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Gillis A, Berry S. Global control of RNA polymerase II. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2024; 1867:195024. [PMID: 38552781 DOI: 10.1016/j.bbagrm.2024.195024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/11/2024]
Abstract
RNA polymerase II (Pol II) is the multi-protein complex responsible for transcribing all protein-coding messenger RNA (mRNA). Most research on gene regulation is focused on the mechanisms controlling which genes are transcribed when, or on the mechanics of transcription. How global Pol II activity is determined receives comparatively less attention. Here, we follow the life of a Pol II molecule from 'assembly of the complex' to nuclear import, enzymatic activity, and degradation. We focus on how Pol II spends its time in the nucleus, and on the two-way relationship between Pol II abundance and activity in the context of homeostasis and global transcriptional changes.
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Affiliation(s)
- Alexander Gillis
- EMBL Australia Node in Single Molecule Science, University of New South Wales, Sydney, Australia; UNSW RNA Institute, University of New South Wales, Sydney, Australia; Department of Molecular Medicine, School of Biomedical Sciences, University of New South Wales, Sydney, Australia
| | - Scott Berry
- EMBL Australia Node in Single Molecule Science, University of New South Wales, Sydney, Australia; UNSW RNA Institute, University of New South Wales, Sydney, Australia; Department of Molecular Medicine, School of Biomedical Sciences, University of New South Wales, Sydney, Australia
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2
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Zhang Z, Xu J, Liu J, Wang J, Lei L. SEC: A core hub during cell fate alteration. FASEB J 2024; 38:e23680. [PMID: 38758186 DOI: 10.1096/fj.202400514r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/18/2024] [Accepted: 05/07/2024] [Indexed: 05/18/2024]
Abstract
Pol II pause release is a rate-limiting step in gene transcription, influencing various cell fate alterations. Numerous proteins orchestrate Pol II pause release, thereby playing pivotal roles in the intricate process of cellular fate modulation. Super elongation complex (SEC), a large assembly comprising diverse protein components, has garnered attention due to its emerging significance in orchestrating physiological and pathological cellular identity changes by regulating the transcription of crucial genes. Consequently, SEC emerges as a noteworthy functional complex capable of modulating cell fate alterations. Therefore, a comprehensive review is warranted to systematically summarize the core roles of SEC in different types of cell fate alterations. This review focuses on elucidating the current understanding of the structural and functional basis of SEC. Additionally, we discuss the intricate regulatory mechanisms governing SEC in various models of cell fate alteration, encompassing both physiological and pathological contexts. Furthermore, leveraging the existing knowledge of SEC, we propose some insightful directions for future research, aiming to enhance our mechanistic and functional comprehension of SEC within the diverse landscape of cell fate alterations.
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Affiliation(s)
- Zhijing Zhang
- College of Life Science, Northeast Agricultural University, Harbin, Heilongjiang Province, China
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jingyi Xu
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jiqiang Liu
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jiaqiang Wang
- College of Life Science, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - Lei Lei
- Department of Histology and Embryology, Harbin Medical University, Harbin, Heilongjiang Province, China
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3
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Walker FM, Sobral LM, Danis E, Sanford B, Donthula S, Balakrishnan I, Wang D, Pierce A, Karam SD, Kargar S, Serkova NJ, Foreman NK, Venkataraman S, Dowell R, Vibhakar R, Dahl NA. Rapid P-TEFb-dependent transcriptional reorganization underpins the glioma adaptive response to radiotherapy. Nat Commun 2024; 15:4616. [PMID: 38816355 DOI: 10.1038/s41467-024-48214-3] [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: 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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Du X, Qin W, Yang C, Dai L, San M, Xia Y, Zhou S, Wang M, Wu S, Zhang S, Zhou H, Li F, He F, Tang J, Chen JY, Zhou Y, Xiao R. RBM22 regulates RNA polymerase II 5' pausing, elongation rate, and termination by coordinating 7SK-P-TEFb complex and SPT5. Genome Biol 2024; 25:102. [PMID: 38641822 PMCID: PMC11027413 DOI: 10.1186/s13059-024-03242-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 04/09/2024] [Indexed: 04/21/2024] Open
Abstract
BACKGROUND Splicing factors are vital for the regulation of RNA splicing, but some have also been implicated in regulating transcription. The underlying molecular mechanisms of their involvement in transcriptional processes remain poorly understood. RESULTS Here, we describe a direct role of splicing factor RBM22 in coordinating multiple steps of RNA Polymerase II (RNAPII) transcription in human cells. The RBM22 protein widely occupies the RNAPII-transcribed gene locus in the nucleus. Loss of RBM22 promotes RNAPII pause release, reduces elongation velocity, and provokes transcriptional readthrough genome-wide, coupled with production of transcripts containing sequences from downstream of the gene. RBM22 preferentially binds to the hyperphosphorylated, transcriptionally engaged RNAPII and coordinates its dynamics by regulating the homeostasis of the 7SK-P-TEFb complex and the association between RNAPII and SPT5 at the chromatin level. CONCLUSIONS Our results uncover the multifaceted role of RBM22 in orchestrating the transcriptional program of RNAPII and provide evidence implicating a splicing factor in both RNAPII elongation kinetics and termination control.
