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Mooney RA, Zhu J, Saba J, Landick R. NusG-Spt5 Transcription Factors: Universal, Dynamic Modulators of Gene Expression. J Mol Biol 2024:168814. [PMID: 39374889 DOI: 10.1016/j.jmb.2024.168814] [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: 07/01/2024] [Revised: 09/22/2024] [Accepted: 10/02/2024] [Indexed: 10/09/2024]
Abstract
The accurate and efficient biogenesis of RNA by cellular RNA polymerase (RNAP) requires accessory factors that regulate the initiation, elongation, and termination of transcription. Of the many discovered to date, the elongation regulator NusG-Spt5 is the only universally conserved transcription factor. With orthologs and paralogs found in all three domains of life, this ubiquity underscores their ancient and essential regulatory functions. NusG-Spt5 proteins evolved to maintain a similar binding interface to RNAP through contacts of the NusG N-terminal domain (NGN) that bridge the main DNA-binding cleft. We propose that varying strength of these contacts, modulated by tethering interactions, either decrease transcriptional pausing by smoothing the rugged thermodynamic landscape of transcript elongation or enhance pausing, depending on which conformation of RNAP is stabilized by NGN contacts. NusG-Spt5 contains one (in bacteria and archaea) or more (in eukaryotes) C-terminal domains that use a KOW fold to contact diverse targets, tether the NGN, and control RNA biogenesis. Recent work highlights these diverse functions in different organisms. Some bacteria contain multiple specialized NusG paralogs that regulate subsets of operons via sequence-specific targeting, controlling production of antibiotics, toxins, or capsule proteins. Despite their common origin, NusG orthologs can differ in their target selection, interacting partners, and effects on RNA synthesis. We describe the current understanding of NusG-Spt5 structure, interactions with RNAP and other regulators, and cellular functions including significant recent progress from genome-wide analyses, single-molecule visualization, and cryo-EM. The recent findings highlight the remarkable diversity of function among these structurally conserved proteins.
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Affiliation(s)
- Rachel A Mooney
- Department of Biochemistry, University of Wisconsin- Madison, 1550 Linden Drive, Madison, WI 53706.
| | - Junqiao Zhu
- Department of Biochemistry, University of Wisconsin- Madison, 1550 Linden Drive, Madison, WI 53706
| | - Jason Saba
- Department of Biochemistry, University of Wisconsin- Madison, 1550 Linden Drive, Madison, WI 53706
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin- Madison, 1550 Linden Drive, Madison, WI 53706; Department of Bacteriology, University of Wisconsin- Madison, 1550 Linden Drive, Madison, WI 53706.
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2
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Ferdoush J, Kadir RA, Ogle M, Saha A. Regulation of eukaryotic transcription initiation in response to cellular stress. Gene 2024; 924:148616. [PMID: 38795856 DOI: 10.1016/j.gene.2024.148616] [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: 11/22/2023] [Revised: 05/17/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
Transcription initiation is a vital step in the regulation of eukaryotic gene expression. It can be dysregulated in response to various cellular stressors which is associated with numerous human diseases including cancer. Transcription initiation is facilitated via many gene-specific trans-regulatory elements such as transcription factors, activators, and coactivators through their interactions with transcription pre-initiation complex (PIC). These trans-regulatory elements can uniquely facilitate PIC formation (hence, transcription initiation) in response to cellular nutrient stress. Cellular nutrient stress also regulates the activity of other pathways such as target of rapamycin (TOR) pathway. TOR pathway exhibits distinct regulatory mechanisms of transcriptional activation in response to stress. Like TOR pathway, the cell cycle regulatory pathway is also found to be linked to transcriptional regulation in response to cellular stress. Several transcription factors such as p53, C/EBP Homologous Protein (CHOP), activating transcription factor 6 (ATF6α), E2F, transforming growth factor (TGF)-β, Adenomatous polyposis coli (APC), SMAD, and MYC have been implicated in regulation of transcription of target genes involved in cell cycle progression, apoptosis, and DNA damage repair pathways. Additionally, cellular metabolic and oxidative stressors have been found to regulate the activity of long non-coding RNAs (lncRNA). LncRNA regulates transcription by upregulating or downregulating the transcription regulatory proteins involved in metabolic and cell signaling pathways. Numerous human diseases, triggered by chronic cellular stressors, are associated with abnormal regulation of transcription. Hence, understanding these mechanisms would help unravel the molecular regulatory insights with potential therapeutic interventions. Therefore, here we emphasize the recent advances of regulation of eukaryotic transcription initiation in response to cellular stress.
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Affiliation(s)
- Jannatul Ferdoush
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga, 615 McCallie Ave, Chattanooga, TN 37403, USA.
| | - Rizwaan Abdul Kadir
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga, 615 McCallie Ave, Chattanooga, TN 37403, USA
| | - Matthew Ogle
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga, 615 McCallie Ave, Chattanooga, TN 37403, USA
| | - Ayan Saha
- Department of Bioinformatics and Biotechnology, Asian University for Women, Chattogram, Bangladesh
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3
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Diao AJ, Su BG, Vos SM. Pause Patrol: Negative Elongation Factor's Role in Promoter-Proximal Pausing and Beyond. J Mol Biol 2024:168779. [PMID: 39241983 DOI: 10.1016/j.jmb.2024.168779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/27/2024] [Accepted: 08/30/2024] [Indexed: 09/09/2024]
Abstract
RNA polymerase (Pol) II is highly regulated to ensure appropriate gene expression. Early transcription elongation is associated with transient pausing of RNA Pol II in the promoter-proximal region. In multicellular organisms, this pausing is stabilized by the association of transcription elongation factors DRB-sensitivity inducing factor (DSIF) and Negative Elongation Factor (NELF). DSIF is a broadly conserved transcription elongation factor whereas NELF is mostly restricted to the metazoan lineage. Mounting evidence suggests that NELF association with RNA Pol II serves as checkpoint for either release into rapid and productive transcription elongation or premature termination at promoter-proximal pause sites. Here we summarize NELF's roles in promoter-proximal pausing, transcription termination, DNA repair, and signaling based on decades of cell biological, biochemical, and structural work and describe areas for future research.
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Affiliation(s)
- Annette J Diao
- Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, United States
| | - Bonnie G Su
- Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, United States
| | - Seychelle M Vos
- Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, United States; Howard Hughes Medical Institute, United States.
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4
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Capatina AL, Malcolm JR, Stenning J, Moore RL, Bridge KS, Brackenbury WJ, Holding AN. Hypoxia-induced epigenetic regulation of breast cancer progression and the tumour microenvironment. Front Cell Dev Biol 2024; 12:1421629. [PMID: 39282472 PMCID: PMC11392762 DOI: 10.3389/fcell.2024.1421629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 08/19/2024] [Indexed: 09/19/2024] Open
Abstract
The events that control breast cancer progression and metastasis are complex and intertwined. Hypoxia plays a key role both in oncogenic transformation and in fueling the metastatic potential of breast cancer cells. Here we review the impact of hypoxia on epigenetic regulation of breast cancer, by interfering with multiple aspects of the tumour microenvironment. The co-dependent relationship between oxygen depletion and metabolic shift to aerobic glycolysis impacts on a range of enzymes and metabolites available in the cell, promoting posttranslational modifications of histones and chromatin, and changing the gene expression landscape to facilitate tumour development. Hormone signalling, particularly through ERα, is also tightly regulated by hypoxic exposure, with HIF-1α expression being a prognostic marker for therapeutic resistance in ER+ breast cancers. This highlights the strong need to understand the hypoxia-endocrine signalling axis and exploit it as a therapeutic target. Furthermore, hypoxia has been shown to enhance metastasis in TNBC cells, as well as promoting resistance to taxanes, radiotherapy and even immunotherapy through microRNA regulation and changes in histone packaging. Finally, several other mediators of the hypoxic response are discussed. We highlight a link between ionic dysregulation and hypoxia signalling, indicating a potential connection between HIF-1α and tumoural Na+ accumulation which would be worth further exploration; we present the role of Ca2+ in mediating hypoxic adaptation via chromatin remodelling, transcription factor recruitment and changes in signalling pathways; and we briefly summarise some of the findings regarding vesicle secretion and paracrine induced epigenetic reprogramming upon hypoxic exposure in breast cancer. By summarising these observations, this article highlights the heterogeneity of breast cancers, presenting a series of pathways with potential for therapeutic applications.
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Affiliation(s)
| | - Jodie R Malcolm
- Department of Biology, University of York, York, United Kingdom
| | - Jack Stenning
- Department of Biology, University of York, York, United Kingdom
| | - Rachael L Moore
- York Biomedical Research Institute, University of York, York, United Kingdom
| | - Katherine S Bridge
- Department of Biology, University of York, York, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom
| | - William J Brackenbury
- Department of Biology, University of York, York, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom
| | - Andrew N Holding
- Department of Biology, University of York, York, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom
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5
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Mante J, Groover KE, Pullen RM. Environmental community transcriptomics: strategies and struggles. Brief Funct Genomics 2024:elae033. [PMID: 39183066 DOI: 10.1093/bfgp/elae033] [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: 05/10/2024] [Revised: 08/02/2024] [Accepted: 08/08/2024] [Indexed: 08/27/2024] Open
Abstract
Transcriptomics is the study of RNA transcripts, the portion of the genome that is transcribed, in a specific cell, tissue, or organism. Transcriptomics provides insight into gene expression patterns, regulation, and the underlying mechanisms of cellular processes. Community transcriptomics takes this a step further by studying the RNA transcripts from environmental assemblies of organisms, with the intention of better understanding the interactions between members of the community. Community transcriptomics requires successful extraction of RNA from a diverse set of organisms and subsequent analysis via mapping those reads to a reference genome or de novo assembly of the reads. Both, extraction protocols and the analysis steps can pose hurdles for community transcriptomics. This review covers advances in transcriptomic techniques and assesses the viability of applying them to community transcriptomics.
