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Li N, Ma J, Fu H, Yang Z, Xu C, Li H, Zhao Y, Zhao Y, Chen S, Gou L, Zhang X, Zhang S, Li M, Hou X, Zhang L, Lu Y. Four Parallel Pathways in T4 Ligase-Catalyzed Repair of Nicked DNA with Diverse Bending Angles. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2401150. [PMID: 38582512 PMCID: PMC11220639 DOI: 10.1002/advs.202401150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/08/2024] [Indexed: 04/08/2024]
Abstract
The structural diversity of biological macromolecules in different environments contributes complexity to enzymological processes vital for cellular functions. Fluorescence resonance energy transfer and electron microscopy are used to investigate the enzymatic reaction of T4 DNA ligase catalyzing the ligation of nicked DNA. The data show that both the ligase-AMP complex and the ligase-AMP-DNA complex can have four conformations. This finding suggests the parallel occurrence of four ligation reaction pathways, each characterized by specific conformations of the ligase-AMP complex that persist in the ligase-AMP-DNA complex. Notably, these complexes have DNA bending angles of ≈0°, 20°, 60°, or 100°. The mechanism of parallel reactions challenges the conventional notion of simple sequential reaction steps occurring among multiple conformations. The results provide insights into the dynamic conformational changes and the versatile attributes of T4 DNA ligase and suggest that the parallel multiple reaction pathways may correspond to diverse T4 DNA ligase functions. This mechanism may potentially have evolved as an adaptive strategy across evolutionary history to navigate complex environments.
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Affiliation(s)
- Na Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Jianbing Ma
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190China
| | - Hang Fu
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190China
- University of Chinese Academy of SciencesBeijing100049China
- Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiang325011China
| | - Zhiwei Yang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Chunhua Xu
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190China
| | - Haihong Li
- College of Life SciencesNorthwest A&F UniversityYangling712100China
| | - Yimin Zhao
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Yizhen Zhao
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Shuyu Chen
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Lu Gou
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Xinghua Zhang
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Shengli Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Ming Li
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190China
- University of Chinese Academy of SciencesBeijing100049China
- Songshan Lake Materials LaboratoryDongguanGuangdong523808China
| | - Ximiao Hou
- College of Life SciencesNorthwest A&F UniversityYangling712100China
| | - Lei Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterSchool of PhysicsXi'an Jiaotong UniversityXi'an710049China
| | - Ying Lu
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190China
- University of Chinese Academy of SciencesBeijing100049China
- Songshan Lake Materials LaboratoryDongguanGuangdong523808China
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2
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Sims AA, Gurkar AU. DNA damage-induced stalling of transcription drives aging through gene expression imbalance. DNA Repair (Amst) 2023; 125:103483. [PMID: 36921370 DOI: 10.1016/j.dnarep.2023.103483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023]
Abstract
Age-related changes in gene expression have long been examined to understand the biology of aging. The hallmarks of aging are biological processes known to be associated with aging, but whether there is a unifying driver of these attributes, is not well understood. With the advent of technology over the last few years, it is quite clear that aging leads to global decline in transcription. In this Perspective, we highlight a new study in Nature Genetics that aimed to determine why global transcription rate reduces with age and how this phenomenon is the driver that interconnects multiple hallmarks of aging. This study recognizes that age-related accumulation of DNA damage, particularly transcription-blocking lesions, stalls RNA polymerase. This phenomenon affects longer genes leading to a gradual loss of transcription and skewing the transcriptome. In order to design a successful aging intervention, future work will be needed to test how some promising therapies in pre-clinical trials target affect transcriptional rate.
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Affiliation(s)
- Austin A Sims
- Aging Institute of UPMC and the University of Pittsburgh School of Medicine, 100 Technology Dr, Pittsburgh, PA 15219, USA
| | - Aditi U Gurkar
- Aging Institute of UPMC and the University of Pittsburgh School of Medicine, 100 Technology Dr, Pittsburgh, PA 15219, USA.
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3
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Cermakova K, Hodges HC. Interaction modules that impart specificity to disordered protein. Trends Biochem Sci 2023; 48:477-490. [PMID: 36754681 PMCID: PMC10106370 DOI: 10.1016/j.tibs.2023.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 02/09/2023]
Abstract
Intrinsically disordered regions (IDRs) are especially enriched among proteins that regulate chromatin and transcription. As a result, mechanisms that influence specificity of IDR-driven interactions have emerged as exciting unresolved issues for understanding gene regulation. We review the molecular elements frequently found within IDRs that confer regulatory specificity. In particular, we summarize the differing roles of disordered low-complexity regions (LCRs) and short linear motifs (SLiMs) towards selective nuclear regulation. Examination of IDR-driven interactions highlights SLiMs as organizers of selectivity, with widespread roles in gene regulation and integration of cellular signals. Analysis of recurrent interactions between SLiMs and folded domains suggests diverse avenues for SLiMs to influence phase-separated condensates and highlights opportunities to manipulate these interactions for control of biological activity.
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Affiliation(s)
- Katerina Cermakova
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA
| | - H Courtney Hodges
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA; Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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4
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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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5
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Stepien A, Dolata J, Gulanicz T, Bielewicz D, Bajczyk M, Smolinski DJ, Szweykowska-Kulinska Z, Jarmolowski A. Chromatin-associated microprocessor assembly is regulated by the U1 snRNP auxiliary protein PRP40. THE PLANT CELL 2022; 34:4920-4935. [PMID: 36087009 PMCID: PMC9709975 DOI: 10.1093/plcell/koac278] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 09/05/2022] [Indexed: 06/01/2023]
Abstract
In plants, microRNA (miRNA) biogenesis involves cotranscriptional processing of RNA polymerase II (RNAPII)-generated primary transcripts by a multi-protein complex termed the microprocessor. Here, we report that Arabidopsis (Arabidopsis thaliana) PRE-MRNA PROCESSING PROTEIN 40 (PRP40), the U1 snRNP auxiliary protein, positively regulates the recruitment of SERRATE, a core component of the plant microprocessor, to miRNA genes. The association of DICER-LIKE1 (DCL1), the microprocessor endoribonuclease, with chromatin was altered in prp40ab mutant plants. Impaired cotranscriptional microprocessor assembly was accompanied by RNAPII accumulation at miRNA genes and retention of miRNA precursors at their transcription sites in the prp40ab mutant plants. We show that cotranscriptional microprocessor assembly, regulated by AtPRP40, positively affects RNAPII transcription of miRNA genes and is important to reach the correct levels of produced miRNAs.
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Affiliation(s)
| | | | | | | | - Mateusz Bajczyk
- Department of Gene Expression, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan 61-614, Poland
| | - Dariusz J Smolinski
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Torun 87-100, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Torun 87-100, Poland
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Abstract
The positive-sense flavivirus RNA genome bears a cap 1 structure essential for RNA stability and viral protein translation, and the formation of cap 1 requires the virally encoded nonstructural protein NS5 harboring guanylyltransferase (GTase), cap guanine N7 methyltransferase (N7 MTase), and 5'-nucleotide ribose 2'-O MTase activities in its single-domain MTase module. Despite numerous MTase-containing structures reported, the structural evidence for a critical GMP-enzyme intermediate formation and RNA repositioning when transitioning among different reactions is missing. Here, we report 10 high-resolution MTase crystal structures of Omsk hemorrhagic fever virus (OHFV), a representative high-consequence tick-borne flavivirus, capturing previously unidentified GMP-arginine adduct structures and a rarely observed capped RNA conformation. These structures help us thread capping events in the canonical model with a structure-based hypothesis involving the flipping of the 5' nucleotide, while the observation of an m7GMP-arginine adduct is compatible with an alternate capping model that decouples the N7 and 2'-O methylation steps. IMPORTANCE The methyltransferase (MTase) domain of flavivirus NS5 is unique in harboring guanylyltransferase (GTase), N7 MTase, and 2'-O MTase activities, playing a central role in viral RNA capping. However, the detailed mechanisms of the multistep capping process remain elusive. Here, we report 10 crystal structures of a flavivirus MTase to help understand the guanylyl transfer from GTP to the GTase itself and the transition between guanylyl transfer and methylation steps. In particular, a previously unobserved GMP-arginine covalent intermediate was captured multiple times in MTase crystal soaking trials with GTP present in the soaking solution, supporting its role in bridging the guanylyl transfer from GTP to the GTase and subsequent transfer to the 5'-diphosphate RNA.
