Oncology & O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, AL, USA
| | - Yang Zhang
- Department of Tumor Cell Biology & Cancer Biology Program/Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Spencer Wren
- Division of Hematology and Oncology & O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, AL, USA
| | - Chunliang Li
- Department of Tumor Cell Biology & Cancer Biology Program/Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Rui Lu
- Division of Hematology and Oncology & O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, AL, USA
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Siemund AL, Hanewald T, Kowarz E, Marschalek R. MLL-AF4 and a murinized pSer-variant thereof are turning on the nucleolar stress pathway. Cell Biosci 2022; 12:47. [PMID: 35468859 PMCID: PMC9036721 DOI: 10.1186/s13578-022-00781-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 03/29/2022] [Indexed: 11/22/2022] Open
Abstract
Background Recent pathomolecular studies on the MLL-AF4 fusion protein revealed that the murinized version of MLL-AF4, the MLL-Af4 fusion protein, was able to induce leukemia when expressed in murine or human hematopoietic stem/progenitor cells (Lin et al. in Cancer Cell 30:737–749, 2016). In parallel, a group from Japan demonstrated that the pSer domain of the AF4 protein, as well as the pSer domain of the MLL-AF4 fusion is able to bind the Pol I transcription factor complex SL1 (Okuda et al. in Nat Commun 6:8869, 2015). Here, we investigated the human MLL-AF4 and a pSer-murinized version thereof for their functional properties in mammalian cells. Gene expression profiling studies were complemented by intracellular localization studies and functional experiments concerning their biological activities in the nucleolus. Results Based on our results, we have to conclude that MLL-AF4 is predominantly localizing inside the nucleolus, thereby interfering with Pol I transcription and ribosome biogenesis. The murinized pSer-variant is localizing more to the nucleus, which may suggest a different biological behavior. Of note, AF4-MLL seems to cooperate at the molecular level with MLL-AF4 to steer target gene transcription, but not with the pSer-murinized version of it. Conclusion This study provides new insights and a molecular explanation for the described differences between hMLL-hAF4 (not leukemogenic) and hMLL-mAf4 (leukemogenic). While the human pSer domain is able to efficiently recruit the SL1 transcription factor complex, the murine counterpart seems to be not. This has several consequences for our understanding of t(4;11) leukemia which is the most frequent leukemia in infants, childhood and adults suffering from MLL-r acute leukemia. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00781-y.
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Markouli M, Strepkos D, Piperi C. Impact of Histone Modifications and Their Therapeutic Targeting in Hematological Malignancies. Int J Mol Sci 2022; 23:13657. [PMID: 36362442 PMCID: PMC9654260 DOI: 10.3390/ijms232113657] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
Hematologic malignancies are a large and heterogeneous group of neoplasms characterized by complex pathogenetic mechanisms. The abnormal regulation of epigenetic mechanisms and specifically, histone modifications, has been demonstrated to play a central role in hematological cancer pathogenesis and progression. A variety of epigenetic enzymes that affect the state of histones have been detected as deregulated, being either over- or underexpressed, which induces changes in chromatin compaction and, subsequently, affects gene expression. Recent advances in the field of epigenetics have revealed novel therapeutic targets, with many epigenetic drugs being investigated in clinical trials. The present review focuses on the biological impact of histone modifications in the pathogenesis of hematologic malignancies, describing a wide range of therapeutic agents that have been discovered to target these alterations and are currently under investigation in clinical trials.
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Affiliation(s)
| | | | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (M.M.); (D.S.)