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Affiliation(s)
- Jeanet Mante
- Oak Ridge Associated Universities, Oak Ridge, 37831, TN, USA
| | - Kyra E Groover
- Department of Molecular Biosciences, University of Texas at Austin, Austin, 78705, TX, USA
| | - Randi M Pullen
- DEVCOM Army Research Laboratory, Adelphi, 20783, MD, USA
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6
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Sun R, Fisher RP. The CDK9-SPT5 Axis in Control of Transcription Elongation by RNAPII. J Mol Biol 2024:168746. [PMID: 39147127 DOI: 10.1016/j.jmb.2024.168746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 08/09/2024] [Accepted: 08/09/2024] [Indexed: 08/17/2024]
Abstract
The RNA polymerase II (RNAPII) transcription cycle is regulated at every stage by a network of cyclin-dependent protein kinases (CDKs) and protein phosphatases. Progression of RNAPII from initiation to termination is marked by changing patterns of phosphorylation on the highly repetitive carboxy-terminal domain (CTD) of RPB1, its largest subunit, suggesting the existence of a CTD code. In parallel, the conserved transcription elongation factor SPT5, large subunit of the DRB sensitivity-inducing factor (DSIF), undergoes spatiotemporally regulated changes in phosphorylation state that may be directly linked to the transitions between transcription-cycle phases. Here we review insights gained from recent structural, biochemical, and genetic analyses of human SPT5, which suggest that two of its phosphorylated regions perform distinct functions at different points in transcription. Phosphorylation within a flexible, RNA-binding linker promotes release from the promoter-proximal pause-frequently a rate-limiting step in gene expression-whereas modifications in a repetitive carboxy-terminal region are thought to favor processive elongation, and are removed just prior to termination. Phosphorylations in both motifs depend on CDK9, catalytic subunit of positive transcription elongation factor b (P-TEFb); their different timing of accumulation on chromatin and function during the transcription cycle might reflect their removal by different phosphatases, different kinetics of phosphorylation by CDK9, or both. Perturbations of SPT5 regulation have profound impacts on viability and development in model organisms through largely unknown mechanisms, while enzymes that modify SPT5 have emerged as potential therapeutic targets in cancer; elucidating a putative SPT5 code is therefore a high priority.
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Affiliation(s)
- Rui Sun
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574, USA
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574, USA.
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7
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Versluis P, Graham TGW, Eng V, Ebenezer J, Darzacq X, Zipfel WR, Lis JT. Live-cell imaging of RNA Pol II and elongation factors distinguishes competing mechanisms of transcription regulation. Mol Cell 2024; 84:2856-2869.e9. [PMID: 39121843 DOI: 10.1016/j.molcel.2024.07.009] [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: 12/20/2023] [Revised: 04/22/2024] [Accepted: 07/11/2024] [Indexed: 08/12/2024]
Abstract
RNA polymerase II (RNA Pol II)-mediated transcription is a critical, highly regulated process aided by protein complexes at distinct steps. Here, to investigate RNA Pol II and transcription-factor-binding and dissociation dynamics, we generated endogenous photoactivatable-GFP (PA-GFP) and HaloTag knockins using CRISPR-Cas9, allowing us to track a population of molecules at the induced Hsp70 loci in Drosophila melanogaster polytene chromosomes. We found that early in the heat-shock response, little RNA Pol II and DRB sensitivity-inducing factor (DSIF) are reused for iterative rounds of transcription. Surprisingly, although PAF1 and Spt6 are found throughout the gene body by chromatin immunoprecipitation (ChIP) assays, they show markedly different binding behaviors. Additionally, we found that PAF1 and Spt6 are only recruited after positive transcription elongation factor (P-TEFb)-mediated phosphorylation and RNA Pol II promoter-proximal pause escape. Finally, we observed that PAF1 may be expendable for transcription of highly expressed genes where nucleosome density is low. Thus, our live-cell imaging data provide key constraints to mechanistic models of transcription regulation.
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Affiliation(s)
- Philip Versluis
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Thomas G W Graham
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Vincent Eng
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jonathan Ebenezer
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA; Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Xavier Darzacq
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Warren R Zipfel
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - John T Lis
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
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8
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Walker RL, Hornicek FJ, Duan Z. Transcriptional regulation and therapeutic potential of cyclin-dependent kinase 9 (CDK9) in sarcoma. Biochem Pharmacol 2024; 226:116342. [PMID: 38848777 DOI: 10.1016/j.bcp.2024.116342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/17/2024] [Accepted: 06/04/2024] [Indexed: 06/09/2024]
Abstract
Sarcomas include various subtypes comprising two significant groups - soft tissue and bone sarcomas. Although the survival rate for some sarcoma subtypes has improved over time, the current methods of treatment remain efficaciously limited, as recurrent, and metastatic diseases remain a major obstacle. There is a need for better options and therapeutic strategies in treating sarcoma. Cyclin dependent kinase 9 (CDK9) is a transcriptional kinase and has emerged as a promising target for treating various cancers. The aberrant expression and activation of CDK9 have been observed in several sarcoma subtypes, including rhabdomyosarcoma, synovial sarcoma, osteosarcoma, Ewing sarcoma, and chordoma. Enhanced CDK9 expression has also been correlated with poorer prognosis in sarcoma patients. As a master regulator of transcription, CDK9 promotes transcription elongation by phosphorylation and releasing RNA polymerase II (RNAPII) from its promoter proximal pause. Release of RNAPII from this pause induces transcription of critical genes in the tumor cell. Overexpression and activation of CDK9 have been observed to lead to the expression of oncogenes, including MYC and MCL-1, that aid sarcoma development and progression. Inhibition of CDK9 in sarcoma has been proven to reduce these oncogenes' expression and decrease proliferation and growth in different sarcoma cells. Currently, there are several CDK9 inhibitors in preclinical and clinical investigations. This review aims to highlight the recent discovery and results on the transcriptional role and therapeutic potential of CDK9 in sarcoma.
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Affiliation(s)
- Robert L Walker
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA
| | - Francis J Hornicek
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA
| | - Zhenfeng Duan
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA.
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9
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Sabath K, Nabih A, Arnold C, Moussa R, Domjan D, Zaugg JB, Jonas S. Basis of gene-specific transcription regulation by the Integrator complex. Mol Cell 2024; 84:2525-2541.e12. [PMID: 38906142 DOI: 10.1016/j.molcel.2024.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 03/04/2024] [Accepted: 05/29/2024] [Indexed: 06/23/2024]
Abstract
The Integrator complex attenuates gene expression via the premature termination of RNA polymerase II (RNAP2) at promoter-proximal pausing sites. It is required for stimulus response, cell differentiation, and neurodevelopment, but how gene-specific and adaptive regulation by Integrator is achieved remains unclear. Here, we identify two sites on human Integrator subunits 13/14 that serve as binding hubs for sequence-specific transcription factors (TFs) and other transcription effector complexes. When Integrator is attached to paused RNAP2, these hubs are positioned upstream of the transcription bubble, consistent with simultaneous TF-promoter tethering. The TFs co-localize with Integrator genome-wide, increase Integrator abundance on target genes, and co-regulate responsive transcriptional programs. For instance, sensory cilia formation induced by glucose starvation depends on Integrator-TF contacts. Our data suggest TF-mediated promoter recruitment of Integrator as a widespread mechanism for targeted transcription regulation.
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Affiliation(s)
- Kevin Sabath
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.
| | - Amena Nabih
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Christian Arnold
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Rim Moussa
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - David Domjan
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Judith B Zaugg
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Stefanie Jonas
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.
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10
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D'Orso I. The HIV-1 Transcriptional Program: From Initiation to Elongation Control. J Mol Biol 2024:168690. [PMID: 38936695 DOI: 10.1016/j.jmb.2024.168690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/29/2024]
Abstract
A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
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Affiliation(s)
- Iván D'Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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11
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Hsiao YT, Liao IH, Wu BK, Chu HPC, Hsieh CL. Probing chromatin condensation dynamics in live cells using interferometric scattering correlation spectroscopy. Commun Biol 2024; 7:763. [PMID: 38914653 PMCID: PMC11196589 DOI: 10.1038/s42003-024-06457-2] [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: 11/24/2023] [Accepted: 06/14/2024] [Indexed: 06/26/2024] Open
Abstract
Chromatin organization and dynamics play important roles in governing the regulation of nuclear processes of biological cells. However, due to the constant diffusive motion of chromatin, examining chromatin nanostructures in living cells has been challenging. In this study, we introduce interferometric scattering correlation spectroscopy (iSCORS) to spatially map nanoscopic chromatin configurations within unlabeled live cell nuclei. This label-free technique captures time-varying linear scattering signals generated by the motion of native chromatin on a millisecond timescale, allowing us to deduce chromatin condensation states. Using iSCORS imaging, we quantitatively examine chromatin dynamics over extended periods, revealing spontaneous fluctuations in chromatin condensation and heterogeneous compaction levels in interphase cells, independent of cell phases. Moreover, we observe changes in iSCORS signals of chromatin upon transcription inhibition, indicating that iSCORS can probe nanoscopic chromatin structures and dynamics associated with transcriptional activities. Our scattering-based optical microscopy, which does not require labeling, serves as a powerful tool for visualizing dynamic chromatin nano-arrangements in live cells. This advancement holds promise for studying chromatin remodeling in various crucial cellular processes, such as stem cell differentiation, mechanotransduction, and DNA repair.
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Affiliation(s)
- Yi-Teng Hsiao
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, Taipei, Taiwan
| | - I-Hsin Liao
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, Taipei, Taiwan
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Bo-Kuan Wu
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, Taipei, Taiwan
| | | | - Chia-Lung Hsieh
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, Taipei, Taiwan.
- Department of Physics, National Taiwan University, Taipei, Taiwan.