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Affiliation(s)
- Xian Du
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Wenying Qin
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Chunyu Yang
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Lin Dai
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Mingkui San
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Yingdan Xia
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Siyu Zhou
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Mengyang Wang
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Shuang Wu
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Shaorui Zhang
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Huiting Zhou
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Fangshu Li
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Fang He
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
| | - Jingfeng Tang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, School of Life and Health Sciences, Hubei University of Technology, Wuhan, China
| | - Jia-Yu Chen
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing, China
| | - Yu Zhou
- TaiKang Center for Life and Medical Sciences, College of Life Sciences, State Key Laboratory of Virology, Wuhan University, Wuhan, China
| | - Rui Xiao
- Department of Hematology, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China.
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China.
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Santana JF, Spector BM, Suarez G, Luse D, Price D. NELF focuses sites of initiation and maintains promoter architecture. Nucleic Acids Res 2024; 52:2977-2994. [PMID: 38197272 PMCID: PMC11014283 DOI: 10.1093/nar/gkad1253] [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: 09/26/2023] [Revised: 11/29/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024] Open
Abstract
Many factors control the elongation phase of transcription by RNA polymerase II (Pol II), a process that plays an essential role in regulating gene expression. We utilized cells expressing degradation tagged subunits of NELFB, PAF1 and RTF1 to probe the effects of depletion of the factors on nascent transcripts using PRO-Seq and on chromatin architecture using DFF-ChIP. Although NELF is involved in promoter proximal pausing, depletion of NELFB had only a minimal effect on the level of paused transcripts and almost no effect on control of productive elongation. Instead, NELF depletion increased the utilization of downstream transcription start sites and caused a dramatic, genome-wide loss of H3K4me3 marked nucleosomes. Depletion of PAF1 and RTF1 both had major effects on productive transcript elongation in gene bodies and also caused initiation site changes like those seen with NELFB depletion. Our study confirmed that the first nucleosome encountered during initiation and early elongation is highly positioned with respect to the major TSS. In contrast, the positions of H3K4me3 marked nucleosomes in promoter regions are heterogeneous and are influenced by transcription. We propose a model defining NELF function and a general role of the H3K4me3 modification in blocking transcription initiation.
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Affiliation(s)
- Juan F Santana
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Benjamin M Spector
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Gustavo A Suarez
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Donal S Luse
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - David H Price
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
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6
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Kyheröinen S, Prajapati B, Sokolova M, Schmitz M, Viita T, Geyer M, Vartiainen MK. Actin associates with actively elongating genes and binds directly to the Cdk9 subunit of P-TEFb. J Biol Chem 2024; 300:105698. [PMID: 38301887 PMCID: PMC10891344 DOI: 10.1016/j.jbc.2024.105698] [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: 11/15/2023] [Revised: 01/08/2024] [Accepted: 01/21/2024] [Indexed: 02/03/2024] Open
Abstract
Nuclear actin has been demonstrated to be essential for optimal transcription, but the molecular mechanisms and direct binding partner for actin in the RNA polymerase complex have remained unknown. By using purified proteins in a variety of biochemical assays, we demonstrate a direct and specific interaction between monomeric actin and Cdk9, the kinase subunit of the positive transcription elongation factor b required for RNA polymerase II pause-release. This interaction efficiently prevents actin polymerization, is not dependent on kinase activity of Cdk9, and is not involved with releasing positive transcription elongation factor b from its inhibitor 7SK snRNP complex. Supporting the specific role for actin in the elongation phase of transcription, chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) reveals that actin interacts with genes only upon their active transcription elongation. This study therefore provides novel insights into the mechanisms by which actin facilitates the transcription process.
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Affiliation(s)
- Salla Kyheröinen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Bina Prajapati
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Maria Sokolova
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | | | - Tiina Viita
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Maria K Vartiainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
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7
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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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8
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Lu F, Park BJ, Fujiwara R, Wilusz JE, Gilmour DS, Lehmann R, Lionnet T. Integrator-mediated clustering of poised RNA polymerase II synchronizes histone transcription. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.07.561364. [PMID: 37873455 PMCID: PMC10592978 DOI: 10.1101/2023.10.07.561364] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Numerous components of the transcription machinery, including RNA polymerase II (Pol II), accumulate in regions of high local concentration known as clusters, which are thought to facilitate transcription. Using the histone locus of Drosophila nurse cells as a model, we find that Pol II forms long-lived, transcriptionally poised clusters distinct from liquid droplets, which contain unbound and paused Pol II. Depletion of the Integrator complex endonuclease module, but not its phosphatase module or Pol II pausing factors disperses these Pol II clusters. Consequently, histone transcription fails to reach peak levels during S-phase and aberrantly continues throughout the cell cycle. We propose that Pol II clustering is a regulatory step occurring near promoters that limits rapid gene activation to defined times. One Sentence Summary Using the Drosophila histone locus as a model, we show that clustered RNA polymerase II is poised for synchronous activation.