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Pal S, Yadav D, Biswas D. ATM-mediated ELL phosphorylation enhances its self-association through increased EAF1 interaction and inhibits global transcription during genotoxic stress. Nucleic Acids Res 2022; 50:10995-11012. [PMID: 36305813 PMCID: PMC9638944 DOI: 10.1093/nar/gkac943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/16/2022] [Accepted: 10/15/2022] [Indexed: 12/05/2022] Open
Abstract
Mammalian cells immediately inhibit transcription upon exposure to genotoxic stress to avoid fatal collision between ongoing transcription and newly recruited DNA repair machineries to protect genomic integrity. However, mechanisms of this early transcriptional inhibition are poorly understood. In this study, we decipher a novel role of human EAF1, a positive regulator of ELL-dependent RNA Polymerase II-mediated transcription in vitro, in regulation of temporal inhibition of transcription during genotoxic stress. Our results show that, besides Super Elongation Complex (SEC) and Little Elongation Complex (LEC), human ELL (aka ELL1) also forms a complex with EAF1 alone. Interestingly, contrary to the in vitro studies, EAF1 inhibits ELL-dependent RNA polymerase II-mediated transcription of diverse target genes. Mechanistically, we show that intrinsic self-association property of ELL leads to its reduced interaction with other SEC components. EAF1 enhances ELL self-association and thus reduces its interaction with other SEC components leading to transcriptional inhibition. Physiologically, we show that upon exposure to genotoxic stress, ATM-mediated ELL phosphorylation-dependent enhanced EAF1 association results in reduced ELL interaction with other SEC components that lead to global transcriptional inhibition. Thus, we describe an important mechanism of dynamic transcriptional regulation during genotoxic stress involving post-translational modification of a key elongation factor.
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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
| | - Dipika Yadav
- Laboratory of Transcription Biology, Molecular Genetics Division, CSIR-Indian Institute of Chemical Biology , 4, Raja S. C. Mullick Road , Kolkata - 32, 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
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PARP1′s Involvement in RNA Polymerase II Elongation: Pausing and Releasing Regulation through the Integrator and Super Elongation Complex. Cells 2022; 11:cells11203202. [PMID: 36291070 PMCID: PMC9600911 DOI: 10.3390/cells11203202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/07/2022] [Accepted: 10/08/2022] [Indexed: 11/17/2022] Open
Abstract
RNA polymerase elongation along the gene body is tightly regulated to ensure proper transcription and alternative splicing events. Understanding the mechanism and factors critical in regulating the rate of RNA polymerase II elongation and processivity is clearly important. Recently we showed that PARP1, a well-known DNA repair protein, when bound to chromatin, regulates RNA polymerase II elongation. However, the mechanism by which it does so is not known. In the current study, we aimed to tease out how PARP1 regulates RNAPII elongation. We show, both in vivo and in vitro, that PARP1 binds directly to the Integrator subunit 3 (IntS3), a member of the elongation Integrator complex. The association between the two proteins is mediated via the C-terminal domain of PARP1 to the C-terminal domain of IntS3. Interestingly, the occupancy of IntS3 along two PARP1 target genes mimicked that of PARP1, suggesting a role in its recruitment/assembly of elongation factors. Indeed, the knockdown of PARP1 resulted in differential chromatin association and gene occupancy of IntS3 and other key elongation factors. Most of these PARP1-mediated effects were due to the physical presence of PARP1 rather than its PARylation activity. These studies argue that PARP1 controls the progressive RNAPII elongation complexes. In summary, we present a platform to begin to decipher PARP1′s role in recruiting/scaffolding elongation factors along the gene body regions during RNA polymerase II elongation and gene regulation.
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46
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Song A, Chen FX. The pleiotropic roles of SPT5 in transcription. Transcription 2022; 13:53-69. [PMID: 35876486 PMCID: PMC9467590 DOI: 10.1080/21541264.2022.2103366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Initially discovered by genetic screens in budding yeast, SPT5 and its partner SPT4 form a stable complex known as DSIF in metazoa, which plays pleiotropic roles in multiple steps of transcription. SPT5 is the most conserved transcription elongation factor, being found in all three domains of life; however, its structure has evolved to include new domains and associated posttranslational modifications. These gained features have expanded transcriptional functions of SPT5, likely to meet the demand for increasingly complex regulation of transcription in higher organisms. This review discusses the pleiotropic roles of SPT5 in transcription, including RNA polymerase II (Pol II) stabilization, enhancer activation, Pol II pausing and its release, elongation, and termination, with a focus on the most recent progress of SPT5 functions in regulating metazoan transcription.