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12
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Velychko T, Mohammad E, Ferrer-Vicens I, Parfentev I, Werner M, Studniarek C, Schwalb B, Urlaub H, Murphy S, Cramer P, Lidschreiber M. CDK7 kinase activity promotes RNA polymerase II promoter escape by facilitating initiation factor release. Mol Cell 2024; 84:2287-2303.e10. [PMID: 38821049 DOI: 10.1016/j.molcel.2024.05.007] [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: 12/02/2022] [Revised: 02/01/2024] [Accepted: 05/08/2024] [Indexed: 06/02/2024]
Abstract
Cyclin-dependent kinase 7 (CDK7), part of the general transcription factor TFIIH, promotes gene transcription by phosphorylating the C-terminal domain of RNA polymerase II (RNA Pol II). Here, we combine rapid CDK7 kinase inhibition with multi-omics analysis to unravel the direct functions of CDK7 in human cells. CDK7 inhibition causes RNA Pol II retention at promoters, leading to decreased RNA Pol II initiation and immediate global downregulation of transcript synthesis. Elongation, termination, and recruitment of co-transcriptional factors are not directly affected. Although RNA Pol II, initiation factors, and Mediator accumulate at promoters, RNA Pol II complexes can also proceed into gene bodies without promoter-proximal pausing while retaining initiation factors and Mediator. Further downstream, RNA Pol II phosphorylation increases and initiation factors and Mediator are released, allowing recruitment of elongation factors and an increase in RNA Pol II elongation velocity. Collectively, CDK7 kinase activity promotes the release of initiation factors and Mediator from RNA Pol II, facilitating RNA Pol II escape from the promoter.
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Affiliation(s)
- Taras Velychko
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Eusra Mohammad
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ivan Ferrer-Vicens
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Iwan Parfentev
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Marcel Werner
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Cecilia Studniarek
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Björn Schwalb
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany; Institute of Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Michael Lidschreiber
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.
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13
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Žumer K, Ochmann M, Aljahani A, Zheenbekova A, Devadas A, Maier KC, Rus P, Neef U, Oudelaar AM, Cramer P. FACT maintains chromatin architecture and thereby stimulates RNA polymerase II pausing during transcription in vivo. Mol Cell 2024; 84:2053-2069.e9. [PMID: 38810649 DOI: 10.1016/j.molcel.2024.05.003] [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: 10/30/2023] [Revised: 03/06/2024] [Accepted: 05/02/2024] [Indexed: 05/31/2024]
Abstract
Facilitates chromatin transcription (FACT) is a histone chaperone that supports transcription through chromatin in vitro, but its functional roles in vivo remain unclear. Here, we analyze the in vivo functions of FACT with the use of multi-omics analysis after rapid FACT depletion from human cells. We show that FACT depletion destabilizes chromatin and leads to transcriptional defects, including defective promoter-proximal pausing and elongation, and increased premature termination of RNA polymerase II. Unexpectedly, our analysis revealed that promoter-proximal pausing depends not only on the negative elongation factor (NELF) but also on the +1 nucleosome, which is maintained by FACT.
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Affiliation(s)
- Kristina Žumer
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Moritz Ochmann
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Abrar Aljahani
- Max Planck Institute for Multidisciplinary Sciences, Genome Organization and Regulation, Am Fassberg 11, 37077 Göttingen, Germany
| | - Aiturgan Zheenbekova
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Arjun Devadas
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Kerstin Caroline Maier
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Petra Rus
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ute Neef
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - A Marieke Oudelaar
- Max Planck Institute for Multidisciplinary Sciences, Genome Organization and Regulation, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Patrick Cramer
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
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14
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Li Y, Wang Q, Xu Y, Li Z. Structures of co-transcriptional RNA capping enzymes on paused transcription complex. Nat Commun 2024; 15:4622. [PMID: 38816438 PMCID: PMC11139899 DOI: 10.1038/s41467-024-48963-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
The 5'-end capping of nascent pre-mRNA represents the initial step in RNA processing, with evidence demonstrating that guanosine addition and 2'-O-ribose methylation occur in tandem with early steps of transcription by RNA polymerase II, especially at the pausing stage. Here, we determine the cryo-EM structures of the paused elongation complex in complex with RNGTT, as well as the paused elongation complex in complex with RNGTT and CMTR1. Our findings show the simultaneous presence of RNGTT and the NELF complex bound to RNA polymerase II. The NELF complex exhibits two conformations, one of which shows a notable rearrangement of NELF-A/D compared to that of the paused elongation complex. Moreover, CMTR1 aligns adjacent to RNGTT on the RNA polymerase II stalk. Our structures indicate that RNGTT and CMTR1 directly bind the paused elongation complex, illuminating the mechanism by which 5'-end capping of pre-mRNA during transcriptional pausing.
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Affiliation(s)
- Yan Li
- 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, 200032, China
| | - Qianmin Wang
- 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, 200032, China
| | - Yanhui Xu
- 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, 200032, China
- The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Ze Li
- 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, 200032, China.
- The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China.
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15
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Rosenthal ZC, Fass DM, Payne NC, She A, Patnaik D, Hennig KM, Tesla R, Werthmann GC, Guhl C, Reis SA, Wang X, Chen Y, Placzek M, Williams NS, Hooker J, Herz J, Mazitschek R, Haggarty SJ. Epigenetic modulation through BET bromodomain inhibitors as a novel therapeutic strategy for progranulin-deficient frontotemporal dementia. Sci Rep 2024; 14:9064. [PMID: 38643236 PMCID: PMC11032351 DOI: 10.1038/s41598-024-59110-7] [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: 12/06/2023] [Accepted: 04/08/2024] [Indexed: 04/22/2024] Open
Abstract
Frontotemporal dementia (FTD) is a debilitating neurodegenerative disorder with currently no disease-modifying treatment options available. Mutations in GRN are one of the most common genetic causes of FTD, near ubiquitously resulting in progranulin (PGRN) haploinsufficiency. Small molecules that can restore PGRN protein to healthy levels in individuals bearing a heterozygous GRN mutation may thus have therapeutic value. Here, we show that epigenetic modulation through bromodomain and extra-terminal domain (BET) inhibitors (BETi) potently enhance PGRN protein levels, both intracellularly and secreted forms, in human central nervous system (CNS)-relevant cell types, including in microglia-like cells. In terms of potential for disease modification, we show BETi treatment effectively restores PGRN levels in neural cells with a GRN mutation known to cause PGRN haploinsufficiency and FTD. We demonstrate that BETi can rapidly and durably enhance PGRN in neural progenitor cells (NPCs) in a manner dependent upon BET protein expression, suggesting a gain-of-function mechanism. We further describe a CNS-optimized BETi chemotype that potently engages endogenous BRD4 and enhances PGRN expression in neuronal cells. Our results reveal a new epigenetic target for treating PGRN-deficient forms of FTD and provide mechanistic insight to aid in translating this discovery into therapeutics.
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Affiliation(s)
- Zachary C Rosenthal
- Chemical Neurobiology Laboratory, Precision Therapeutics Unit, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Daniel M Fass
- Chemical Neurobiology Laboratory, Precision Therapeutics Unit, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - N Connor Payne
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, USA
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, USA
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Angela She
- Chemical Neurobiology Laboratory, Precision Therapeutics Unit, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - Debasis Patnaik
- Chemical Neurobiology Laboratory, Precision Therapeutics Unit, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - Krista M Hennig
- Chemical Neurobiology Laboratory, Precision Therapeutics Unit, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - Rachel Tesla
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gordon C Werthmann
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Charlotte Guhl
- Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Surya A Reis
- Chemical Neurobiology Laboratory, Precision Therapeutics Unit, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - Xiaoyu Wang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yueting Chen
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, USA
| | - Michael Placzek
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, USA
| | - Noelle S Williams
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jacob Hooker
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, USA
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ralph Mazitschek
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, USA
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Stephen J Haggarty
- Chemical Neurobiology Laboratory, Precision Therapeutics Unit, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA.
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16
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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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17
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Mbonye U, Karn J. The cell biology of HIV-1 latency and rebound. Retrovirology 2024; 21:6. [PMID: 38580979 PMCID: PMC10996279 DOI: 10.1186/s12977-024-00639-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024] Open
Abstract
Transcriptionally latent forms of replication-competent proviruses, present primarily in a small subset of memory CD4+ T cells, pose the primary barrier to a cure for HIV-1 infection because they are the source of the viral rebound that almost inevitably follows the interruption of antiretroviral therapy. Over the last 30 years, many of the factors essential for initiating HIV-1 transcription have been identified in studies performed using transformed cell lines, such as the Jurkat T-cell model. However, as highlighted in this review, several poorly understood mechanisms still need to be elucidated, including the molecular basis for promoter-proximal pausing of the transcribing complex and the detailed mechanism of the delivery of P-TEFb from 7SK snRNP. Furthermore, the central paradox of HIV-1 transcription remains unsolved: how are the initial rounds of transcription achieved in the absence of Tat? A critical limitation of the transformed cell models is that they do not recapitulate the transitions between active effector cells and quiescent memory T cells. Therefore, investigation of the molecular mechanisms of HIV-1 latency reversal and LRA efficacy in a proper physiological context requires the utilization of primary cell models. Recent mechanistic studies of HIV-1 transcription using latently infected cells recovered from donors and ex vivo cellular models of viral latency have demonstrated that the primary blocks to HIV-1 transcription in memory CD4+ T cells are restrictive epigenetic features at the proviral promoter, the cytoplasmic sequestration of key transcription initiation factors such as NFAT and NF-κB, and the vanishingly low expression of the cellular transcription elongation factor P-TEFb. One of the foremost schemes to eliminate the residual reservoir is to deliberately reactivate latent HIV-1 proviruses to enable clearance of persisting latently infected cells-the "Shock and Kill" strategy. For "Shock and Kill" to become efficient, effective, non-toxic latency-reversing agents (LRAs) must be discovered. Since multiple restrictions limit viral reactivation in primary cells, understanding the T-cell signaling mechanisms that are essential for stimulating P-TEFb biogenesis, initiation factor activation, and reversing the proviral epigenetic restrictions have become a prerequisite for the development of more effective LRAs.