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9
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Palumbo RJ, Yang Y, Feigon J, Hanes SD. Catalytic activity of the Bin3/MePCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. Genetics 2024; 226:iyad203. [PMID: 37982586 PMCID: PMC10763541 DOI: 10.1093/genetics/iyad203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/27/2023] [Accepted: 11/13/2023] [Indexed: 11/21/2023] Open
Abstract
Methylphosphate Capping Enzyme (MePCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MePCE in vitro, little is known about its functions in vivo, or what roles-if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MePCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MePCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MePCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Yuan Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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10
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Schmitz M, Kaltheuner IH, Anand K, Düster R, Moecking J, Monastyrskyi A, Duckett DR, Roush WR, Geyer M. The reversible inhibitor SR-4835 binds Cdk12/cyclin K in a noncanonical G-loop conformation. J Biol Chem 2024; 300:105501. [PMID: 38016516 PMCID: PMC10767194 DOI: 10.1016/j.jbc.2023.105501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/23/2023] [Accepted: 11/08/2023] [Indexed: 11/30/2023] Open
Abstract
Inhibition of cyclin-dependent kinases (CDKs) has evolved as an emerging anticancer strategy. In addition to the cell cycle-regulating CDKs, the transcriptional kinases Cdk12 and Cdk13 have become the focus of interest as they mediate a variety of functions, including the transition from transcription initiation to elongation and termination, precursor mRNA splicing, and intronic polyadenylation. Here, we determine the crystal structure of the small molecular inhibitor SR-4835 bound to the Cdk12/cyclin K complex at 2.68 Å resolution. The compound's benzimidazole moiety is embedded in a unique hydrogen bond network mediated by the kinase hinge region with flanking hydroxy groups of the Y815 and D819 side chains. Whereas the SR-4835 head group targets the adenine-binding pocket, the kinase's glycine-rich loop is shifted down toward the activation loop. Additionally, the αC-helix adopts an inward conformation, and the phosphorylated T-loop threonine interacts with all three canonical arginines, a hallmark of CDK activation that is altered in Cdk12 and Cdk13. Dose-response inhibition measurements with recombinant CMGC kinases show that SR-4835 is highly specific for Cdk12 and Cdk13 following a 10-fold lower potency for Cdk10. Whereas other CDK-targeting compounds exhibit tighter binding affinities and higher potencies for kinase inhibition, SR-4835 can be considered a selective transcription elongation antagonist. Our results provide the basis for a rational improvement of SR-4835 toward Cdk12 inhibition and a gain in selectivity over other transcription regulating CDKs.
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Affiliation(s)
| | | | - Kanchan Anand
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Robert Düster
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Jonas Moecking
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | | | - Derek R Duckett
- Department of Drug Discovery, Moffitt Cancer Center, Tampa, Florida, USA
| | - William R Roush
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida, USA
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Bonn, Germany.
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11
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Nandy A, Biswas D. Basic techniques associated with studying transcription elongation both in vitro and in vivo within mammalian cells. Methods 2024; 221:42-54. [PMID: 38040206 DOI: 10.1016/j.ymeth.2023.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/23/2023] [Accepted: 11/28/2023] [Indexed: 12/03/2023] Open
Abstract
All cellular functions and identity of every cell are directly or indirectly depend on its gene expression. Therefore, cells control their gene expression very finely at multiple layers. Cells always fine tune its gene expression profile depending on the internal and external cues to maintain best possible cellular growth condition. Regulation of mRNA production is a major step in the control of gene expression. mRNA production primarily depends on two factors. One is the level of RNA polymerase II (Pol II hereafter) recruitment at the promoter region and another is the amount of Pol II successfully elongating through the whole gene body also known as coding region. There are several proteins (individually or as part of a complex) which control elongation of Pol II both positively or negatively. It is important to understand how different transcription factors regulate this elongation step since this knowledge is important for understanding different cellular functions both under basal and stimulus-dependent contexts. Here, we have discussed both in vitro and in vivo techniques which can be used to study the effect of different factors on Pol II-mediated transcription elongation. In vitro techniques give us valuable information about the ability of a transcription factor or a complex to exert its direct effect on the overall processes. In vivo techniques give us an understanding about the effect of a transcription factor or a complex in its native condition where functions of a transcription factor can be influenced by many other factors including its associated ones.
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Affiliation(s)
- Arijit Nandy
- 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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12
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Cornejo KG, Venegas A, Sono MH, Door M, Gutierrez-Ruiz B, Karabedian LB, Nandi SG, Dykhuizen EC, Saha RN. Activity-assembled nBAF complex mediates rapid immediate early gene transcription by regulating RNA Polymerase II productive elongation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.30.573688. [PMID: 38234780 PMCID: PMC10793463 DOI: 10.1101/2023.12.30.573688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Signal-dependent RNA Polymerase II (Pol2) productive elongation is an integral component of gene transcription, including those of immediate early genes (IEGs) induced by neuronal activity. However, it remains unclear how productively elongating Pol2 overcome nucleosomal barriers. Using RNAi, three degraders, and several small molecule inhibitors, we show that the mammalian SWI/SNF complex of neurons (neuronal BAF, or nBAF) is required for activity-induced transcription of neuronal IEGs, including Arc . The nBAF complex facilitates promoter-proximal Pol2 pausing, signal-dependent Pol2 recruitment (loading), and importantly, mediates productive elongation in the gene body via interaction with the elongation complex and elongation-competent Pol2. Mechanistically, Pol2 elongation is mediated by activity-induced nBAF assembly (especially, ARID1A recruitment) and its ATPase activity. Together, our data demonstrate that the nBAF complex regulates several aspects of Pol2 transcription and reveal mechanisms underlying activity-induced Pol2 elongation. These findings may offer insights into human maladies etiologically associated with mutational interdiction of BAF functions.