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7
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Appel LM, Franke V, Bruno M, Grishkovskaya I, Kasiliauskaite A, Kaufmann T, Schoeberl UE, Puchinger MG, Kostrhon S, Ebenwaldner C, Sebesta M, Beltzung E, Mechtler K, Lin G, Vlasova A, Leeb M, Pavri R, Stark A, Akalin A, Stefl R, Bernecky C, Djinovic-Carugo K, Slade D. PHF3 regulates neuronal gene expression through the Pol II CTD reader domain SPOC. Nat Commun 2021; 12:6078. [PMID: 34667177 PMCID: PMC8526623 DOI: 10.1038/s41467-021-26360-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 09/29/2021] [Indexed: 12/16/2022] Open
Abstract
The C-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II) is a regulatory hub for transcription and RNA processing. Here, we identify PHD-finger protein 3 (PHF3) as a regulator of transcription and mRNA stability that docks onto Pol II CTD through its SPOC domain. We characterize SPOC as a CTD reader domain that preferentially binds two phosphorylated Serine-2 marks in adjacent CTD repeats. PHF3 drives liquid-liquid phase separation of phosphorylated Pol II, colocalizes with Pol II clusters and tracks with Pol II across the length of genes. PHF3 knock-out or SPOC deletion in human cells results in increased Pol II stalling, reduced elongation rate and an increase in mRNA stability, with marked derepression of neuronal genes. Key neuronal genes are aberrantly expressed in Phf3 knock-out mouse embryonic stem cells, resulting in impaired neuronal differentiation. Our data suggest that PHF3 acts as a prominent effector of neuronal gene regulation by bridging transcription with mRNA decay.
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Affiliation(s)
- Lisa-Marie Appel
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Vedran Franke
- The Berlin Institute for Medical Systems Biology, Max Delbrück Center, Berlin, Germany
| | - Melania Bruno
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Irina Grishkovskaya
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Aiste Kasiliauskaite
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Tanja Kaufmann
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Ursula E Schoeberl
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Martin G Puchinger
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Sebastian Kostrhon
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Carmen Ebenwaldner
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Marek Sebesta
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Etienne Beltzung
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Campus-Vienna-Biocenter 1, Vienna Biocenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Vienna, Austria
| | - Gen Lin
- Research Institute of Molecular Pathology (IMP), Campus-Vienna-Biocenter 1, Vienna Biocenter (VBC), Vienna, Austria
| | - Anna Vlasova
- Research Institute of Molecular Pathology (IMP), Campus-Vienna-Biocenter 1, Vienna Biocenter (VBC), Vienna, Austria
| | - Martin Leeb
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Campus-Vienna-Biocenter 1, Vienna Biocenter (VBC), Vienna, Austria
| | - Alexander Stark
- Research Institute of Molecular Pathology (IMP), Campus-Vienna-Biocenter 1, Vienna Biocenter (VBC), Vienna, Austria
| | - Altuna Akalin
- The Berlin Institute for Medical Systems Biology, Max Delbrück Center, Berlin, Germany
| | - Richard Stefl
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Carrie Bernecky
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, Klosterneuburg, Austria
| | - Kristina Djinovic-Carugo
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
- Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Dea Slade
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria.
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria.
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria.
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8
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Dwivedy A, Mariadasse R, Ahmad M, Chakraborty S, Kar D, Tiwari S, Bhattacharyya S, Sonar S, Mani S, Tailor P, Majumdar T, Jeyakanthan J, Biswal BK. Characterization of the NiRAN domain from RNA-dependent RNA polymerase provides insights into a potential therapeutic target against SARS-CoV-2. PLoS Comput Biol 2021; 17:e1009384. [PMID: 34516563 PMCID: PMC8478224 DOI: 10.1371/journal.pcbi.1009384] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 09/28/2021] [Accepted: 08/26/2021] [Indexed: 12/14/2022] Open
Abstract
Apart from the canonical fingers, palm and thumb domains, the RNA dependent RNA polymerases (RdRp) from the viral order Nidovirales possess two additional domains. Of these, the function of the Nidovirus RdRp associated nucleotidyl transferase domain (NiRAN) remains unanswered. The elucidation of the 3D structure of RdRp from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), provided the first ever insights into the domain organisation and possible functional characteristics of the NiRAN domain. Using in silico tools, we predict that the NiRAN domain assumes a kinase or phosphotransferase like fold and binds nucleoside triphosphates at its proposed active site. Additionally, using molecular docking we have predicted the binding of three widely used kinase inhibitors and five well characterized anti-microbial compounds at the NiRAN domain active site along with their drug-likeliness. For the first time ever, using basic biochemical tools, this study shows the presence of a kinase like activity exhibited by the SARS-CoV-2 RdRp. Interestingly, a well-known kinase inhibitor- Sorafenib showed a significant inhibition and dampened viral load in SARS-CoV-2 infected cells. In line with the current global COVID-19 pandemic urgency and the emergence of newer strains with significantly higher infectivity, this study provides a new anti-SARS-CoV-2 drug target and potential lead compounds for drug repurposing against SARS-CoV-2. The on-going coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is significantly affecting the world health. Unfortunately, over 180 million cases of COVID-19 resulting in nearly 4 million deaths have been reported till June, 2021. In this study, using a combination of bioinformatics, biochemical and mass spectrometry methods, we show that the Nidovirus RdRp associated Nucleotidyl transferase (NiRAN) domain of the RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 exhibits a kinase like activity. Additionally, we also show that few broad spectrum anti-cancer and anti-microbial drugs dampen this kinase like activity. Of note, Sorafenib, an FDA approved anti-cancer kinase inhibiting drug significantly reduces the SARS-CoV-2 load in cell lines. Our study suggests that NiRAN domain of the SARS-CoV-2 RdRp is indispensible for the successful viral life cycle and shows that abolishing this enzymatic function of RdRp by small molecule inhibitors may open novel avenues for COVID-19 therapeutics.
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Affiliation(s)
| | | | | | | | | | | | | | - Sudipta Sonar
- Translational Health Science and Technology Institute, Faridabad, India
| | - Shailendra Mani
- Translational Health Science and Technology Institute, Faridabad, India
| | | | - Tanmay Majumdar
- National Institute of Immunology, New Delhi, India
- * E-mail: (TM); (JJ); (BKB)
| | - Jeyaraman Jeyakanthan
- Department of Bioinformatics, Alagappa University, Tamil Nadu, India
- * E-mail: (TM); (JJ); (BKB)
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9
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Dwivedy A, Mariadasse R, Ahmad M, Chakraborty S, Kar D, Tiwari S, Bhattacharyya S, Sonar S, Mani S, Tailor P, Majumdar T, Jeyakanthan J, Biswal BK. Characterization of the NiRAN domain from RNA-dependent RNA polymerase provides insights into a potential therapeutic target against SARS-CoV-2. PLoS Comput Biol 2021. [DOI: https://doi.org/10.1371/journal.pcbi.1009384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apart from the canonical fingers, palm and thumb domains, the RNA dependent RNA polymerases (RdRp) from the viral order Nidovirales possess two additional domains. Of these, the function of the Nidovirus RdRp associated nucleotidyl transferase domain (NiRAN) remains unanswered. The elucidation of the 3D structure of RdRp from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), provided the first ever insights into the domain organisation and possible functional characteristics of the NiRAN domain. Using in silico tools, we predict that the NiRAN domain assumes a kinase or phosphotransferase like fold and binds nucleoside triphosphates at its proposed active site. Additionally, using molecular docking we have predicted the binding of three widely used kinase inhibitors and five well characterized anti-microbial compounds at the NiRAN domain active site along with their drug-likeliness. For the first time ever, using basic biochemical tools, this study shows the presence of a kinase like activity exhibited by the SARS-CoV-2 RdRp. Interestingly, a well-known kinase inhibitor- Sorafenib showed a significant inhibition and dampened viral load in SARS-CoV-2 infected cells. In line with the current global COVID-19 pandemic urgency and the emergence of newer strains with significantly higher infectivity, this study provides a new anti-SARS-CoV-2 drug target and potential lead compounds for drug repurposing against SARS-CoV-2.