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Affiliation(s)
- Uri Mbonye
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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18
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Su BG, Vos SM. Distinct negative elongation factor conformations regulate RNA polymerase II promoter-proximal pausing. Mol Cell 2024; 84:1243-1256.e5. [PMID: 38401543 PMCID: PMC10997474 DOI: 10.1016/j.molcel.2024.01.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/17/2023] [Accepted: 01/25/2024] [Indexed: 02/26/2024]
Abstract
Metazoan gene expression regulation involves pausing of RNA polymerase (Pol II) in the promoter-proximal region of genes and is stabilized by DSIF and NELF. Upon depletion of elongation factors, NELF appears to accompany elongating Pol II past pause sites; however, prior work indicates that NELF prevents Pol II elongation. Here, we report cryoelectron microscopy structures of Pol II-DSIF-NELF complexes with NELF in two distinct conformations corresponding to paused and poised states. The paused NELF state supports Pol II stalling, whereas the poised NELF state enables transcription elongation as it does not support a tilted RNA-DNA hybrid. Further, the poised NELF state can accommodate TFIIS binding to Pol II, allowing for Pol II reactivation at paused or backtracking sites. Finally, we observe that the NELF-A tentacle interacts with the RPB2 protrusion and is necessary for pausing. Our results define how NELF can support pausing, reactivation, and elongation by Pol II.
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Affiliation(s)
- Bonnie G Su
- Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, USA
| | - Seychelle M Vos
- Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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19
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Hardtke HA, Zhang YJ. Collaborators or competitors: the communication between RNA polymerase II and the nucleosome during eukaryotic transcription. Crit Rev Biochem Mol Biol 2024; 59:1-19. [PMID: 38288999 PMCID: PMC11209794 DOI: 10.1080/10409238.2024.2306365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 01/12/2024] [Indexed: 04/22/2024]
Abstract
Decades of scientific research have been devoted to unraveling the intricacies of eukaryotic transcription since the groundbreaking discovery of eukaryotic RNA polymerases in the late 1960s. RNA polymerase II, the polymerase responsible for mRNA synthesis, has always attracted the most attention. Despite its structural resemblance to its bacterial counterpart, eukaryotic RNA polymerase II faces a unique challenge in progressing transcription due to the presence of nucleosomes that package DNA in the nuclei. In this review, we delve into the impact of RNA polymerase II and histone signaling on the progression of eukaryotic transcription. We explore the pivotal points of interactions that bridge the RNA polymerase II and histone signaling systems. Finally, we present an analysis of recent cryo-electron microscopy structures, which captured RNA polymerase II-nucleosome complexes at different stages of the transcription cycle. The combination of the signaling crosstalk and the direct visualization of RNA polymerase II-nucleosome complexes provides a deeper understanding of the communication between these two major players in eukaryotic transcription.
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Affiliation(s)
- Haley A. Hardtke
- Department of Molecular Biosciences, University of Texas, Austin
| | - Y. Jessie Zhang
- Department of Molecular Biosciences, University of Texas, Austin
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20
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Aoki K, Nitta A, Igarashi A. NELF and PAF1C complexes are core transcriptional machineries controlling colon cancer stemness. Oncogene 2024; 43:566-577. [PMID: 38182897 PMCID: PMC10873196 DOI: 10.1038/s41388-023-02930-0] [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: 07/15/2023] [Revised: 12/01/2023] [Accepted: 12/20/2023] [Indexed: 01/07/2024]
Abstract
Mutations in APC, found in 80% of colon caner, enhance β-catenin stabilization, which is the initial step of colonic tumorigenesis. However, the core transcriptional mechanism underlying the induction of colon cancer stemness by stable β-catenin remains unclear. Here, we found that inducible inhibition of β-catenin suppressed elongation of Pol II and RNA polymerase-associated factor 1 complex (PAF1C) around the transcription start site (TSS) of LGR5. Moreover, stable β-catenin enhanced the formation of active Pol II complex cooperatively with CDC73 and CDK9 by facilitating the recruitment of DRB sensitivity-inducing factor (DSIF) and negative elongation factor (NELF) complexes to the Pol II complex. Subsequently, stable β-catenin facilitated the formation of the Pol II-DSIF-PAF1C complex, suggesting that stable β-catenin induces cancer stemness by stimulating active Pol II complex through NELF and PAF1C. Furthermore, NELF or PAF1C inhibition recapitulated the changes in cancer stemness-related gene expression induced by the inhibition of stable β-catenin and suppressed colon cancer stemness. Additionally, the chemical inhibition of CDK12 (a downstream transcription CDK of PAF1C) suppressed colon cancer stemness. These results suggest that NELF and PAF1C are the core transcriptional machineries that control expression of colon cancer stemness-inducing genes and may be therapeutic targets for colon cancer.
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Affiliation(s)
- Koji Aoki
- Department of Pharmacology, Faculty of Medicine, University of Fukui, Fukui, Japan.
| | - Akari Nitta
- Department of Pharmacology, Faculty of Medicine, University of Fukui, Fukui, Japan
| | - Ayumi Igarashi
- Department of Pharmacology, Faculty of Medicine, University of Fukui, Fukui, Japan
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21
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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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22
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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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23
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Duggan NN, Dragic T, Chanda SK, Pache L. Breaking the Silence: Regulation of HIV Transcription and Latency on the Road to a Cure. Viruses 2023; 15:2435. [PMID: 38140676 PMCID: PMC10747579 DOI: 10.3390/v15122435] [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: 11/21/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Antiretroviral therapy (ART) has brought the HIV/AIDS epidemic under control, but a curative strategy for viral eradication is still needed. The cessation of ART results in rapid viral rebound from latently infected CD4+ T cells, showing that control of viral replication alone does not fully restore immune function, nor does it eradicate viral reservoirs. With a better understanding of factors and mechanisms that promote viral latency, current approaches are primarily focused on the permanent silencing of latently infected cells ("block and lock") or reactivating HIV-1 gene expression in latently infected cells, in combination with immune restoration strategies to eliminate HIV infected cells from the host ("shock and kill"). In this review, we provide a summary of the current, most promising approaches for HIV-1 cure strategies, including an analysis of both latency-promoting agents (LPA) and latency-reversing agents (LRA) that have shown promise in vitro, ex vivo, and in human clinical trials to reduce the HIV-1 reservoir.
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Affiliation(s)
- Natasha N. Duggan
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Tatjana Dragic
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Sumit K. Chanda
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Lars Pache
- NCI Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
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24
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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: 9] [Impact Index Per Article: 9.0] [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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25
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Li T, Tang HC, Tsai KL. Unveiling the noncanonical activation mechanism of CDKs: insights from recent structural studies. Front Mol Biosci 2023; 10:1290631. [PMID: 38028546 PMCID: PMC10666765 DOI: 10.3389/fmolb.2023.1290631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
The Cyclin-dependent kinases (CDKs) play crucial roles in a range of essential cellular processes. While the classical two-step activation mechanism is generally applicable to cell cycle-related CDKs, both CDK7 and CDK8, involved in transcriptional regulation, adopt distinct mechanisms for kinase activation. In both cases, binding to their respective cyclin partners results in only partial activity, while their full activation requires the presence of an additional subunit. Recent structural studies of these two noncanonical kinases have provided unprecedented insights into their activation mechanisms, enabling us to understand how the third subunit coordinates the T-loop stabilization and enhances kinase activity. In this review, we summarize the structure and function of CDK7 and CDK8 within their respective functional complexes, while also describing their noncanonical activation mechanisms. These insights open new avenues for targeted drug discovery and potential therapeutic interventions in various diseases related to CDK7 and CDK8.
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Affiliation(s)
- Tao Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Hui-Chi Tang
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Kuang-Lei Tsai
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
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26
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Pan H, Cheng X, Rodríguez PFG, Zhang X, Chung I, Jin VX, Li W, Hu Y, Li R. An essential signaling function of cytoplasmic NELFB is independent of RNA polymerase II pausing. J Biol Chem 2023; 299:105259. [PMID: 37717699 PMCID: PMC10591015 DOI: 10.1016/j.jbc.2023.105259] [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: 08/10/2023] [Revised: 08/24/2023] [Accepted: 08/30/2023] [Indexed: 09/19/2023] Open
Abstract
The four-subunit negative elongation factor (NELF) complex mediates RNA polymerase II (Pol II) pausing at promoter-proximal regions. Ablation of individual NELF subunits destabilizes the NELF complex and causes cell lethality, leading to the prevailing concept that NELF-mediated Pol II pausing is essential for cell proliferation. Using separation-of-function mutations, we show here that NELFB function in cell proliferation can be uncoupled from that in Pol II pausing. NELFB mutants sequestered in the cytoplasm and deprived of NELF nuclear function still support cell proliferation and part of the NELFB-dependent transcriptome. Mechanistically, cytoplasmic NELFB physically and functionally interacts with prosurvival signaling kinases, most notably phosphatidylinositol-3-kinase/AKT. Ectopic expression of membrane-tethered phosphatidylinositol-3-kinase/AKT partially bypasses the role of NELFB in cell proliferation, but not Pol II occupancy. Together, these data expand the current understanding of the physiological impact of Pol II pausing and underscore the multiplicity of the biological functions of individual NELF subunits.
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Affiliation(s)
- Haihui Pan
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA.
| | - Xiaolong Cheng
- Department of Genomics & Precision Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA; Center for Genetic Medicine Research, Children's National Hospital, Washington, District of Columbia, USA
| | - Pedro Felipe Gardeazábal Rodríguez
- Department of Anatomy & Cell Biology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Xiaowen Zhang
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Inhee Chung
- Department of Anatomy & Cell Biology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Victor X Jin
- Institute of Health Equity and Cancer Center, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Wei Li
- Department of Genomics & Precision Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA; Center for Genetic Medicine Research, Children's National Hospital, Washington, District of Columbia, USA
| | - Yanfen Hu
- Department of Anatomy & Cell Biology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Rong Li
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA.