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13
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Minisini M, Cricchi E, Brancolini C. Acetylation and Phosphorylation in the Regulation of Hypoxia-Inducible Factor Activities: Additional Options to Modulate Adaptations to Changes in Oxygen Levels. Life (Basel) 2023; 14:20. [PMID: 38276269 PMCID: PMC10821055 DOI: 10.3390/life14010020] [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: 12/05/2023] [Revised: 12/13/2023] [Accepted: 12/20/2023] [Indexed: 01/27/2024] Open
Abstract
O2 is essential for the life of eukaryotic cells. The ability to sense oxygen availability and initiate a response to adapt the cell to changes in O2 levels is a fundamental achievement of evolution. The key switch for adaptation consists of the transcription factors HIF1A, HIF2A and HIF3A. Their levels are tightly controlled by O2 through the involvement of the oxygen-dependent prolyl hydroxylase domain-containing enzymes (PHDs/EGNLs), the von Hippel-Lindau tumour suppressor protein (pVHL) and the ubiquitin-proteasome system. Furthermore, HIF1A and HIF2A are also under the control of additional post-translational modifications (PTMs) that positively or negatively regulate the activities of these transcription factors. This review focuses mainly on two PTMs of HIF1A and HIF2A: phosphorylation and acetylation.
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Affiliation(s)
| | | | - Claudio Brancolini
- Lab of Epigenomics, Department of Medicine, Università degli Studi di Udine, 33100 Udine, Italy; (M.M.); (E.C.)
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14
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Gao G, Li J, Cao Y, Li X, Qian Y, Wang X, Li M, Qiu Y, Wu T, Wang L, Fang M. Design, synthesis, and biological evaluation of novel 4,4'-bipyridine derivatives acting as CDK9-Cyclin T1 protein-protein interaction inhibitors against triple-negative breast cancer. Eur J Med Chem 2023; 261:115858. [PMID: 37837671 DOI: 10.1016/j.ejmech.2023.115858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 09/25/2023] [Accepted: 10/05/2023] [Indexed: 10/16/2023]
Abstract
Cyclin-dependent kinase 9 (CDK9) is directly related to tumor development in triple-negative breast cancer (TNBC) patients. Increased CDK9 is significantly associated with poor patient prognosis, while inhibiting CDK9-Cyclin T1 protein-protein interaction has recently been demonstrated as a new approach to TNBC treatment. Herein, we synthesized a novel class of 4,4'-bipyridine derivatives as potential CDK9-Cyclin T1 PPI inhibitors against TNBC. The represented compound B19 was found to be an excellent and selective CDK9-Cyclin T1 PPI inhibitor with good potency against TNBC cell lines while exhibiting lower toxicity in normal human cell lines than the positive compound I-CDK9. Notably, compound B19 showed good pharmacokinetic properties and excellent antitumor activity against TNBC (4T1) allografts in mice with a therapeutic index of more than 42 (TGI4T1(12.5 mg/kg,i.p.) = 63.1% vs. LD50 = 537 mg/kg). Moreover, the administration of B19 in combination with the PARP inhibitor Olaparib results in a significant increase of the antitumor activity in MDA-MB-231 cells relative to that of either single agent. To our knowledge, B19 is the first reported non-metal organic compound that acts as a selective CDK9-Cyclin T1 PPI inhibitor with in vivo antitumor activity, and it may be alone and in combination with PARP inhibitor Olaparib for TNBC therapy.
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Affiliation(s)
- Guiping Gao
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China; Huaqiao University School of Medicine Science, Quanzhou, 362021, China
| | - Jiayi Li
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China
| | - Yin Cao
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China
| | - Xudan Li
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China
| | - Yuqing Qian
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China; School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330006, PR China
| | - Xiumei Wang
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China
| | - Mengyu Li
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China
| | - Yingkun Qiu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China
| | - Tong Wu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China.
| | - Liqiang Wang
- Huaqiao University School of Medicine Science, Quanzhou, 362021, China.
| | - Meijuan Fang
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Science, Xiamen University, Xiamen, 361102, China.