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10
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Transcription and chromatin-based surveillance mechanism controls suppression of cryptic antisense transcription. Cell Rep 2021; 36:109671. [PMID: 34496258 PMCID: PMC8441049 DOI: 10.1016/j.celrep.2021.109671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 08/26/2020] [Accepted: 08/13/2021] [Indexed: 12/25/2022] Open
Abstract
Phosphorylation of the RNA polymerase II C-terminal domain Y1S2P3T4S5P6S7 consensus sequence coordinates key events during transcription, and its deregulation leads to defects in transcription and RNA processing. Here, we report that the histone deacetylase activity of the fission yeast Hos2/Set3 complex plays an important role in suppressing cryptic initiation of antisense transcription when RNA polymerase II phosphorylation is dysregulated due to the loss of Ssu72 phosphatase. Interestingly, although single Hos2 and Set3 mutants have little effect, loss of Hos2 or Set3 combined with ssu72Δ results in a synergistic increase in antisense transcription globally and correlates with elevated sensitivity to genotoxic agents. We demonstrate a key role for the Ssu72/Hos2/Set3 mechanism in the suppression of cryptic antisense transcription at the 3' end of convergent genes that are most susceptible to these defects, ensuring the fidelity of gene expression within dense genomes of simple eukaryotes.
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11
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Mompeán M, Oroz J, Laurents DV. Do polyproline II helix associations modulate biomolecular condensates? FEBS Open Bio 2021; 11:2390-2399. [PMID: 33934561 PMCID: PMC8409303 DOI: 10.1002/2211-5463.13163] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 03/29/2021] [Accepted: 04/09/2021] [Indexed: 12/22/2022] Open
Abstract
Biomolecular condensates are microdroplets that form inside cells and serve to selectively concentrate proteins, RNAs and other molecules for a variety of physiological functions, but can contribute to cancer, neurodegenerative diseases and viral infections. The formation of these condensates is driven by weak, transient interactions between molecules. These weak associations can operate at the level of whole protein domains, elements of secondary structure or even moieties composed of just a few atoms. Different types of condensates do not generally combine to form larger microdroplets, suggesting that each uses a distinct class of attractive interactions. Here, we address whether polyproline II (PPII) helices mediate condensate formation. By combining with PPII-binding elements such as GYF, WW, profilin, SH3 or OCRE domains, PPII helices help form lipid rafts, nuclear speckles, P-body-like neuronal granules, enhancer complexes and other condensates. The number of PPII helical tracts or tandem PPII-binding domains can strongly influence condensate stability. Many PPII helices have a low content of proline residues, which hinders their identification. Recently, we characterized the NMR spectral properties of a Gly-rich, Pro-poor protein composed of six PPII helices. Based on those results, we predicted that many Gly-rich segments may form PPII helices and interact with PPII-binding domains. This prediction is being tested and could join the palette of verified interactions contributing to biomolecular condensate formation.
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Affiliation(s)
- Miguel Mompeán
- Departamento de Química Física BiológicaInstituto de Química Física RocasolanoCSICMadridEspaña
| | - Javier Oroz
- Departamento de Química Física BiológicaInstituto de Química Física RocasolanoCSICMadridEspaña
| | - Douglas V. Laurents
- Departamento de Química Física BiológicaInstituto de Química Física RocasolanoCSICMadridEspaña
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12
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Kasprzyk R, Jemielity J. Enzymatic Assays to Explore Viral mRNA Capping Machinery. Chembiochem 2021; 22:3236-3253. [PMID: 34291555 PMCID: PMC8426721 DOI: 10.1002/cbic.202100291] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/21/2021] [Indexed: 12/25/2022]
Abstract
In eukaryotes, mRNA is modified by the addition of the 7-methylguanosine (m7 G) 5' cap to protect mRNA from premature degradation, thereby enhancing translation and enabling differentiation between self (endogenous) and non-self RNAs (e. g., viral ones). Viruses often develop their own mRNA capping pathways to augment the expression of their proteins and escape host innate immune response. Insights into this capping system may provide new ideas for therapeutic interventions and facilitate drug discovery, e. g., against viruses that cause pandemic outbreaks, such as beta-coronaviruses SARS-CoV (2002), MARS-CoV (2012), and the most recent SARS-CoV-2. Thus, proper methods for the screening of large compound libraries are required to identify lead structures that could serve as a basis for rational antiviral drug design. This review summarizes the methods that allow the monitoring of the activity and inhibition of enzymes involved in mRNA capping.
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Affiliation(s)
- Renata Kasprzyk
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland.,College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Jacek Jemielity
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
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13
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Dieci G. Removing quote marks from the RNA polymerase II CTD 'code'. Biosystems 2021; 207:104468. [PMID: 34216714 DOI: 10.1016/j.biosystems.2021.104468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 11/27/2022]
Abstract
In eukaryotes, RNA polymerase II (Pol II) is responsible for the synthesis of all mRNAs and myriads of short and long untranslated RNAs, whose fabrication involves close spatiotemporal coordination between transcription, RNA processing and chromatin modification. Crucial for such a coordination is an unusual C-terminal domain (CTD) of the Pol II largest subunit, made of tandem repetitions (26 in yeast, 52 in chordates) of the heptapeptide with the consensus sequence YSPTSPS. Although largely unstructured and with poor sequence content, the Pol II CTD derives its extraordinary functional versatility from the fact that each amino acid in the heptapeptide can be posttranslationally modified, and that different combinations of CTD covalent marks are specifically recognized by different protein binding partners. These features have led to propose the existence of a Pol II CTD code, but this expression is generally used by authors with some caution, revealed by the frequent use of quote marks for the word 'code'. Based on the theoretical framework of code biology, it is argued here that the Pol II CTD modification system meets the requirements of a true organic code, where different CTD modification states represent organic signs whose organic meanings are biological reactions contributing to the many facets of RNA biogenesis in coordination with RNA synthesis by Pol II. Importantly, the Pol II CTD code is instantiated by adaptor proteins possessing at least two distinct domains, one of which devoted to specific recognition of CTD modification profiles. Furthermore, code rules can be altered by experimental interchange of CTD recognition domains of different adaptor proteins, a fact arguing in favor of the arbitrariness, and thus bona fide character, of the Pol II CTD code. Since the growing family of CTD adaptors includes RNA binding proteins and histone modification complexes, the Pol II CTD code is by its nature integrated with other organic codes, in particular the splicing code and the histone code. These issues will be discussed taking into account fascinating developments in Pol II CTD research, like the discovery of novel modifications at non-consensus sites, the recently recognized CTD physicochemical properties favoring liquid-liquid phase separation, and the discovery that the Pol II CTD, originated before the divergence of most extant eukaryotic taxa, has expanded and diversified with developmental complexity in animals and plants.