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27
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Cao Y, Qin Y, Zhang W, Tian W, Ren Y, Ren J, Wang J, Wang M, Jiang J, Wang Z. Structural basis of the human negative elongation factor NELF-B/C/E ternary complex. Biochem Biophys Res Commun 2023; 677:155-161. [PMID: 37591184 DOI: 10.1016/j.bbrc.2023.08.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 08/09/2023] [Indexed: 08/19/2023]
Abstract
Negative elongation factor (NELF) is a four-subunit transcription elongation factor that mainly functions in maintaining the paused state of RNA polymerase II in eukaryotes. Upon binding to Pol II, NELF works synergistically with DRB sensitivity-inducing factor (DSIF) and inhibits transcription elongation of Pol II, which subsequently retains a stably paused state 20-60 base pairs downstream of the promoter. The promoter-proximal pausing of Pol II caused by NELF is a general mechanism of transcriptional regulation for most signal-responsive genes. To date, structural studies have significantly advanced our understanding of the molecular mechanisms of NELF. However, a high quality structural model clarifying the interaction details of this complex is still lacking. In this study, we solved the high resolution crystal structure of the NELF-B/C/E ternary complex. We observed detailed interactions between subunits and identified residues important for the association between NELF-B and NELF-E. Our work presents a precise model of the NELF complex, which will facilitate our understanding of its in vivo function.
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Affiliation(s)
- Yinghua Cao
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Yan Qin
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Weidi Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Wei Tian
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Yanpeng Ren
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Jiahao Ren
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Junmeng Wang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Meng Wang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China
| | - Junyi Jiang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China.
| | - Zhanxin Wang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing, 100875, China.
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Dollinger R, Deng EB, Schultz J, Wu S, Deorio HR, Gilmour DS. Assessment of the roles of Spt5-nucleic acid contacts in promoter proximal pausing of RNA polymerase II. J Biol Chem 2023; 299:105106. [PMID: 37517697 PMCID: PMC10482750 DOI: 10.1016/j.jbc.2023.105106] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/10/2023] [Accepted: 07/18/2023] [Indexed: 08/01/2023] Open
Abstract
Promoter proximal pausing of RNA polymerase II (Pol II) is a critical transcriptional regulatory mechanism in metazoans that requires the transcription factor DRB sensitivity-inducing factor (DSIF) and the inhibitory negative elongation factor (NELF). DSIF, composed of Spt4 and Spt5, establishes the pause by recruiting NELF to the elongation complex. However, the role of DSIF in pausing beyond NELF recruitment remains unclear. We used a highly purified in vitro system and Drosophila nuclear extract to investigate the role of DSIF in promoter proximal pausing. We identified two domains of Spt5, the KOW4 and NGN domains, that facilitate Pol II pausing. The KOW4 domain promotes pausing through its interaction with the nascent RNA while the NGN domain does so through a short helical motif that is in close proximity to the non-transcribed DNA template strand. Removal of this sequence in Drosophila has a male-specific dominant negative effect. The alpha-helical motif is also needed to support fly viability. We also show that the interaction between the Spt5 KOW1 domain and the upstream DNA helix is required for DSIF association with the Pol II elongation complex. Disruption of the KOW1-DNA interaction is dominant lethal in vivo. Finally, we show that the KOW2-3 domain of Spt5 mediates the recruitment of NELF to the elongation complex. In summary, our results reveal additional roles for DSIF in transcription regulation and identify specific domains important for facilitating Pol II pausing.
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Affiliation(s)
- Roberta Dollinger
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Eilene B Deng
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Josie Schultz
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Sharon Wu
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Haley R Deorio
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA; Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - David S Gilmour
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA.
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29
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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: 3] [Impact Index Per Article: 3.0] [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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30
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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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31
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Zhang J, Hu Z, Chung HH, Tian Y, Lau KW, Ser Z, Lim YT, Sobota RM, Leong HF, Chen BJ, Yeo CJ, Tan SYX, Kang J, Tan DEK, Sou IF, McClurg UL, Lakshmanan M, Vaiyapuri TS, Raju A, Wong ESM, Tergaonkar V, Rajarethinam R, Pathak E, Tam WL, Tan EY, Tee WW. Dependency of NELF-E-SLUG-KAT2B epigenetic axis in breast cancer carcinogenesis. Nat Commun 2023; 14:2439. [PMID: 37117180 PMCID: PMC10147683 DOI: 10.1038/s41467-023-38132-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 04/17/2023] [Indexed: 04/30/2023] Open
Abstract
Cancer cells undergo transcriptional reprogramming to drive tumor progression and metastasis. Using cancer cell lines and patient-derived tumor organoids, we demonstrate that loss of the negative elongation factor (NELF) complex inhibits breast cancer development through downregulating epithelial-mesenchymal transition (EMT) and stemness-associated genes. Quantitative multiplexed Rapid Immunoprecipitation Mass spectrometry of Endogenous proteins (qPLEX-RIME) further reveals a significant rewiring of NELF-E-associated chromatin partners as a function of EMT and a co-option of NELF-E with the key EMT transcription factor SLUG. Accordingly, loss of NELF-E leads to impaired SLUG binding on chromatin. Through integrative transcriptomic and genomic analyses, we identify the histone acetyltransferase, KAT2B, as a key functional target of NELF-E-SLUG. Genetic and pharmacological inactivation of KAT2B ameliorate the expression of EMT markers, phenocopying NELF ablation. Elevated expression of NELF-E and KAT2B is associated with poorer prognosis in breast cancer patients, highlighting the clinical relevance of our findings. Taken together, we uncover a crucial role of the NELF-E-SLUG-KAT2B epigenetic axis in breast cancer carcinogenesis.
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Affiliation(s)
- Jieqiong Zhang
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Republic of Singapore
| | - Zhenhua Hu
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Hwa Hwa Chung
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Yun Tian
- Department of Oncology, Jiangsu Province Hospital of Chinese Medicine, Affiliated Hospital of Nanjing University of Chinese Medicine, 210004, Nanjing, People's Republic of China
| | - Kah Weng Lau
- Department of Pathology, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Republic of Singapore
| | - Zheng Ser
- Functional Proteomics Laboratory, SingMass National Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Yan Ting Lim
- Functional Proteomics Laboratory, SingMass National Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Radoslaw M Sobota
- Functional Proteomics Laboratory, SingMass National Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Hwei Fen Leong
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Benjamin Jieming Chen
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Clarisse Jingyi Yeo
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Shawn Ying Xuan Tan
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Jian Kang
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Dennis Eng Kiat Tan
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Ieng Fong Sou
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Urszula Lucja McClurg
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Manikandan Lakshmanan
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Thamil Selvan Vaiyapuri
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Anandhkumar Raju
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Esther Sook Miin Wong
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Vinay Tergaonkar
- Department of Pathology, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Republic of Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore, 117599, Republic of Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore, 117597, Republic of Singapore
| | - Ravisankar Rajarethinam
- Advanced Molecular Pathology Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Elina Pathak
- Genome Institute of Singapore, Agency for Science, Technology and Research (A*STAR), 60 Biopolis Drive, Genome, Singapore, 138672, Republic of Singapore
| | - Wai Leong Tam
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore, 117599, Republic of Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore, 117597, Republic of Singapore
- Genome Institute of Singapore, Agency for Science, Technology and Research (A*STAR), 60 Biopolis Drive, Genome, Singapore, 138672, Republic of Singapore
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Republic of Singapore
| | - Ern Yu Tan
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
- Department of General Surgery, Tan Tock Seng Hospital, Singapore, 308433, Republic of Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Republic of Singapore
| | - Wee-Wei Tee
- Chromatin Dynamics and Disease Epigenetics Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore.
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Republic of Singapore.
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore, 117599, Republic of Singapore.
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32
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Marwarha G, Slagsvold KH, Høydal MA. NF-κB Transcriptional Activity Indispensably Mediates Hypoxia–Reoxygenation Stress-Induced microRNA-210 Expression. Int J Mol Sci 2023; 24:ijms24076618. [PMID: 37047592 PMCID: PMC10095479 DOI: 10.3390/ijms24076618] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
Ischemia–reperfusion (I-R) injury is a cardinal pathophysiological hallmark of ischemic heart disease (IHD). Despite significant advances in the understanding of what causes I-R injury and hypoxia–reoxygenation (H-R) stress, viable molecular strategies that could be targeted for the treatment of the deleterious biochemical pathways activated during I-R remain elusive. The master hypoxamiR, microRNA-210 (miR-210), is a major determinant of protective cellular adaptation to hypoxia stress but exacerbates apoptotic cell death during cellular reoxygenation. While the hypoxia-induced transcriptional up-regulation of miR-210 is well delineated, the cellular mechanisms and molecular entities that regulate the transcriptional induction of miR-210 during the cellular reoxygenation phase have not been elucidated yet. Herein, in immortalized AC-16 cardiomyocytes, we delineated the indispensable role of the ubiquitously expressed transcription factor, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) in H-R-induced miR-210 expression during cellular reoxygenation. Using dominant negative and dominant active expression vectors encoding kinases to competitively inhibit NF-κB activation, we elucidated NF-κB activation as a significant mediator of H-R-induced miR-210 expression. Ensuing molecular assays revealed a direct NF-κB-mediated transcriptional up-regulation of miR-210 expression in response to the H-R challenge that is characterized by the NF-κB-mediated reorchestration of the entire repertoire of histone modification changes that are a signatory of a permissive actively transcribed miR-210 promoter. Our study confers a novel insight identifying NF-κB as a potential novel molecular target to combat H-R-elicited miR-210 expression that fosters augmented cardiomyocyte cell death.