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15
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Zou H, Zhang B, Liang H, Li C, Chen J, Wu Y. Defence mechanisms of Pinctada fucata martensii to Vibrio parahaemolyticus infection: Insights from proteomics and metabolomics. FISH & SHELLFISH IMMUNOLOGY 2023; 143:109204. [PMID: 37931889 DOI: 10.1016/j.fsi.2023.109204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/28/2023] [Accepted: 10/30/2023] [Indexed: 11/08/2023]
Abstract
Survival of pearl oysters is not only challenged by coastal pollution, but also pathogen infection that may eventually incur substantial economic losses in the pearl farming industry. Yet, whether pearl oysters can defend themselves against pathogen infection through molecular mechanisms remains largely unexplored. By using iTRAQ proteomic and metabolomic analyses, we analysed the proteins and metabolites in the serum of pearl oysters (Pinctada fucata martensii) when stimulated by pathogenic bacteria (Vibrio parahaemolyticus). Proteomic results found that a total of 2,242 proteins were identified in the experimental (i.e., Vibrio-stimulated) and control groups, where 166 of them were differentially expressed (120 upregulated and 46 downregulated in the experimental group). Regarding the immune response enrichment results, the pathway of signal transduction was significantly enriched, such as cytoskeleton and calcium signalling pathways. Proteins, including cathepsin L, heat shock protein 20, myosin and astacin-like protein, also contributed to the immune response of oysters. Pathogen stimulation also altered the metabolite profile of oysters, where 49 metabolites associated with metabolism of energy, fatty acids and amino acids were found. Integrated analysis suggests that the oysters could respond to pathogen infection by coordinating multiple cellular processes. Thus, the proteins and metabolites identified herein not only represent valuable genetic resources for developing molecular biomarkers and genetic breeding research, but also open new avenues for studies on the molecular defence mechanisms of pearl oysters to pathogen infection.
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Affiliation(s)
- Hexin Zou
- Fisheries College of Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Bin Zhang
- Fisheries College of Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Haiying Liang
- Fisheries College of Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China; Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Zhanjiang, Guangdong, 524088, China.
| | - Chaojie Li
- Fisheries College of Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Jie Chen
- Fisheries College of Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Yifan Wu
- Fisheries College of Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
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16
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Kuang Z, Guo K, Cao Y, Jiang M, Wang C, Wu Q, Hu G, Ao M, Huang M, Qin J, Zhao T, Lu S, Sun C, Li M, Wu T, Liu W, Fang M. The novel CDK9 inhibitor, XPW1, alone and in combination with BRD4 inhibitor JQ1, for the treatment of clear cell renal cell carcinoma. Br J Cancer 2023; 129:1915-1929. [PMID: 37884683 PMCID: PMC10703862 DOI: 10.1038/s41416-023-02464-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 09/22/2023] [Accepted: 10/04/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Clear cell renal cell carcinoma (ccRCC) is a highly lethal malignancy with few therapeutic options. Cyclin‑dependent kinase 9 (CDK9), a potential therapeutic target of many cancers, has been recently observed to be upregulated in ccRCC patients. Therefore, we aimed to investigate the therapeutic potential of CDK9 in ccRCC and develop a novel CDK9 inhibitor with low toxicity for ccRCC treatment. METHODS The expression of CDK9 in ccRCC was checked using the online database and tissue microarray analysis. shRNA-mediated CDK9 knockdown and CDK inhibitor were applied to evaluate the effect of CDK9 on ccRCC. Medicinal chemistry methods were used to develop a new CDK9 inhibitor with drugability. RNA-seq and ChIP-seq experiments were conducted to explore the mechanism of action. MTS, western blotting, and colony formation assays were performed to evaluate the anti-ccRCC effects of CDK9 knockdown and inhibition in vitro. The in vivo anti-tumour efficacy was evaluated in a xenograft model. RESULTS CDK9 is overexpressed and associated with poor survival in ccRCC. Knockdown or inhibition of CDK9 significantly suppressed ccRCC cells. XPW1 was identified as a new potent and selective CDK9 inhibitor with excellent anti-ccRCC activity and low toxicity. In mechanism, XPW1 transcriptionally inhibited DNA repair programmes in ccRCC cells, resulting in an excellent anti-tumour effect. CDK9 and BRD4 were two highly correlated transcriptional regulators in ccRCC patients, and the BRD4 inhibitor JQ1 enhanced XPW1's anti-ccRCC effects in vitro and in vivo. CONCLUSIONS This work provides valuable insights into the therapeutic potential of CDK9 in ccRCC. The CDK9 inhibitor XPW1 would be a novel therapeutic agent for targeting ccRCC, alone or in rational combinations.
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Affiliation(s)
- Zhijian Kuang
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Kaiqiang Guo
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
- College of Arts, Sichuan University, 610207, Chengdu, China
| | - Yin Cao
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Mengxue Jiang
- School of Medicine, Xiamen University, 361102, Xiamen, China
| | - Chaojie Wang
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
- Jiangxi Cancer Hospital (The Second Affiliated Hospital of Nanchang Medical Colloge), 519 East Beijing Rd, 330029, Nanchang, Jiangxi, China
| | - Qiaoqiong Wu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Guosheng Hu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Mingtao Ao
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Mingfeng Huang
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Jingbo Qin
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Taige Zhao
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Sheng Lu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Cuiling Sun
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Mingyu Li
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China
| | - Tong Wu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China.
| | - Wen Liu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China.
| | - Meijuan Fang
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, 361102, Xiamen, China.