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Affiliation(s)
- Giorgio Dieci
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 23/A, 43124, Parma, Italy.
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14
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CDK9 keeps RNA polymerase II on track. Cell Mol Life Sci 2021; 78:5543-5567. [PMID: 34146121 PMCID: PMC8257543 DOI: 10.1007/s00018-021-03878-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/26/2021] [Accepted: 06/08/2021] [Indexed: 12/30/2022]
Abstract
Cyclin-dependent kinase 9 (CDK9), the kinase component of positive transcription elongation factor b (P-TEFb), is essential for transcription of most protein-coding genes by RNA polymerase II (RNAPII). By releasing promoter-proximally paused RNAPII into gene bodies, CDK9 controls the entry of RNAPII into productive elongation and is, therefore, critical for efficient synthesis of full-length messenger (m)RNAs. In recent years, new players involved in P-TEFb-dependent processes have been identified and an important function of CDK9 in coordinating elongation with transcription initiation and termination has been unveiled. As the regulatory functions of CDK9 in gene expression continue to expand, a number of human pathologies, including cancers, have been associated with aberrant CDK9 activity, underscoring the need to properly regulate CDK9. Here, I provide an overview of CDK9 function and regulation, with an emphasis on CDK9 dysregulation in human diseases.
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15
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Bage MG, Almohammed R, Cowling VH, Pisliakov A. A novel RNA pol II CTD interaction site on the mRNA capping enzyme is essential for its allosteric activation. Nucleic Acids Res 2021; 49:3109-3126. [PMID: 33684220 PMCID: PMC8034621 DOI: 10.1093/nar/gkab130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/09/2021] [Accepted: 02/16/2021] [Indexed: 11/12/2022] Open
Abstract
Recruitment of the mRNA capping enzyme (CE/RNGTT) to the site of transcription is essential for the formation of the 5' mRNA cap, which in turn ensures efficient transcription, splicing, polyadenylation, nuclear export and translation of mRNA in eukaryotic cells. The CE GTase is recruited and activated by the Serine-5 phosphorylated carboxyl-terminal domain (CTD) of RNA polymerase II. Through the use of molecular dynamics simulations and enhanced sampling techniques, we provide a systematic and detailed characterization of the human CE-CTD interface, describing the effect of the CTD phosphorylation state, length and orientation on this interaction. Our computational analyses identify novel CTD interaction sites on the human CE GTase surface and quantify their relative contributions to CTD binding. We also identify, for the first time, allosteric connections between the CE GTase active site and the CTD binding sites, allowing us to propose a mechanism for allosteric activation. Through binding and activity assays we validate the novel CTD binding sites and show that the CDS2 site is essential for CE GTase activity stimulation. Comparison of the novel sites with cocrystal structures of the CE-CTD complex in different eukaryotic taxa reveals that this interface is considerably more conserved than previous structures have indicated.
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Affiliation(s)
- Marcus G Bage
- Computational Biology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Rajaei Almohammed
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Victoria H Cowling
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Andrei V Pisliakov
- Computational Biology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- Physics, School of Science and Engineering, University of Dundee, Dundee DD1 4HN, UK
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16
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Krischuns T, Lukarska M, Naffakh N, Cusack S. Influenza Virus RNA-Dependent RNA Polymerase and the Host Transcriptional Apparatus. Annu Rev Biochem 2021; 90:321-348. [PMID: 33770447 DOI: 10.1146/annurev-biochem-072820-100645] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Influenza virus RNA-dependent RNA polymerase (FluPol) transcribes the viral RNA genome in the infected cell nucleus. In the 1970s, researchers showed that viral transcription depends on host RNA polymerase II (RNAP II) activity and subsequently that FluPol snatches capped oligomers from nascent RNAP II transcripts to prime its own transcription. Exactly how this occurs remains elusive. Here, we review recent advances in the mechanistic understanding of FluPol transcription and early events in RNAP II transcription that are relevant to cap-snatching. We describe the known direct interactions between FluPol and the RNAP II C-terminal domain and summarize the transcription-related host factors that have been found to interact with FluPol. We also discuss open questions regarding how FluPol may be targeted to actively transcribing RNAP II and the exact context and timing of cap-snatching, which is presumed to occur after cap completion but before the cap is sequestered by the nuclear cap-binding complex.
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Affiliation(s)
- Tim Krischuns
- Unité Biologie des ARN et Virus Influenza, Département de Virologie, Institut Pasteur, CNRS UMR 3569, F-75015 Paris, France; ,
| | - Maria Lukarska
- European Molecular Biology Laboratory, 38042 Grenoble CEDEX 9, France; .,Current affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA;
| | - Nadia Naffakh
- Unité Biologie des ARN et Virus Influenza, Département de Virologie, Institut Pasteur, CNRS UMR 3569, F-75015 Paris, France; ,
| | - Stephen Cusack
- European Molecular Biology Laboratory, 38042 Grenoble CEDEX 9, France;
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17
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Namitz KEW, Zheng T, Canning AJ, Alicea-Velazquez NL, Castañeda CA, Cosgrove MS, Hanes SD. Structure analysis suggests Ess1 isomerizes the carboxy-terminal domain of RNA polymerase II via a bivalent anchoring mechanism. Commun Biol 2021; 4:398. [PMID: 33767358 PMCID: PMC7994582 DOI: 10.1038/s42003-021-01906-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/24/2021] [Indexed: 01/07/2023] Open
Abstract
Accurate gene transcription in eukaryotes depends on isomerization of serine-proline bonds within the carboxy-terminal domain (CTD) of RNA polymerase II. Isomerization is part of the "CTD code" that regulates recruitment of proteins required for transcription and co-transcriptional RNA processing. Saccharomyces cerevisiae Ess1 and its human ortholog, Pin1, are prolyl isomerases that engage the long heptad repeat (YSPTSPS)26 of the CTD by an unknown mechanism. Here, we used an integrative structural approach to decipher Ess1 interactions with the CTD. Ess1 has a rigid linker between its WW and catalytic domains that enforces a distance constraint for bivalent interaction with the ends of long CTD substrates (≥4-5 heptad repeats). Our binding results suggest that the Ess1 WW domain anchors the proximal end of the CTD substrate during isomerization, and that linker divergence may underlie evolution of substrate specificity.
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Affiliation(s)
- Kevin E. W. Namitz
- grid.411023.50000 0000 9159 4457Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY USA ,grid.29857.310000 0001 2097 4281Present Address: Department of Chemistry, Pennsylvania State University, University Park, PA USA
| | - Tongyin Zheng
- grid.264484.80000 0001 2189 1568Departments of Biology and Chemistry, Syracuse University, Syracuse, NY USA
| | - Ashley J. Canning
- grid.411023.50000 0000 9159 4457Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY USA
| | - Nilda L. Alicea-Velazquez
- grid.411023.50000 0000 9159 4457Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY USA ,grid.247980.00000 0001 2184 3689Present Address: Department of Chemistry and Biochemistry, Central Connecticut State University, New Britain, CT USA
| | - Carlos A. Castañeda
- grid.264484.80000 0001 2189 1568Departments of Biology and Chemistry, Syracuse University, Syracuse, NY USA
| | - Michael S. Cosgrove
- grid.411023.50000 0000 9159 4457Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY USA
| | - Steven D. Hanes
- grid.411023.50000 0000 9159 4457Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY USA
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18
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Interplay of mRNA capping and transcription machineries. Biosci Rep 2021; 40:221784. [PMID: 31904821 PMCID: PMC6981093 DOI: 10.1042/bsr20192825] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 12/31/2022] Open
Abstract
Early stages of transcription from eukaryotic promoters include two principal events: the capping of newly synthesized mRNA and the transition of RNA polymerase II from the preinitiation complex to the productive elongation state. The capping checkpoint model implies that these events are tightly coupled, which is necessary for ensuring the proper capping of newly synthesized mRNA. Recent findings also show that the capping machinery has a wider effect on transcription and the entire gene expression process. The molecular basis of these phenomena is discussed.