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Affiliation(s)
- Gurdeep Marwarha
- Group of Molecular and Cellular Cardiology, Department of Circulation and Medical Imaging, Faculty of Medicine and Health, Norwegian University of Science and Technology (NTNU), 7034 Trondheim, Norway
| | - Katrine Hordnes Slagsvold
- Group of Molecular and Cellular Cardiology, Department of Circulation and Medical Imaging, Faculty of Medicine and Health, Norwegian University of Science and Technology (NTNU), 7034 Trondheim, Norway
- Department of Cardiothoracic Surgery, St. Olavs University Hospital, 7030 Trondheim, Norway
| | - Morten Andre Høydal
- Group of Molecular and Cellular Cardiology, Department of Circulation and Medical Imaging, Faculty of Medicine and Health, Norwegian University of Science and Technology (NTNU), 7034 Trondheim, Norway
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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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Zhang P, Tan P, Zhang L, Zhu W, Chen R, Wang L, Xu D. A Comparative Study on Growth Performance, Body Composition, and Liver Tissue Metabolism Rearing on Soybean Lecithin-Enriched Artemia Nauplii and Microdiet in Rock Bream ( Oplegnathus fasciatus) Larvae. AQUACULTURE NUTRITION 2023; 2023:5545898. [PMID: 36967811 PMCID: PMC10036177 DOI: 10.1155/2023/5545898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/26/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
This study is aimed at establishing optimal soybean lecithin (SL) enrichment protocols in Artemia nauplii and at comparing the growth performance, body composition, and liver tissue metabolism in rock bream (Oplegnathus fasciatus) larvae reared on SL-enriched Artemia nauplii or SL-enriched microdiet (MD). The enrichment protocol experiment results indicated 12 h enrichment, and 10 g SL/m3 seawater could obtain desirable results. Rock bream larvae (25 days posthatching (dph)) were fed Artemia nauplii or MD for 30 days with three replicates. At stage 1 (larval 25-40 dph), significantly higher growth performance was observed in larvae fed the live prey (P < 0.05). Conversely, at stage 2 (41-55 dph), feeding with MD significantly increased larval standard length, and specific growth rate compared with those of larvae fed live prey. Larvae fed a MD showed decreased lipolysis-related lipase activity as well as decreased amino acid catabolism-related alanine aminotransferase and aspartate aminotransferase enzyme activities in liver tissue. RNA sequencing revealed that feeding with the MD primarily increased the expression of lipogenesis-related genes and protein translation-related gene expression in the liver tissue. Notably, feeding with MD significantly increased ribosome biogenesis-related genes as well as mitochondria synthesis-related gene expression, indicating a high protein anabolism rate and high energy production in liver tissue. In conclusion, 10 g SL/m3 seawater and 12 h could effectively enrich SL in Artemia nauplii. Retard weaning onto MD led to lower growth performance, which was likely due to the diversity of lipid and protein metabolism.
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Affiliation(s)
- Pian Zhang
- Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China
- Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316022, China
| | - Peng Tan
- Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316022, China
| | - Lei Zhang
- Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China
- Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316022, China
| | - Wenliang Zhu
- Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China
- Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316022, China
| | - Ruiyi Chen
- Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316022, China
| | - Ligai Wang
- Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316022, China
| | - Dongdong Xu
- Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316022, 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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Fujinaga K, Huang F, Peterlin BM. P-TEFb: The master regulator of transcription elongation. Mol Cell 2023; 83:393-403. [PMID: 36599353 PMCID: PMC9898187 DOI: 10.1016/j.molcel.2022.12.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/10/2022] [Accepted: 12/08/2022] [Indexed: 01/05/2023]
Abstract
The positive transcription elongation factor b (P-TEFb) is composed of cyclins T1 or T2 and cyclin-dependent kinase 9 that regulate the elongation phase of transcription by RNA polymerase II. By antagonizing negative elongation factors and phosphorylating the C-terminal domain of RNA polymerase II, P-TEFb facilitates the elongation and co-transcriptional processing of nascent transcripts. This step is critical for the expression of most eukaryotic genes. In growing cells, P-TEFb is regulated negatively by its reversible associations with HEXIM1/2 in the 7SK snRNP and positively by a number of transcription factors, as well as the super elongation complex. In resting cells, P-TEFb falls apart, and cyclin T1 is degraded by the proteasome. This complex regulation of P-TEFb has evolved for the precise temporal and spatial regulation of gene expression in the organism. Its dysregulation contributes to inflammatory and neoplastic conditions.
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Affiliation(s)
- Koh Fujinaga
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA.
| | - Fang Huang
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA
| | - B Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA.
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MDC1 maintains active elongation complexes of RNA polymerase II. Cell Rep 2023; 42:111979. [PMID: 36640322 DOI: 10.1016/j.celrep.2022.111979] [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: 12/14/2021] [Revised: 10/04/2022] [Accepted: 12/23/2022] [Indexed: 01/13/2023] Open
Abstract
The role of MDC1 in the DNA damage response has been extensively studied; however, its impact on other cellular processes is not well understood. Here, we describe the role of MDC1 in transcription as a regulator of RNA polymerase II (RNAPII). Depletion of MDC1 causes a genome-wide reduction in the abundance of actively engaged RNAPII elongation complexes throughout the gene body of protein-encoding genes under unperturbed conditions. Decreased engaged RNAPII subsequently alters the assembly of the spliceosome complex on chromatin, leading to changes in pre-mRNA splicing. Mechanistically, the S/TQ domain of MDC1 modulates RNAPII-mediated transcription. Upon genotoxic stress, MDC1 promotes the abundance of engaged RNAPII complexes at DNA breaks, thereby stimulating nascent transcription at the damaged sites. Of clinical relevance, cancer cells lacking MDC1 display hypersensitivity to RNAPII inhibitors. Overall, we unveil a role of MDC1 in RNAPII-mediated transcription with potential implications for cancer treatment.
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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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39
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Watts JA, Grunseich C, Rodriguez Y, Liu Y, Li D, Burdick J, Bruzel A, Crouch RJ, Mahley RW, Wilson S, Cheung V. A common transcriptional mechanism involving R-loop and RNA abasic site regulates an enhancer RNA of APOE. Nucleic Acids Res 2022; 50:12497-12514. [PMID: 36453989 PMCID: PMC9757052 DOI: 10.1093/nar/gkac1107] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/30/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022] Open
Abstract
RNA is modified by hundreds of chemical reactions and folds into innumerable shapes. However, the regulatory role of RNA sequence and structure and how dysregulation leads to diseases remain largely unknown. Here, we uncovered a mechanism where RNA abasic sites in R-loops regulate transcription by pausing RNA polymerase II. We found an enhancer RNA, AANCR, that regulates the transcription and expression of apolipoprotein E (APOE). In some human cells such as fibroblasts, AANCR is folded into an R-loop and modified by N-glycosidic cleavage; in this form, AANCR is a partially transcribed nonfunctional enhancer and APOE is not expressed. In contrast, in other cell types including hepatocytes and under stress, AANCR does not form a stable R-loop as its sequence is not modified, so it is transcribed into a full-length enhancer that promotes APOE expression. DNA sequence variants in AANCR are associated significantly with APOE expression and Alzheimer's Disease, thus AANCR is a modifier of Alzheimer's Disease. Besides AANCR, thousands of noncoding RNAs are regulated by abasic sites in R-loops. Together our data reveal the essentiality of the folding and modification of RNA in cellular regulation and demonstrate that dysregulation underlies common complex diseases such as Alzheimer's disease.
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Affiliation(s)
- Jason A Watts
- Department of Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Epigenetics and Stem Cell Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Christopher Grunseich
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yesenia Rodriguez
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yaojuan Liu
- Department of Pediatrics and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dongjun Li
- Department of Pediatrics and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Joshua T Burdick
- Department of Pediatrics and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alan Bruzel
- Department of Pediatrics and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Robert J Crouch
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert W Mahley
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
- Departments of Pathology and Medicine, University of California, San Francisco, CA, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Vivian G Cheung
- Department of Pediatrics and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
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Cheng F, Zheng W, Liu C, Barbuti PA, Yu-Taeger L, Casadei N, Huebener-Schmid J, Admard J, Boldt K, Junger K, Ueffing M, Houlden H, Sharma M, Kruger R, Grundmann-Hauser K, Ott T, Riess O. Intronic enhancers of the human SNCA gene predominantly regulate its expression in brain in vivo. SCIENCE ADVANCES 2022; 8:eabq6324. [PMID: 36417521 PMCID: PMC9683720 DOI: 10.1126/sciadv.abq6324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Evidence from patients with Parkinson's disease (PD) and our previously reported α-synuclein (SNCA) transgenic rat model support the idea that increased SNCA protein is a substantial risk factor of PD pathogenesis. However, little is known about the transcription control of the human SNCA gene in the brain in vivo. Here, we identified that the DYT6 gene product THAP1 (THAP domain-containing apoptosis-associated protein 1) and its interaction partner CTCF (CCCTC-binding factor) act as transcription regulators of SNCA. THAP1 controls SNCA intronic enhancers' activities, while CTCF regulates its enhancer-promoter loop formation. The SNCA intronic enhancers present neurodevelopment-dependent activities and form enhancer clusters similar to "super-enhancers" in the brain, in which the PD-associated single-nucleotide polymorphisms are enriched. Deletion of the SNCA intronic enhancer clusters prevents the release of paused RNA polymerase II from its promoter and subsequently reduces its expression drastically in the brain, which may provide new therapeutic approaches to prevent its accumulation and thus related neurodegenerative diseases defined as synucleinopathies.