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17
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Hasterok S, Scott TG, Roller DG, Spencer A, Dutta AB, Sathyan KM, Frigo DE, Guertin MJ, Gioeli D. The Androgen Receptor Does Not Directly Regulate the Transcription of DNA Damage Response Genes. Mol Cancer Res 2023; 21:1329-1341. [PMID: 37698543 PMCID: PMC11022999 DOI: 10.1158/1541-7786.mcr-23-0358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/02/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
The clinical success of combined androgen deprivation therapy (ADT) and radiotherapy (RT) in prostate cancer created interest in understanding the mechanistic links between androgen receptor (AR) signaling and the DNA damage response (DDR). Convergent data have led to a model where AR both regulates, and is regulated by, the DDR. Integral to this model is that the AR regulates the transcription of DDR genes both at a steady state and in response to ionizing radiation (IR). In this study, we sought to determine which immediate transcriptional changes are induced by IR in an AR-dependent manner. Using PRO-seq to quantify changes in nascent RNA transcription in response to IR, the AR antagonist enzalutamide, or the combination of the two, we find that enzalutamide treatment significantly decreased expression of canonical AR target genes but had no effect on DDR gene sets in prostate cancer cells. Surprisingly, we also found that the AR is not a primary regulator of DDR genes either in response to IR or at a steady state in asynchronously growing prostate cancer cells. IMPLICATIONS Our data indicate that the clinical benefit of combining ADT with RT is not due to direct AR regulation of DDR gene transcription, and that the field needs to consider alternative mechanisms for this clinical benefit.
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Affiliation(s)
- Sylwia Hasterok
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Thomas G. Scott
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA
| | - Devin G. Roller
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Adam Spencer
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Arun B. Dutta
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA
| | - Kizhakke M Sathyan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut, Farmington, Connecticut 06030, USA
| | - Daniel E. Frigo
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Genitourinary Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX, USA
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Michael J. Guertin
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut, Farmington, Connecticut 06030, USA
- Department of Genetics and Genome Sciences, University of Connecticut, Farmington, Connecticut 06030, USA
| | - Daniel Gioeli
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
- Cancer Center Member, University of Virginia, Charlottesville, Virginia, USA
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18
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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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19
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Wang Z, Himanen SV, Haikala HM, Friedel CC, Vihervaara A, Barborič M. Inhibition of CDK12 elevates cancer cell dependence on P-TEFb by stimulation of RNA polymerase II pause release. Nucleic Acids Res 2023; 51:10970-10991. [PMID: 37811895 PMCID: PMC10639066 DOI: 10.1093/nar/gkad792] [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: 03/20/2023] [Revised: 09/11/2023] [Accepted: 09/22/2023] [Indexed: 10/10/2023] Open
Abstract
P-TEFb and CDK12 facilitate transcriptional elongation by RNA polymerase II. Given the prominence of both kinases in cancer, gaining a better understanding of their interplay could inform the design of novel anti-cancer strategies. While down-regulation of DNA repair genes in CDK12-targeted cancer cells is being explored therapeutically, little is known about mechanisms and significance of transcriptional induction upon inhibition of CDK12. We show that selective targeting of CDK12 in colon cancer-derived cells activates P-TEFb via its release from the inhibitory 7SK snRNP. In turn, P-TEFb stimulates Pol II pause release at thousands of genes, most of which become newly dependent on P-TEFb. Amongst the induced genes are those stimulated by hallmark pathways in cancer, including p53 and NF-κB. Consequently, CDK12-inhibited cancer cells exhibit hypersensitivity to inhibitors of P-TEFb. While blocking P-TEFb triggers their apoptosis in a p53-dependent manner, it impedes cell proliferation irrespective of p53 by preventing induction of genes downstream of the DNA damage-induced NF-κB signaling. In summary, stimulation of Pol II pause release at the signal-responsive genes underlies the functional dependence of CDK12-inhibited cancer cells on P-TEFb. Our study establishes the mechanistic underpinning for combinatorial targeting of CDK12 with either P-TEFb or the induced oncogenic pathways in cancer.
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Affiliation(s)
- Zhijia Wang
- Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Samu V Himanen
- Department of Gene Technology, KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Heidi M Haikala
- Translational Immunology Research Program (TRIMM), Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki FIN-00014, Finland
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Helsinki FIN-00014, Finland
| | - Caroline C Friedel
- Institute of Informatics, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - Anniina Vihervaara
- Department of Gene Technology, KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Matjaž Barborič
- Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
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20
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Huang J, Ji X. Never a dull enzyme, RNA polymerase II. Transcription 2023; 14:49-67. [PMID: 37132022 PMCID: PMC10353340 DOI: 10.1080/21541264.2023.2208023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/04/2023] Open
Abstract
RNA polymerase II (Pol II) is composed of 12 subunits that collaborate to synthesize mRNA within the nucleus. Pol II is widely recognized as a passive holoenzyme, with the molecular functions of its subunits largely ignored. Recent studies employing auxin-inducible degron (AID) and multi-omics techniques have revealed that the functional diversity of Pol II is achieved through the differential contributions of its subunits to various transcriptional and post-transcriptional processes. By regulating these processes in a coordinated manner through its subunits, Pol II can optimize its activity for diverse biological functions. Here, we review recent progress in understanding Pol II subunits and their dysregulation in diseases, Pol II heterogeneity, Pol II clusters and the regulatory roles of RNA polymerases.