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19
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Chia M, Li C, Marques S, Pelechano V, Luscombe NM, van Werven FJ. High-resolution analysis of cell-state transitions in yeast suggests widespread transcriptional tuning by alternative starts. Genome Biol 2021; 22:34. [PMID: 33446241 PMCID: PMC7807719 DOI: 10.1186/s13059-020-02245-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 12/15/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The start and end sites of messenger RNAs (TSSs and TESs) are highly regulated, often in a cell-type-specific manner. Yet the contribution of transcript diversity in regulating gene expression remains largely elusive. We perform an integrative analysis of multiple highly synchronized cell-fate transitions and quantitative genomic techniques in Saccharomyces cerevisiae to identify regulatory functions associated with transcribing alternative isoforms. RESULTS Cell-fate transitions feature widespread elevated expression of alternative TSS and, to a lesser degree, TES usage. These dynamically regulated alternative TSSs are located mostly upstream of canonical TSSs, but also within gene bodies possibly encoding for protein isoforms. Increased upstream alternative TSS usage is linked to various effects on canonical TSS levels, which range from co-activation to repression. We identified two key features linked to these outcomes: an interplay between alternative and canonical promoter strengths, and distance between alternative and canonical TSSs. These two regulatory properties give a plausible explanation of how locally transcribed alternative TSSs control gene transcription. Additionally, we find that specific chromatin modifiers Set2, Set3, and FACT play an important role in mediating gene repression via alternative TSSs, further supporting that the act of upstream transcription drives the local changes in gene transcription. CONCLUSIONS The integrative analysis of multiple cell-fate transitions suggests the presence of a regulatory control system of alternative TSSs that is important for dynamic tuning of gene expression. Our work provides a framework for understanding how TSS heterogeneity governs eukaryotic gene expression, particularly during cell-fate changes.
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Affiliation(s)
- Minghao Chia
- The Francis Crick Institute, London, UK
- Genome Institute of Singapore, 60 Biopolis Street, Genome, #02-01, Singapore, 138672, Singapore
| | - Cai Li
- The Francis Crick Institute, London, UK
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Sueli Marques
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Vicente Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Nicholas M Luscombe
- The Francis Crick Institute, London, UK
- Okinawa Institute of Science & Technology Graduate University, Okinawa, 904-0495, Japan
- UCL Genetics Institute, University College London, London, WC1E 6BT, UK
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20
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Yeast Spt6 Reads Multiple Phosphorylation Patterns of RNA Polymerase II C-Terminal Domain In Vitro. J Mol Biol 2020; 432:4092-4107. [PMID: 32439331 PMCID: PMC7327521 DOI: 10.1016/j.jmb.2020.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/21/2022]
Abstract
Transcription elongation factor Spt6 associates with RNA polymerase II (RNAP II) via a tandem SH2 (tSH2) domain. The mechanism and significance of the RNAP II–Spt6 interaction is still unclear. Recently, it was proposed that Spt6-tSH2 is recruited via a newly described phosphorylated linker between the Rpb1 core and its C-terminal domain (CTD). Here, we report binding studies with isolated tSH2 of Spt6 (Spt6-tSH2) and Spt6 lacking the first unstructured 297 residues (Spt6ΔN) with a minimal CTD substrate of two repetitive heptads phosphorylated at different sites. The data demonstrate that Spt6 also binds the phosphorylated CTD, a site that was originally proposed as a recognition epitope. We also show that an extended CTD substrate harboring 13 repetitive heptads of the tyrosine-phosphorylated CTD binds Spt6-tSH2 and Spt6ΔN with tighter affinity than the minimal CTD substrate. The enhanced binding is achieved by avidity originating from multiple phosphorylation marks present in the CTD. Interestingly, we found that the steric effects of additional domains in the Spt6ΔN construct partially obscure the binding of the tSH2 domain to the multivalent ligand. We show that Spt6-tSH2 binds various phosphorylation patterns in the CTD and found that the studied combinations of phospho-CTD marks (1,2; 1,5; 2,4; and 2,7) all facilitate the interaction of CTD with Spt6. Our structural studies reveal a plasticity of the tSH2 binding pockets that enables the accommodation of CTDs with phosphorylation marks in different registers. High-affinity Pol II CTD-binding by Spt6 is achieved by avidity originating from multiple phosphorylation marks presented in the CTD, suggesting how phosphorylation levels fine-tune the CTD interactome. Structure of RNAP II CTD bound with tandem SH2 domain of Spt6 reveals how phosphorylated CTD is recognized. Isolated tSH2 of Spt6 binds the extended CTD substrate with tighter affinity than nearly full-length Spt6, suggesting that the steric effects of additional domains in Spt6 influence the binding of the tSH2 domain to the multivalent CTD ligand.
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21
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Lyons DE, McMahon S, Ott M. A combinatorial view of old and new RNA polymerase II modifications. Transcription 2020; 11:66-82. [PMID: 32401151 DOI: 10.1080/21541264.2020.1762468] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The production of mRNA is a dynamic process that is highly regulated by reversible post-translational modifications of the C-terminal domain (CTD) of RNA polymerase II. The CTD is a highly repetitive domain consisting mostly of the consensus heptad sequence Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7. Phosphorylation of serine residues within this repeat sequence is well studied, but modifications of all residues have been described. Here, we focus on integrating newly identified and lesser-studied CTD post-translational modifications into the existing framework. We also review the growing body of work demonstrating crosstalk between different CTD modifications and the functional consequences of such crosstalk on the dynamics of transcriptional regulation.
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Affiliation(s)
- Danielle E Lyons
- Gladstone Institute of Virology and Immunology, San Francisco, CA, USA
| | - Sarah McMahon
- Gladstone Institute of Virology and Immunology, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco , San Francisco, CA, USA
| | - Melanie Ott
- Gladstone Institute of Virology and Immunology, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco , San Francisco, CA, USA
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22
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Hu X, Chen LF. Pinning Down the Transcription: A Role for Peptidyl-Prolyl cis-trans Isomerase Pin1 in Gene Expression. Front Cell Dev Biol 2020; 8:179. [PMID: 32266261 PMCID: PMC7100383 DOI: 10.3389/fcell.2020.00179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/04/2020] [Indexed: 12/14/2022] Open
Abstract
Pin1 is a peptidyl-prolyl cis-trans isomerase that specifically binds to a phosphorylated serine or threonine residue preceding a proline (pSer/Thr-Pro) motif and catalyzes the cis-trans isomerization of proline imidic peptide bond, resulting in conformational change of its substrates. Pin1 regulates many biological processes and is also involved in the development of human diseases, like cancer and neurological diseases. Many Pin1 substrates are transcription factors and transcription regulators, including RNA polymerase II (RNAPII) and factors associated with transcription initiation, elongation, termination and post-transcription mRNA decay. By changing the stability, subcellular localization, protein-protein or protein-DNA/RNA interactions of these transcription related proteins, Pin1 modulates the transcription of many genes related to cell proliferation, differentiation, apoptosis and immune response. Here, we will discuss how Pin regulates the properties of these transcription relevant factors for effective gene expression and how Pin1-mediated transcription contributes to the diverse pathophysiological functions of Pin1.