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Affiliation(s)
- Aixia Song
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
| | - Fei Xavier Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
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47
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Dai SK, Liu PP, Li X, Jiao LF, Teng ZQ, Liu CM. Dynamic profiling and functional interpretation of histone lysine crotonylation and lactylation during neural development. Development 2022; 149:276044. [DOI: 10.1242/dev.200049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 06/16/2022] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Metabolites such as crotonyl-CoA and lactyl-CoA influence gene expression by covalently modifying histones, known as histone lysine crotonylation (Kcr) and lysine lactylation (Kla). However, the existence patterns, dynamic changes, biological functions and associations of these modifications with histone lysine acetylation and gene expression during mammalian development remain largely unknown. Here, we find that histone Kcr and Kla are widely distributed in the brain and undergo global changes during neural development. By profiling the genome-wide dynamics of H3K9ac, H3K9cr and H3K18la in combination with ATAC and RNA sequencing, we reveal that these marks are tightly correlated with chromatin state and gene expression, and extensively involved in transcriptome remodeling to promote cell-fate transitions in the developing telencephalon. Importantly, we demonstrate that global Kcr and Kla levels are not the consequence of transcription and identify the histone deacetylases (HDACs) 1-3 as novel ‘erasers’ of H3K18la. Using P19 cells as an induced neural differentiation system, we find that HDAC1-3 inhibition by MS-275 pre-activates neuronal transcriptional programs by stimulating multiple histone lysine acylations simultaneously. These findings suggest that histone Kcr and Kla play crucial roles in the epigenetic regulation of neural development.
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Affiliation(s)
- Shang-Kun Dai
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences 1 , Beijing 100101 , China
- Savaid Medical School, University of Chinese Academy of Sciences 2 , Beijing 100049 , China
- School of Life Sciences and Medicine, Shandong University of Technology 3 , Zibo 255049 , China
| | - Pei-Pei Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences 1 , Beijing 100101 , China
- Savaid Medical School, University of Chinese Academy of Sciences 2 , Beijing 100049 , China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences 4 , Beijing 100101 , China
- Beijing Institute for Stem Cell and Regenerative Medicine 5 , Beijing 100101 , China
| | - Xiao Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences 1 , Beijing 100101 , China
- Savaid Medical School, University of Chinese Academy of Sciences 2 , Beijing 100049 , China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences 4 , Beijing 100101 , China
- Beijing Institute for Stem Cell and Regenerative Medicine 5 , Beijing 100101 , China
| | - Lin-Fei Jiao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences 1 , Beijing 100101 , China
- Savaid Medical School, University of Chinese Academy of Sciences 2 , Beijing 100049 , China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences 4 , Beijing 100101 , China
- Beijing Institute for Stem Cell and Regenerative Medicine 5 , Beijing 100101 , China
| | - Zhao-Qian Teng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences 1 , Beijing 100101 , China
- Savaid Medical School, University of Chinese Academy of Sciences 2 , Beijing 100049 , China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences 4 , Beijing 100101 , China
- Beijing Institute for Stem Cell and Regenerative Medicine 5 , Beijing 100101 , China
| | - Chang-Mei Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences 1 , Beijing 100101 , China
- Savaid Medical School, University of Chinese Academy of Sciences 2 , Beijing 100049 , China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences 4 , Beijing 100101 , China
- Beijing Institute for Stem Cell and Regenerative Medicine 5 , Beijing 100101 , China
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Morgan M, Shiekhattar R, Shilatifard A, Lauberth SM. It's a DoG-eat-DoG world-altered transcriptional mechanisms drive downstream-of-gene (DoG) transcript production. Mol Cell 2022; 82:1981-1991. [PMID: 35487209 PMCID: PMC9208299 DOI: 10.1016/j.molcel.2022.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/24/2022] [Accepted: 04/04/2022] [Indexed: 10/18/2022]
Abstract
The past decade has revolutionized our understanding of regulatory noncoding RNAs (ncRNAs). Among the most recently identified ncRNAs are downstream-of-gene (DoG)-containing transcripts that are produced by widespread transcriptional readthrough. The discovery of DoGs has set the stage for future studies to address many unanswered questions regarding the mechanisms that promote readthrough transcription, RNA processing, and the cellular functions of the unique transcripts. In this review, we summarize current findings regarding the biogenesis, function, and mechanisms regulating this exciting new class of RNA molecules.