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Affiliation(s)
- Fubo Cheng
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
- Centre for Rare Diseases, University Tuebingen, Tuebingen, Germany
| | - Wenxu Zheng
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- Institute for Ophthalmic Research Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Chang Liu
- Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Peter Antony Barbuti
- Translational Neuroscience, Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belvaux, Luxembourg
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Libo Yu-Taeger
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- Department of Human Genetics, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Nicolas Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- NGS Competence Center Tuebingen, Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Jeannette Huebener-Schmid
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- Centre for Rare Diseases, University Tuebingen, Tuebingen, Germany
| | - Jakob Admard
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- NGS Competence Center Tuebingen, Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Karsten Boldt
- Institute for Ophthalmic Research Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Katrin Junger
- Institute for Ophthalmic Research Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Marius Ueffing
- Institute for Ophthalmic Research Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Manu Sharma
- Centre for Genetic Epidemiology, Institute for Clinical Epidemiology and Applied Biometry, University of Tuebingen, Tuebingen, Germany
| | - Rejko Kruger
- Translational Neuroscience, Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belvaux, Luxembourg
- Transversal Translational Medicine, Luxembourg Institute of Health (LIH), Strassen, Luxembourg
- Parkinson Research Clinic, Centre Hospitalier de Luxembourg (CHL), Luxembourg, Luxembourg
| | - Kathrin Grundmann-Hauser
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- Centre for Rare Diseases, University Tuebingen, Tuebingen, Germany
| | - Thomas Ott
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- IZKF-Core Facility Transgenic Animals, University Clinics Tuebingen, Tuebingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- Centre for Rare Diseases, University Tuebingen, Tuebingen, Germany
- NGS Competence Center Tuebingen, Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
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41
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The Paf1 complex is required for RNA polymerase II removal in response to DNA damage. Proc Natl Acad Sci U S A 2022; 119:e2207332119. [PMID: 36161924 DOI: 10.1073/pnas.2207332119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rpb1, the largest subunit of RNA polymerase II (RNAPII), is rapidly polyubiquitinated and degraded in response to DNA damage; this process is considered to be a "mechanism of last resort'' employed by cells. The underlying mechanism of this process remains elusive. Here, we uncovered a previously uncharacterized multistep pathway in which the polymerase-associated factor 1 (Paf1) complex (PAF1C, composed of the subunits Ctr9, Paf1, Leo1, Cdc73, and Rtf1) is involved in regulating the RNAPII pool by stimulating Elongin-Cullin E3 ligase complex-mediated Rpb1 polyubiquitination and subsequent degradation by the proteasome following DNA damage. Mechanistically, Spt5 is dephosphorylated following DNA damage, thereby weakening the interaction between the Rtf1 subunit and Spt5, which might be a key step in initiating Rpb1 degradation. Next, Rad26 is loaded onto stalled RNAPII to replace the Spt4/Spt5 complex in an RNAPII-dependent manner and, in turn, recruits more PAF1C to DNA lesions via the binding of Rad26 to the Leo1 subunit. Importantly, the PAF1C, assembled in a Ctr9-mediated manner, coordinates with Rad26 to localize the Elongin-Cullin complex on stalled RNAPII, thereby inducing RNAPII removal, in which the heterodimer Paf1/Leo1 and the subunit Cdc73 play important roles. Together, our results clearly revealed a new role of the intact PAF1C in regulating the RNAPII pool in response to DNA damage.
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Aoi Y, Shah AP, Ganesan S, Soliman SHA, Cho BK, Goo YA, Kelleher NL, Shilatifard A. SPT6 functions in transcriptional pause/release via PAF1C recruitment. Mol Cell 2022; 82:3412-3423.e5. [PMID: 35973425 PMCID: PMC9714687 DOI: 10.1016/j.molcel.2022.06.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 05/11/2022] [Accepted: 06/29/2022] [Indexed: 01/24/2023]
Abstract
It is unclear how various factors functioning in the transcriptional elongation by RNA polymerase II (RNA Pol II) cooperatively regulate pause/release and productive elongation in living cells. Using an acute protein-depletion approach, we report that SPT6 depletion results in the release of paused RNA Pol II into gene bodies through an impaired recruitment of PAF1C. Short genes demonstrate a release with increased mature transcripts, whereas long genes are released but fail to yield mature transcripts, due to a reduced processivity resulting from both SPT6 and PAF1C loss. Unexpectedly, SPT6 depletion causes an association of NELF with the elongating RNA Pol II on gene bodies, without any observed functional significance on transcriptional elongation pattern, arguing against a role for NELF in keeping RNA Pol II in the paused state. Furthermore, SPT6 depletion impairs heat-shock-induced pausing, pointing to a role for SPT6 in regulating RNA Pol II pause/release through PAF1C recruitment.
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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
| | - Avani P Shah
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sheetal Ganesan
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Shimaa H A Soliman
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Byoung-Kyu Cho
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Proteomics Center of Excellence, Northwestern University, Evanston, IL 60611, USA
| | - Young Ah Goo
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Proteomics Center of Excellence, Northwestern University, Evanston, IL 60611, USA
| | - Neil L Kelleher
- Simpson Querrey Institute for Epigenetics, Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Proteomics Center of Excellence, Northwestern University, Evanston, 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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Whelan M, Pelchat M. Role of RNA Polymerase II Promoter-Proximal Pausing in Viral Transcription. Viruses 2022; 14:v14092029. [PMID: 36146833 PMCID: PMC9503719 DOI: 10.3390/v14092029] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/09/2022] [Accepted: 09/11/2022] [Indexed: 11/16/2022] Open
Abstract
The promoter-proximal pause induced by the binding of the DRB sensitivity-inducing factor (DSIF) and the negative elongation factor (NELF) to RNAP II is a key step in the regulation of metazoan gene expression. It helps maintain a permissive chromatin landscape and ensures a quick transcriptional response from stimulus-responsive pathways such as the innate immune response. It is also involved in the biology of several RNA viruses such as the human immunodeficiency virus (HIV), the influenza A virus (IAV) and the hepatitis delta virus (HDV). HIV uses the pause as one of its mechanisms to enter and maintain latency, leading to the creation of viral reservoirs resistant to antiretrovirals. IAV, on the other hand, uses the pause to acquire the capped primers necessary to initiate viral transcription through cap-snatching. Finally, the HDV RNA genome is transcribed directly by RNAP II and requires the small hepatitis delta antigen to displace NELF from the polymerase and overcome the transcriptional block caused by RNAP II promoter-proximal pausing. In this review, we will discuss the RNAP II promoter-proximal pause and the roles it plays in the life cycle of RNA viruses such as HIV, IAV and HDV.
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RNA Polymerase II “Pause” Prepares Promoters for Upcoming Transcription during Drosophila Development. Int J Mol Sci 2022; 23:ijms231810662. [PMID: 36142573 PMCID: PMC9503990 DOI: 10.3390/ijms231810662] [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: 08/12/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022] Open
Abstract
According to previous studies, during Drosophila embryogenesis, the recruitment of RNA polymerase II precedes active gene transcription. This work is aimed at exploring whether this mechanism is used during Drosophila metamorphosis. In addition, the composition of the RNA polymerase II “paused” complexes associated with promoters at different developmental stages are described in detail. For this purpose, we performed ChIP-Seq analysis using antibodies for various modifications of RNA polymerase II (total, Pol II CTD Ser5P, and Pol II CTD Ser2P) as well as for subunits of the NELF, DSIF, and PAF complexes and Brd4/Fs(1)h that control transcription elongation. We found that during metamorphosis, similar to mid-embryogenesis, the promoters were bound by RNA polymerase II in the “paused” state, preparing for activation at later stages of development. During mid-embryogenesis, RNA polymerase II in a “pause” state was phosphorylated at Ser5 and Ser2 of Pol II CTD and bound the NELF, DSIF, and PAF complexes, but not Brd4/Fs(1)h. During metamorphosis, the “paused” RNA polymerase II complex included Brd4/Fs(1)h in addition to NELF, DSIF, and PAF. The RNA polymerase II in this complex was phosphorylated at Ser5 of Pol II CTD, but not at Ser2. These results indicate that, during mid-embryogenesis, RNA polymerase II stalls in the “post-pause” state, being phosphorylated at Ser2 of Pol II CTD (after the stage of p-TEFb action). During metamorphosis, the “pause” mechanism is closer to classical promoter-proximal pausing and is characterized by a low level of Pol II CTD Ser2P.
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Abuhashem A, Chivu AG, Zhao Y, Rice EJ, Siepel A, Danko CG, Hadjantonakis AK. RNA Pol II pausing facilitates phased pluripotency transitions by buffering transcription. Genes Dev 2022; 36:gad.349565.122. [PMID: 35981753 PMCID: PMC9480856 DOI: 10.1101/gad.349565.122] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 07/18/2022] [Indexed: 01/03/2023]
Abstract
Promoter-proximal RNA Pol II pausing is a critical step in transcriptional control. Pol II pausing has been predominantly studied in tissue culture systems. While Pol II pausing has been shown to be required for mammalian development, the phenotypic and mechanistic details of this requirement are unknown. Here, we found that loss of Pol II pausing stalls pluripotent state transitions within the epiblast of the early mouse embryo. Using Nelfb -/- mice and a NELFB degron mouse pluripotent stem cell model, we show that embryonic stem cells (ESCs) representing the naïve state of pluripotency successfully initiate a transition program but fail to balance levels of induced and repressed genes and enhancers in the absence of NELF. We found an increase in chromatin-associated NELF during transition from the naïve to later pluripotent states. Overall, our work defines the acute and long-term molecular consequences of NELF loss and reveals a role for Pol II pausing in the pluripotency continuum as a modulator of cell state transitions.