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Affiliation(s)
- Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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21
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Langenbacher AD, Lu F, Tsang L, Huang ZYS, Keer B, Tian Z, Eide A, Pellegrini M, Nakano H, Nakano A, Chen JN. Rtf1-dependent transcriptional pausing regulates cardiogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.13.562296. [PMID: 37873297 PMCID: PMC10592831 DOI: 10.1101/2023.10.13.562296] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
During heart development, a well-characterized network of transcription factors initiates cardiac gene expression and defines the precise timing and location of cardiac progenitor specification. However, our understanding of the post-initiation transcriptional events that regulate cardiac gene expression is still incomplete. The PAF1C component Rtf1 is a transcription regulatory protein that modulates pausing and elongation of RNA Pol II, as well as cotranscriptional histone modifications. Here we report that Rtf1 is essential for cardiogenesis in fish and mammals, and that in the absence of Rtf1 activity, cardiac progenitors arrest in an immature state. We found that Rtf1's Plus3 domain, which confers interaction with the transcriptional pausing and elongation regulator Spt5, was necessary for cardiac progenitor formation. ChIP-seq analysis further revealed changes in the occupancy of RNA Pol II around the transcription start site (TSS) of cardiac genes in rtf1 morphants reflecting a reduction in transcriptional pausing. Intriguingly, inhibition of pause release in rtf1 morphants and mutants restored the formation of cardiac cells and improved Pol II occupancy at the TSS of key cardiac genes. Our findings highlight the crucial role that transcriptional pausing plays in promoting normal gene expression levels in a cardiac developmental context.
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Affiliation(s)
- Adam D. Langenbacher
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Fei Lu
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Luna Tsang
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Zi Yi Stephanie Huang
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Benjamin Keer
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Zhiyu Tian
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Alette Eide
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Matteo Pellegrini
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Haruko Nakano
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Atsushi Nakano
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Jau-Nian Chen
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
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22
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Kim J, Diaz LF, Miller MJ, Leadem B, Krivega I, Dean A. An enhancer RNA recruits MLL1 to regulate transcription of Myb. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.26.559528. [PMID: 37808852 PMCID: PMC10557664 DOI: 10.1101/2023.09.26.559528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The Myb proto-oncogene encodes the transcription factor c-MYB, which is critical for hematopoiesis. Distant enhancers of Myb form a hub of interactions with the Myb promoter. We identified a long non-coding RNA (Myrlin) originating from the -81 kb murine Myb enhancer. Myrlin and Myb are coordinately regulated during erythroid differentiation. Myrlin TSS deletion using CRISPR/Cas9 reduced Myrlin and Myb expression and LDB1 complex occupancy at the Myb enhancers, compromising enhancer contacts and reducing RNA Pol II occupancy in the locus. In contrast, CRISPRi silencing of Myrlin left LDB1 and the Myb enhancer hub unperturbed, although Myrlin and Myb expression were downregulated, decoupling transcription and chromatin looping. Myrlin interacts with the MLL1 complex. Myrlin CRISPRi compromised MLL1 occupancy in the Myb locus, decreasing CDK9 and RNA Pol II binding and resulting in Pol II pausing in the Myb first exon/intron. Thus, Myrlin directly participates in activating Myb transcription by recruiting MLL1.
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Affiliation(s)
- Juhyun Kim
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Luis F. Diaz
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Oregon Health and Sciences University, Portland, OR 97239
| | - Matthew J. Miller
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- University of Iowa Medical School, Iowa City, IA 52242
| | - Benjamin Leadem
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- GeneDx, Gaithersburg, MD 20877
| | - Ivan Krivega
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Sonothera, South San Francisco, CA 94080
| | - Ann Dean
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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23
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Hafer TL, Felton A, Delgado Y, Srinivasan H, Emerman M. A CRISPR Screen of HIV Dependency Factors Reveals That CCNT1 Is Non-Essential in T Cells but Required for HIV-1 Reactivation from Latency. Viruses 2023; 15:1863. [PMID: 37766271 PMCID: PMC10535513 DOI: 10.3390/v15091863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
We sought to explore the hypothesis that host factors required for HIV-1 replication also play a role in latency reversal. Using a CRISPR gene library of putative HIV dependency factors, we performed a screen to identify genes required for latency reactivation. We identified several HIV-1 dependency factors that play a key role in HIV-1 latency reactivation including ELL, UBE2M, TBL1XR1, HDAC3, AMBRA1, and ALYREF. The knockout of Cyclin T1 (CCNT1), a component of the P-TEFb complex that is important for transcription elongation, was the top hit in the screen and had the largest effect on HIV latency reversal with a wide variety of latency reversal agents. Moreover, CCNT1 knockout prevents latency reactivation in a primary CD4+ T cell model of HIV latency without affecting the activation of these cells. RNA sequencing data showed that CCNT1 regulates HIV-1 proviral genes to a larger extent than any other host gene and had no significant effects on RNA transcripts in primary T cells after activation. We conclude that CCNT1 function is non-essential in T cells but is absolutely required for HIV latency reversal.