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Affiliation(s)
- Marc Morgan
- Simpson Querrey Institute for Epigenetics and Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ramin Shiekhattar
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ali Shilatifard
- Simpson Querrey Institute for Epigenetics and Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Shannon M Lauberth
- Simpson Querrey Institute for Epigenetics and Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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49
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Gray JS, Wani SA, Campbell MJ. Epigenomic alterations in cancer: mechanisms and therapeutic potential. Clin Sci (Lond) 2022; 136:473-492. [PMID: 35383835 DOI: 10.1042/cs20210449] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 11/17/2022]
Abstract
The human cell requires ways to specify its transcriptome without altering the essential sequence of DNA; this is achieved through mechanisms which govern the epigenetic state of DNA and epitranscriptomic state of RNA. These alterations can be found as modified histone proteins, cytosine DNA methylation, non-coding RNAs, and mRNA modifications, such as N6-methyladenosine (m6A). The different aspects of epigenomic and epitranscriptomic modifications require protein complexes to write, read, and erase these chemical alterations. Reflecting these important roles, many of these reader/writer/eraser proteins are either frequently mutated or differentially expressed in cancer. The disruption of epigenetic regulation in the cell can both contribute to cancer initiation and progression, and increase the likelihood of developing resistance to chemotherapies. Development of therapeutics to target proteins involved in epigenomic/epitranscriptomic modifications has been intensive, but further refinement is necessary to achieve ideal treatment outcomes without too many off-target effects for cancer patients. Therefore, further integration of clinical outcomes combined with large-scale genomic analyses is imperative for furthering understanding of epigenomic mechanisms in cancer.
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Affiliation(s)
- Jaimie S Gray
- Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Sajad A Wani
- Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Moray J Campbell
- Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210, U.S.A
- Biomedical Informatics Shared Resource, The Ohio State University, Columbus, OH 43210, U.S.A
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50
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Abu-Zhayia ER, Bishara LA, Machour FE, Barisaac AS, Ben-Oz BM, Ayoub N. CDYL1-dependent decrease in lysine crotonylation at DNA double-strand break sites functionally uncouples transcriptional silencing and repair. Mol Cell 2022; 82:1940-1955.e7. [PMID: 35447080 DOI: 10.1016/j.molcel.2022.03.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 01/17/2022] [Accepted: 03/23/2022] [Indexed: 11/16/2022]
Abstract
Previously, we showed that CDYL1 is recruited to DNA double-strand breaks (DSBs) to promote homologous recombination (HR) repair and foster transcriptional silencing. However, how CDYL1 elicits DSB-induced silencing is not fully understood. Here, we identify a CDYL1-dependent local decrease in the transcriptionally active marks histone lysine crotonylation (Kcr) and crotonylated lysine 9 of H3 (H3K9cr) at AsiSI-induced DSBs, which correlates with transcriptional silencing. Mechanistically, we reveal that CDYL1 crotonyl-CoA hydratase activity counteracts Kcr and H3K9cr at DSB sites, which triggers the eviction of the transcription elongation factor ENL and fosters transcriptional silencing. Furthermore, genetic inhibition of CDYL1 hydratase activity blocks the reduction in H3K9cr and alleviates DSB-induced silencing, whereas HR efficiency unexpectedly remains intact. Therefore, our results functionally uncouple the repair and silencing activity of CDYL1 at DSBs. In a broader context, we address a long-standing question concerning the functional relationship between HR repair and DSB-induced silencing, suggesting that they may occur independently.
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Affiliation(s)
- Enas R Abu-Zhayia
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Laila A Bishara
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Feras E Machour
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Alma Sophia Barisaac
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Bella M Ben-Oz
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Nabieh Ayoub
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
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