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Affiliation(s)
- Xiangming Hu
- Fujian Key Laboratory for Translational Research in Cancer and Neurodegenerative Diseases, Institute for Translational Medicine, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Lin-Feng Chen
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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23
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Grimm C, Hillen HS, Bedenk K, Bartuli J, Neyer S, Zhang Q, Hüttenhofer A, Erlacher M, Dienemann C, Schlosser A, Urlaub H, Böttcher B, Szalay AA, Cramer P, Fischer U. Structural Basis of Poxvirus Transcription: Vaccinia RNA Polymerase Complexes. Cell 2019; 179:1537-1550.e19. [DOI: 10.1016/j.cell.2019.11.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 08/20/2019] [Accepted: 11/14/2019] [Indexed: 01/06/2023]
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24
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Abstract
In this review, Core et al. discuss the recent advances in our understanding of the early steps in Pol II transcription, highlighting the events and factors involved in the establishment and release of paused Pol II. They also discuss a number of unanswered questions about the regulation and function of Pol II pausing. Precise spatio–temporal control of gene activity is essential for organismal development, growth, and survival in a changing environment. Decisive steps in gene regulation involve the pausing of RNA polymerase II (Pol II) in early elongation, and the controlled release of paused polymerase into productive RNA synthesis. Here we describe the factors that enable pausing and the events that trigger Pol II release into the gene. We also discuss open questions in the field concerning the stability of paused Pol II, nucleosomes as obstacles to elongation, and potential roles of pausing in defining the precision and dynamics of gene expression.
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Affiliation(s)
- Leighton Core
- Department of Molecular and Cell Biology, Institute of Systems Genomics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Karen Adelman
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
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25
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Efficient and robust preparation of tyrosine phosphorylated intrinsically disordered proteins. Biotechniques 2019; 67:16-22. [PMID: 31092000 DOI: 10.2144/btn-2019-0033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are subject to post-translational modifications. This allows the same polypeptide to be involved in different interaction networks with different consequences, ranging from regulatory signalling networks to the formation of membrane-less organelles. We report a robust method for co-expression of modification enzyme and SUMO-tagged IDPs with a subsequent purification procedure that allows for the production of modified IDP. The robustness of our protocol is demonstrated using a challenging system: RNA polymerase II C-terminal domain (CTD); that is, a low-complexity repetitive region with multiple phosphorylation sites. In vitro phosphorylation approaches fail to yield multiple-site phosphorylated CTD, whereas our in vivo protocol allows the rapid production of near homogeneous phosphorylated CTD at a low cost. These samples can be used in functional and structural studies.
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26
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Carrocci TJ, Neugebauer KM. Pre-mRNA Splicing in the Nuclear Landscape. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2019; 84:11-20. [PMID: 32493763 PMCID: PMC7384967 DOI: 10.1101/sqb.2019.84.040402] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Eukaryotic gene expression requires the cumulative activity of multiple molecular machines to synthesize and process newly transcribed pre-messenger RNA. Introns, the noncoding regions in pre-mRNA, must be removed by the spliceosome, which assembles on the pre-mRNA as it is transcribed by RNA polymerase II (Pol II). The assembly and activity of the spliceosome can be modulated by features including the speed of transcription elongation, chromatin, post-translational modifications of Pol II and histone tails, and other RNA processing events like 5'-end capping. Here, we review recent work that has revealed cooperation and coordination among co-transcriptional processing events and speculate on new avenues of research. We anticipate new mechanistic insights capable of unraveling the relative contribution of coupled processing to gene expression.
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Affiliation(s)
- Tucker J Carrocci
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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27
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Babokhov M, Mosaheb MM, Baker RW, Fuchs SM. Repeat-Specific Functions for the C-Terminal Domain of RNA Polymerase II in Budding Yeast. G3 (BETHESDA, MD.) 2018; 8:1593-1601. [PMID: 29523636 PMCID: PMC5940151 DOI: 10.1534/g3.118.200086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 03/06/2018] [Indexed: 12/22/2022]
Abstract
The C-terminal domain (CTD) of the largest subunit of RNA polymerase II (RNAPII) is required to regulate transcription and to integrate it with other essential cellular processes. In the budding yeast Saccharomyces cerevisiae, the CTD of Rpb1p consists of 26 conserved heptad repeats that are post-translationally modified to orchestrate protein factor binding at different stages of the transcription cycle. A long-standing question in the study of the CTD is if there are any functional differences between the 26 repeats. In this study, we present evidence that repeats of identical sequence have different functions based on their position within the CTD. We assembled plasmids expressing Rpb1p with serine to alanine substitutions in three defined regions of the CTD and measured a range of phenotypes for yeast expressing these constructs. Mutations in the beginning and middle regions of the CTD had drastic, and region-specific effects, while mutating the distal region had no observable phenotype. Further mutational analysis determined that Ser5 within the first region of repeats was solely responsible for the observed growth differences and sequencing fast-growing suppressors allowed us to further define the functional regions of the CTD. This mutational analysis is consistent with current structural models for how the RNAPII holoenzyme and the CTD specifically would reside in complex with Mediator and establishes a foundation for studying regioselective binding along the repetitive RNAPII CTD.
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Affiliation(s)
| | | | - Richard W Baker
- Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92093
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Cdk-related kinase 9 regulates RNA polymerase II mediated transcription in Toxoplasma gondii. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:572-585. [PMID: 29466697 DOI: 10.1016/j.bbagrm.2018.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/31/2018] [Accepted: 02/13/2018] [Indexed: 11/20/2022]
Abstract
Cyclin-dependent kinases are an essential part of eukaryotic transcriptional machinery. In Apicomplexan parasites, the role and relevance of the kinases in the multistep process of transcription seeks more attention given the absence of full repertoire of canonical Cdks and cognate cyclin partners. In this study, we functionally characterize T. gondii Cdk-related kinase 9 (TgCrk9) showing maximal homology to eukaryotic Cdk9. An uncanonical cyclin, TgCyclin L, colocalizes with TgCrk9 in the parasite nucleus and co-immunoprecipitate, could activate the kinase in-vitro. We identify two threonines in conserved T-loop domain of TgCrk9 that are important for its activity. The activated TgCrk9 phosphorylates C-terminal domain (CTD) of TgRpb1, the largest subunit of RNA polymerase II highlighting its role in transcription. Selective chemical inhibition of TgCrk9 affected serine 2 phosphorylation in the heptapeptide repeats of TgRpb1-CTD towards 3' end of genes consistent with a possible role in transcription elongation. Interestingly, TgCrk9 kinase activity is regulated by the upstream TgCrk7 based CAK complex. TgCrk9 was found to functionally complement the role of its yeast counterpart Bur1 establishing its role as an important transcriptional kinase. In this study, we provide robust evidence that TgCrk9 is an important part of transcription machinery regulating gene expression in T. gondii.
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Mullen NJ, Price DH. Hydrogen peroxide yields mechanistic insights into human mRNA capping enzyme function. PLoS One 2017; 12:e0186423. [PMID: 29028835 PMCID: PMC5640233 DOI: 10.1371/journal.pone.0186423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/29/2017] [Indexed: 12/16/2022] Open
Abstract
Capping of nascent RNA polymerase II (Pol II) transcripts is required for gene expression and the first two steps are catalyzed by separate 5' triphosphatase and guanylyltransferase activities of the human capping enzyme (HCE). The cap is added co-transcriptionally, but how the two activities are coordinated is unclear. Our previous in vitro work has suggested that an unidentified factor modulates the minimum length at which nascent transcripts can be capped. Using the same well-established in vitro system with hydrogen peroxide as a capping inhibitor, we show that this unidentified factor targets the guanylyltransferase activity of HCE. We also uncover the mechanism of HCE inhibition by hydrogen peroxide, and by using mass spectrometry demonstrate that the active site cysteine residue of the HCE triphosphatase domain becomes oxidized. Using recombinant proteins for the two separated HCE domains, we provide evidence that the triphosphatase normally acts on transcripts shorter than can be acted upon by the guanylyltransferase. Our further characterization of the capping reaction dependence on transcript length and its interaction with the unidentified modulator of capping raises the interesting possibility that the capping reaction could be regulated.