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Affiliation(s)
- Abderhman Abuhashem
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, New York 10065, USA
- Biochemistry Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York 10065, USA
| | - Alexandra G Chivu
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
| | - Yixin Zhao
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Edward J Rice
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | - Adam Siepel
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Charles G Danko
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | - Anna-Katerina Hadjantonakis
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
- Biochemistry Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York 10065, USA
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Pham VV, Gao M, Meagher JL, Smith JL, D'Souza VM. A structure-based mechanism for displacement of the HEXIM adapter from 7SK small nuclear RNA. Commun Biol 2022; 5:819. [PMID: 35970937 PMCID: PMC9378691 DOI: 10.1038/s42003-022-03734-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 07/19/2022] [Indexed: 11/09/2022] Open
Abstract
Productive transcriptional elongation of many cellular and viral mRNAs requires transcriptional factors to extract pTEFb from the 7SK snRNP by modulating the association between HEXIM and 7SK snRNA. In HIV-1, Tat binds to 7SK by displacing HEXIM. However, without the structure of the 7SK-HEXIM complex, the constraints that must be overcome for displacement remain unknown. Furthermore, while structure details of the TatNL4-3-7SK complex have been elucidated, it is unclear how subtypes with more HEXIM-like Tat sequences accomplish displacement. Here we report the structures of HEXIM, TatG, and TatFin arginine rich motifs in complex with the apical stemloop-1 of 7SK. While most interactions between 7SK with HEXIM and Tat are similar, critical differences exist that guide function. First, the conformational plasticity of 7SK enables the formation of three different base pair configurations at a critical remodeling site, which allows for the modulation required for HEXIM binding and its subsequent displacement by Tat. Furthermore, the specific sequence variations observed in various Tat subtypes all converge on remodeling 7SK at this region. Second, we show that HEXIM primes its own displacement by causing specific local destabilization upon binding - a feature that is then exploited by Tat to bind 7SK more efficiently.
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Affiliation(s)
- Vincent V Pham
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Michael Gao
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jennifer L Meagher
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Janet L Smith
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Victoria M D'Souza
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA.
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Abstract
Enhancers confer precise spatiotemporal patterns of gene expression in response to developmental and environmental stimuli. Over the last decade, the transcription of enhancer RNAs (eRNAs) – nascent RNAs transcribed from active enhancers – has emerged as a key factor regulating enhancer activity. eRNAs are relatively short-lived RNA species that are transcribed at very high rates but also quickly degraded. Nevertheless, eRNAs are deeply intertwined within enhancer regulatory networks and are implicated in a number of transcriptional control mechanisms. Enhancers show changes in function and sequence over evolutionary time, raising questions about the relationship between enhancer sequences and eRNA function. Moreover, the vast majority of single nucleotide polymorphisms associated with human complex diseases map to the non-coding genome, with causal disease variants enriched within enhancers. In this Primer, we survey the diverse roles played by eRNAs in enhancer-dependent gene expression, evaluating different models for eRNA function. We also explore questions surrounding the genetic conservation of enhancers and how this relates to eRNA function and dysfunction. Summary: This Primer evaluates the ideas that underpin developing models for eRNA function, exploring cases in which perturbed eRNA function contributes to disease.
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Affiliation(s)
- Laura J. Harrison
- Molecular and Cellular Biology, School of Biosciences, Sheffield Institute For Nucleic Acids, The University of Sheffield, Firth Court, Western Bank , Sheffield S10 2TN , UK
| | - Daniel Bose
- Molecular and Cellular Biology, School of Biosciences, Sheffield Institute For Nucleic Acids, The University of Sheffield, Firth Court, Western Bank , Sheffield S10 2TN , UK
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Sawai S, Wong PF, Ramasamy TS. Hypoxia-regulated microRNAs: the molecular drivers of tumor progression. Crit Rev Biochem Mol Biol 2022; 57:351-376. [PMID: 35900938 DOI: 10.1080/10409238.2022.2088684] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hypoxia is a common feature of the tumor microenvironment (TME) of nearly all solid tumors, leading to therapeutic failure. The changes in stiffness of the extracellular matrix (ECM), pH gradients, and chemical balance that contribute to multiple cancer hallmarks are closely regulated by intratumoral oxygen tension via its primary mediators, hypoxia-inducible factors (HIFs). HIFs, especially HIF-1α, influence these changes in the TME by regulating vital cancer-associated signaling pathways and cellular processes including MAPK/ERK, NF-κB, STAT3, PI3K/Akt, Wnt, p53, and glycolysis. Interestingly, research has revealed the involvement of epigenetic regulation by hypoxia-regulated microRNAs (HRMs) of downstream target genes involved in these signaling. Through literature search and analysis, we identified 48 HRMs that have a functional role in the regulation of 5 key cellular processes: proliferation, metabolism, survival, invasion and migration, and immunoregulation in various cancers in hypoxic condition. Among these HRMs, 17 were identified to be directly associated with HIFs which include miR-135b, miR-145, miR-155, miR-181a, miR-182, miR-210, miR-224, miR-301a, and miR-675-5p as oncomiRNAs, and miR-100-5p, miR-138, miR-138-5p, miR-153, miR-22, miR-338-3p, miR-519d-3p, and miR-548an as tumor suppressor miRNAs. These HRMs serve as a potential lead in the development of miRNA-based targeted therapy for advanced solid tumors. Future development of combined HIF-targeted and miRNA-targeted therapy is possible, which requires comprehensive profiling of HIFs-HRMs regulatory network, and improved formula of the delivery vehicles to enhance the therapeutic kinetics of the targeted cancer therapy (TCT) moving forward.
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Affiliation(s)
- Sakunie Sawai
- Stem Cell Biology Laboratory, Department of Molecular Medicine, Faculty of Medicine, Universiti Malaya, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Pooi-Fong Wong
- Department of Pharmacology, Faculty of Medicine, Universiti Malaya, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Thamil Selvee Ramasamy
- Stem Cell Biology Laboratory, Department of Molecular Medicine, Faculty of Medicine, Universiti Malaya, Wilayah Persekutuan Kuala Lumpur, Malaysia
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Guo X, Chen H, Zhou Y, Shen L, Wu S, Chen Y. Cyclin-dependent kinase inhibition and its intersection with immunotherapy in breast cancer: more than CDK4/6 inhibition. Expert Opin Investig Drugs 2022; 31:933-944. [PMID: 35786092 DOI: 10.1080/13543784.2022.2097067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Cyclin-dependent kinase (CDK) 4/6 inhibitors (CDK4/6i) have had clinical success in treating hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer. Notably, CDK4/6i have expanded to the neoadjuvant setting for early breast cancer and other cancer types and potently synergize with immunotherapy. Other CDKs, including CDK7, CDK9, and CDK12/13, mainly function in transcriptional processes as well as cell cycle regulation, RNA splicing, and DNA damage response. Inhibiting these CDKs aids in suppressing tumors, reversing drug resistance, increasing drug sensitivity, and enhancing anti-tumor immunity in breast cancer. AREAS COVERED We reviewed the applications of CDK4/6i, CDK7i, CDK9i and CDK12/13i for various breast cancer subtypes and their potentials for combination with immunotherapy. A literature search of PubMed, Embase, and Web of Science was conducted in April 2022. EXPERT OPINION The use of CDK4/6i represents a major milestone in breast cancer treatment. Moreover, transcription-related CDKs play critical roles in tumor development and are promising therapeutic targets for breast cancer. Some relevant clinical studies are underway. More specific and efficient CDKis will undoubtedly be developed and clinically tested. Characterization of their immune-priming effects will promote the development of combination therapies consisting of CDKi and immunotherapy.
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Affiliation(s)
- Xianan Guo
- Department of Breast Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Huihui Chen
- Department of Breast Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yunxiang Zhou
- Department of Breast Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Lu Shen
- Department of Breast Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shijie Wu
- Department of Breast Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yiding Chen
- Department of Breast Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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Gala HP, Saha D, Venugopal N, Aloysius A, Purohit G, Dhawan J. A transcriptionally repressed quiescence program is associated with paused RNAPII and is poised for cell cycle reentry. J Cell Sci 2022; 135:275901. [PMID: 35781573 DOI: 10.1242/jcs.259789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 06/27/2022] [Indexed: 11/20/2022] Open
Abstract
Adult stem cells persist in mammalian tissues by entering a state of reversible quiescence/ G0, associated with low transcription. Using cultured myoblasts and muscle stem cells, we report that in G0, global RNA content and synthesis are substantially repressed, correlating with decreased RNA Polymerase II (RNAPII) expression and activation. Integrating RNAPII occupancy and transcriptome profiling, we identify repressed networks and a role for promoter-proximal RNAPII pausing in G0. Strikingly, RNAPII shows enhanced pausing in G0 on repressed genes encoding regulators of RNA biogenesis (Nucleolin, Rps24, Ctdp1); release of pausing is associated with their increased expression in G1. Knockdown of these transcripts in proliferating cells leads to induction of G0 markers, confirming the importance of their repression in establishment of G0. A targeted screen of RNAPII regulators revealed that knockdown of Aff4 (positive regulator of elongation) unexpectedly enhances expression of G0-stalled genes and hastens S phase; NELF, a regulator of pausing appears to be dispensable. We propose that RNAPII pausing contributes to transcriptional control of a subset of G0-repressed genes to maintain quiescence and impacts the timing of the G0-G1 transition.
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Affiliation(s)
- Hardik P Gala
- Centre for Cellular and Molecular Biology, Hyderabad, 500007, India.,Institute for Stem Cell Science and Regenerative Medicine, Bangalore, 560065, India
| | - Debarya Saha
- Centre for Cellular and Molecular Biology, Hyderabad, 500007, India
| | - Nisha Venugopal
- Centre for Cellular and Molecular Biology, Hyderabad, 500007, India.,Institute for Stem Cell Science and Regenerative Medicine, Bangalore, 560065, India
| | - Ajoy Aloysius
- Centre for Cellular and Molecular Biology, Hyderabad, 500007, India.,Institute for Stem Cell Science and Regenerative Medicine, Bangalore, 560065, India.,National Center for Biological Sciences, Bangalore, 560065, India
| | - Gunjan Purohit
- Centre for Cellular and Molecular Biology, Hyderabad, 500007, India
| | - Jyotsna Dhawan
- Centre for Cellular and Molecular Biology, Hyderabad, 500007, India.,Institute for Stem Cell Science and Regenerative Medicine, Bangalore, 560065, India
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