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Affiliation(s)
- Terry L. Hafer
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA;
| | - Abby Felton
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Yennifer Delgado
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Harini Srinivasan
- Bioinformatics Shared Resource, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Michael Emerman
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
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24
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Hafer TL, Felton A, Delgado Y, Srinivasan H, Emerman M. A CRISPR screen of HIV dependency factors reveals CCNT1 is non-essential in T cells but required for HIV-1 reactivation from latency. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551016. [PMID: 37546973 PMCID: PMC10402164 DOI: 10.1101/2023.07.28.551016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
We sought to explore the hypothesis that host factors required for HIV-1 replication also play a role in latency reversal. Using a CRISPR gene library of putative HIV dependency factors, we performed a screen to identify genes required for latency reactivation. We identified several HIV-1 dependency factors that play a key role in HIV-1 latency reactivation including ELL , UBE2M , TBL1XR1 , HDAC3 , AMBRA1 , and ALYREF . Knockout of Cyclin T1 ( CCNT1 ), a component of the P-TEFb complex important for transcription elongation, was the top hit in the screen and had the largest effect on HIV latency reversal with a wide variety of latency reversal agents. Moreover, CCNT1 knockout prevents latency reactivation in a primary CD4+ T cell model of HIV latency without affecting activation of these cells. RNA sequencing data showed that CCNT1 regulates HIV-1 proviral genes to a larger extent than any other host gene and had no significant effects on RNA transcripts in primary T cells after activation. We conclude that CCNT1 function is redundant in T cells but is absolutely required for HIV latency reversal.
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Affiliation(s)
- Terry L Hafer
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Abby Felton
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Yennifer Delgado
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Harini Srinivasan
- Bioinformatics Shared Resource, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Michael Emerman
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
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25
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Belew MD, Chien E, Michael WM. Characterization of factors that underlie transcriptional silencing in C. elegans oocytes. PLoS Genet 2023; 19:e1010831. [PMID: 37478128 PMCID: PMC10395837 DOI: 10.1371/journal.pgen.1010831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/15/2023] [Indexed: 07/23/2023] Open
Abstract
While it has been appreciated for decades that prophase-arrested oocytes are transcriptionally silenced on a global level, the molecular pathways that promote silencing have remained elusive. Previous work in C. elegans has shown that both topoisomerase II (TOP-2) and condensin II collaborate with the H3K9me heterochromatin pathway to silence gene expression in the germline during L1 starvation, and that the PIE-1 protein silences the genome in the P-lineage of early embryos. Here, we show that all three of these silencing systems, TOP-2/condensin II, H3K9me, and PIE-1, are required for transcriptional repression in oocytes. We find that H3K9me3 marks increase dramatically on chromatin during silencing, and that silencing is under cell cycle control. We also find that PIE-1 localizes to the nucleolus just prior to silencing, and that nucleolar dissolution during silencing is dependent on TOP-2/condensin II. Our data identify both the molecular components and the trigger for genome silencing in oocytes and establish a link between PIE-1 nucleolar residency and its ability to repress transcription.
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Affiliation(s)
- Mezmur D Belew
- Department of Biological Sciences, Molecular and Computational Biology Section, University of Southern California, Los Angeles, California, United States of America
| | - Emilie Chien
- Department of Biological Sciences, Molecular and Computational Biology Section, University of Southern California, Los Angeles, California, United States of America
| | - W Matthew Michael
- Department of Biological Sciences, Molecular and Computational Biology Section, University of Southern California, Los Angeles, California, United States of America
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26
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Palumbo RJ, Hanes SD. Catalytic activity of the Bin3/MEPCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.01.543302. [PMID: 37333392 PMCID: PMC10274667 DOI: 10.1101/2023.06.01.543302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Methylphosphate Capping Enzyme (MEPCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MEPCE in vitro, little is known about its functions in vivo, or what roles- if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MEPCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MEPCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MEPCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
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27
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Camara MB, Sobeh AM, Eichhorn CD. Progress in 7SK ribonucleoprotein structural biology. Front Mol Biosci 2023; 10:1154622. [PMID: 37051324 PMCID: PMC10083321 DOI: 10.3389/fmolb.2023.1154622] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/16/2023] [Indexed: 03/29/2023] Open
Abstract
The 7SK ribonucleoprotein (RNP) is a dynamic and multifunctional regulator of RNA Polymerase II (RNAPII) transcription in metazoa. Comprised of the non-coding 7SK RNA, core proteins, and numerous accessory proteins, the most well-known 7SK RNP function is the sequestration and inactivation of the positive transcription elongation factor b (P-TEFb). More recently, 7SK RNP has been shown to regulate RNAPII transcription through P-TEFb-independent pathways. Due to its fundamental role in cellular function, dysregulation has been linked with human diseases including cancers, heart disease, developmental disorders, and viral infection. Significant advances in 7SK RNP structural biology have improved our understanding of 7SK RNP assembly and function. Here, we review progress in understanding the structural basis of 7SK RNA folding, biogenesis, and RNP assembly.
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Affiliation(s)
- Momodou B. Camara
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
| | - Amr M. Sobeh
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
| | - Catherine D. Eichhorn
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
- Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE, United States
- *Correspondence: Catherine D. Eichhorn,
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