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Affiliation(s)
- Nicholas J. Mullen
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - David H. Price
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Pauwels K, Lebrun P, Tompa P. To be disordered or not to be disordered: is that still a question for proteins in the cell? Cell Mol Life Sci 2017; 74:3185-3204. [PMID: 28612216 PMCID: PMC11107661 DOI: 10.1007/s00018-017-2561-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/01/2017] [Indexed: 12/26/2022]
Abstract
There is ample evidence that many proteins or regions of proteins lack a well-defined folded structure under native-like conditions. These are called intrinsically disordered proteins (IDPs) or intrinsically disordered regions (IDRs). Whether this intrinsic disorder is also their main structural characteristic in living cells has been a matter of intense debate. The structural analysis of IDPs became an important challenge also because of their involvement in a plethora of human diseases, which made IDPs attractive targets for therapeutic development. Therefore, biophysical approaches are increasingly being employed to probe the structural and dynamical state of proteins, not only in isolation in a test tube, but also in a complex biological environment and even within intact cells. Here, we survey direct and indirect evidence that structural disorder is in fact the physiological state of many proteins in the proteome. The paradigmatic case of α-synuclein is used to illustrate the controversial nature of this topic.
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Affiliation(s)
- Kris Pauwels
- VIB-VUB Center for Structural Biology (CSB), Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Pierre Lebrun
- VIB-VUB Center for Structural Biology (CSB), Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Peter Tompa
- VIB-VUB Center for Structural Biology (CSB), Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium.
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium.
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.
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31
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Battaglia S, Lidschreiber M, Baejen C, Torkler P, Vos SM, Cramer P. RNA-dependent chromatin association of transcription elongation factors and Pol II CTD kinases. eLife 2017; 6. [PMID: 28537551 PMCID: PMC5457138 DOI: 10.7554/elife.25637] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/22/2017] [Indexed: 11/13/2022] Open
Abstract
For transcription through chromatin, RNA polymerase (Pol) II associates with elongation factors (EFs). Here we show that many EFs crosslink to RNA emerging from transcribing Pol II in the yeast Saccharomyces cerevisiae. Most EFs crosslink preferentially to mRNAs, rather than unstable non-coding RNAs. RNA contributes to chromatin association of many EFs, including the Pol II serine 2 kinases Ctk1 and Bur1 and the histone H3 methyltransferases Set1 and Set2. The Ctk1 kinase complex binds RNA in vitro, consistent with direct EF-RNA interaction. Set1 recruitment to genes in vivo depends on its RNA recognition motifs (RRMs). These results strongly suggest that nascent RNA contributes to EF recruitment to transcribing Pol II. We propose that EF-RNA interactions facilitate assembly of the elongation complex on transcribed genes when RNA emerges from Pol II, and that loss of EF-RNA interactions upon RNA cleavage at the polyadenylation site triggers disassembly of the elongation complex. DOI:http://dx.doi.org/10.7554/eLife.25637.001
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Affiliation(s)
- Sofia Battaglia
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Michael Lidschreiber
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Biosciences and Nutrition, Center for Innovative Medicine and Science for Life Laboratory, Novum, Karolinska Institutet, Huddinge, Sweden
| | - Carlo Baejen
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Phillipp Torkler
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Seychelle M Vos
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Biosciences and Nutrition, Center for Innovative Medicine and Science for Life Laboratory, Novum, Karolinska Institutet, Huddinge, Sweden
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Deciphering the mRNP Code: RNA-Bound Determinants of Post-Transcriptional Gene Regulation. Trends Biochem Sci 2017; 42:369-382. [PMID: 28268044 DOI: 10.1016/j.tibs.2017.02.004] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/27/2017] [Accepted: 02/10/2017] [Indexed: 12/16/2022]
Abstract
Eukaryotic cells determine the final protein output of their genetic program not only by controlling transcription but also by regulating the localization, translation and turnover rates of their mRNAs. Ultimately, the fate of any given mRNA is determined by the ensemble of all associated RNA-binding proteins (RBPs), non-coding RNAs and metabolites collectively known as the messenger ribonucleoprotein particle (mRNP). Although many mRNA-associated factors have been identified over the past years, little is known about the composition of individual mRNPs and the cooperation of their constituents. In this review we discuss recent progress that has been made on how this 'mRNP code' is established on individual transcripts and how it is interpreted during gene expression in eukaryotic cells.
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The mRNA capping enzyme of Saccharomyces cerevisiae has dual specificity to interact with CTD of RNA Polymerase II. Sci Rep 2016; 6:31294. [PMID: 27503426 PMCID: PMC4977518 DOI: 10.1038/srep31294] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 07/15/2016] [Indexed: 11/08/2022] Open
Abstract
RNA Polymerase II (RNAPII) uniquely possesses an extended carboxy terminal domain (CTD) on its largest subunit, Rpb1, comprising a repetitive Tyr1Ser2Pro3Thr4 Ser5Pro6Ser7 motif with potential phosphorylation sites. The phosphorylation of the CTD serves as a signal for the binding of various transcription regulators for mRNA biogenesis including the mRNA capping complex. In eukaryotes, the 5 prime capping of the nascent transcript is the first detectable mRNA processing event, and is crucial for the productive transcript elongation. The binding of capping enzyme, RNA guanylyltransferases to the transcribing RNAPII is known to be primarily facilitated by the CTD, phosphorylated at Ser5 (Ser5P). Here we report that the Saccharomyces cerevesiae RNA guanylyltransferase (Ceg1) has dual specificity and interacts not only with Ser5P but also with Ser7P of the CTD. The Ser7 of CTD is essential for the unconditional growth and efficient priming of the mRNA capping complex. The Arg159 and Arg185 of Ceg1 are the key residues that interact with the Ser5P, while the Lys175 with Ser7P of CTD. These interactions appear to be in a specific pattern of Ser5PSer7PSer5P in a tri-heptad CTD (YSPTSPPS YSPTSPSP YSPTSPPS) and provide molecular insights into the Ceg1-CTD interaction for mRNA transcription.
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RNA-Free and Ribonucleoprotein-Associated Influenza Virus Polymerases Directly Bind the Serine-5-Phosphorylated Carboxyl-Terminal Domain of Host RNA Polymerase II. J Virol 2016; 90:6014-6021. [PMID: 27099314 PMCID: PMC4907247 DOI: 10.1128/jvi.00494-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/13/2016] [Indexed: 11/20/2022] Open
Abstract
Influenza viruses subvert the transcriptional machinery of their hosts to synthesize their own viral mRNA. Ongoing transcription by cellular RNA polymerase II (Pol II) is required for viral mRNA synthesis. By a process known as cap snatching, the virus steals short 5′ capped RNA fragments from host capped RNAs and uses them to prime viral transcription. An interaction between the influenza A virus RNA polymerase and the C-terminal domain (CTD) of the large subunit of Pol II has been established, but the molecular details of this interaction remain unknown. We show here that the influenza virus ribonucleoprotein (vRNP) complex binds to the CTD of transcriptionally engaged Pol II. Furthermore, we provide evidence that the viral polymerase binds directly to the serine-5-phosphorylated form of the Pol II CTD, both in the presence and in the absence of viral RNA, and show that this interaction is conserved in evolutionarily distant influenza viruses. We propose a model in which direct binding of the viral RNA polymerase in the context of vRNPs to Pol II early in infection facilitates cap snatching, while we suggest that binding of free viral polymerase to Pol II late in infection may trigger Pol II degradation. IMPORTANCE Influenza viruses cause yearly epidemics and occasional pandemics that pose a threat to human health, as well as represent a large economic burden to health care systems globally. Existing vaccines are not always effective, as they may not exactly match the circulating viruses. Furthermore, there are a limited number of antivirals available, and development of resistance to these is a concern. New measures to combat influenza are needed, but before they can be developed, it is necessary to better understand the molecular interactions between influenza viruses and their host cells. By providing further insights into the molecular details of how influenza viruses hijack the host transcriptional machinery, we aim to uncover novel targets for the development of antivirals.
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Jeronimo C, Collin P, Robert F. The RNA Polymerase II CTD: The Increasing Complexity of a Low-Complexity Protein Domain. J Mol Biol 2016; 428:2607-2622. [DOI: 10.1016/j.jmb.2016.02.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/27/2016] [Accepted: 02/02/2016] [Indexed: 01/18/2023]
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36
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Suh H, Ficarro SB, Kang UB, Chun Y, Marto JA, Buratowski S. Direct Analysis of Phosphorylation Sites on the Rpb1 C-Terminal Domain of RNA Polymerase II. Mol Cell 2016; 61:297-304. [PMID: 26799764 PMCID: PMC4724063 DOI: 10.1016/j.molcel.2015.12.021] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/30/2015] [Accepted: 12/14/2015] [Indexed: 11/20/2022]
Abstract
Dynamic interactions between RNA polymerase II and various mRNA-processing and chromatin-modifying enzymes are mediated by the changing phosphorylation pattern on the C-terminal domain (CTD) of polymerase subunit Rpb1 during different stages of transcription. Phosphorylations within the repetitive heptamer sequence (YSPTSPS) of CTD have primarily been defined using antibodies, but these do not distinguish different repeats or allow comparative quantitation. Using a CTD modified for mass spectrometry (msCTD), we show that Ser5-P and Ser2-P occur throughout the length of CTD and are far more abundant than other phosphorylation sites. msCTD extracted from cells mutated in several CTD kinases or phosphatases showed the expected changes in phosphorylation. Furthermore, msCTD associated with capping enzyme was enriched for Ser5-P while that bound to the transcription termination factor Rtt103 had higher levels of Ser2-P. These results suggest a relatively sparse and simple "CTD code."
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Affiliation(s)
- Hyunsuk Suh
- Department of Biochemical Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology and Blais Proteomics Center, Dana Farber Cancer Institute, Boston, MA 02115, USA
| | - Scott B Ficarro
- Department of Biochemical Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology and Blais Proteomics Center, Dana Farber Cancer Institute, Boston, MA 02115, USA
| | - Un-Beom Kang
- Department of Biochemical Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology and Blais Proteomics Center, Dana Farber Cancer Institute, Boston, MA 02115, USA
| | - Yujin Chun
- Department of Biochemical Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Jarrod A Marto
- Department of Biochemical Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology and Blais Proteomics Center, Dana Farber Cancer Institute, Boston, MA 02115, USA
| | - Stephen Buratowski
- Department of Biochemical Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
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37
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Naftelberg S, Schor IE, Ast G, Kornblihtt AR. Regulation of alternative splicing through coupling with transcription and chromatin structure. Annu Rev Biochem 2015; 84:165-98. [PMID: 26034889 DOI: 10.1146/annurev-biochem-060614-034242] [Citation(s) in RCA: 298] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alternative precursor messenger RNA (pre-mRNA) splicing plays a pivotal role in the flow of genetic information from DNA to proteins by expanding the coding capacity of genomes. Regulation of alternative splicing is as important as regulation of transcription to determine cell- and tissue-specific features, normal cell functioning, and responses of eukaryotic cells to external cues. Its importance is confirmed by the evolutionary conservation and diversification of alternative splicing and the fact that its deregulation causes hereditary disease and cancer. This review discusses the multiple layers of cotranscriptional regulation of alternative splicing in which chromatin structure, DNA methylation, histone marks, and nucleosome positioning play a fundamental role in providing a dynamic scaffold for interactions between the splicing and transcription machineries. We focus on evidence for how the kinetics of RNA polymerase II (RNAPII) elongation and the recruitment of splicing factors and adaptor proteins to chromatin components act in coordination to regulate alternative splicing.
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Affiliation(s)
- Shiran Naftelberg
- Sackler Medical School, Tel Aviv University, Tel Aviv 69978, Israel;
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38
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Emerging Roles of Disordered Sequences in RNA-Binding Proteins. Trends Biochem Sci 2015; 40:662-672. [DOI: 10.1016/j.tibs.2015.08.012] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/21/2015] [Accepted: 08/31/2015] [Indexed: 12/12/2022]
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39
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Structure and two-metal mechanism of a eukaryal nick-sealing RNA ligase. Proc Natl Acad Sci U S A 2015; 112:13868-73. [PMID: 26512110 DOI: 10.1073/pnas.1516536112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
ATP-dependent RNA ligases are agents of RNA repair that join 3'-OH and 5'-PO4 RNA ends. Naegleria gruberi RNA ligase (NgrRnl) exemplifies a family of RNA nick-sealing enzymes found in bacteria, viruses, and eukarya. Crystal structures of NgrRnl at three discrete steps along the reaction pathway-covalent ligase-(lysyl-Nζ)-AMP•Mn(2+) intermediate; ligase•ATP•(Mn(2+))2 Michaelis complex; and ligase•Mn(2+) complex-highlight a two-metal mechanism of nucleotidyl transfer, whereby (i) an enzyme-bound "catalytic" metal coordination complex lowers the pKa of the lysine nucleophile and stabilizes the transition state of the ATP α phosphate; and (ii) a second metal coordination complex bridges the β- and γ-phosphates. The NgrRnl N domain is a distinctively embellished oligonucleotide-binding (OB) fold that engages the γ-phosphate and associated metal complex and orients the pyrophosphate leaving group for in-line catalysis with stereochemical inversion at the AMP phosphate. The unique domain architecture of NgrRnl fortifies the theme that RNA ligases have evolved many times, and independently, by fusions of a shared nucleotidyltransferase domain to structurally diverse flanking modules. The mechanistic insights to lysine adenylylation gained from the NgrRnl structures are likely to apply broadly to the covalent nucleotidyltransferase superfamily of RNA ligases, DNA ligases, and RNA capping enzymes.
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40
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Chandra V, Bortnick A, Murre C. AID targeting: old mysteries and new challenges. Trends Immunol 2015; 36:527-35. [PMID: 26254147 DOI: 10.1016/j.it.2015.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/14/2015] [Accepted: 07/14/2015] [Indexed: 01/09/2023]
Abstract
Activation-induced cytidine deaminase (AID) mediates cytosine deamination and underlies two central processes in antibody diversification: somatic hypermutation and class-switch recombination. AID deamination is not exclusive to immunoglobulin loci; it can instigate DNA lesions in non-immunoglobulin genes and thus stringent checks are in place to constrain and restrict its activity. Recent findings have provided new insights into the mechanisms that target AID activity to specific genomic regions, revealing an involvement for noncoding RNAs associated with polymerase pausing and with enhancer transcription as well as genomic architecture. We review these findings and integrate them into a model for multilevel regulation of AID expression and targeting in immunoglobulin and non-immunoglobulin loci. Within this framework we discuss gaps in understanding, and outline important areas of further research.
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Affiliation(s)
- Vivek Chandra
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0377, USA
| | - Alexandra Bortnick
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0377, USA
| | - Cornelis Murre
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0377, USA.
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41
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Crystal structure of vaccinia virus mRNA capping enzyme provides insights into the mechanism and evolution of the capping apparatus. Structure 2015; 22:452-65. [PMID: 24607143 DOI: 10.1016/j.str.2013.12.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 12/23/2013] [Accepted: 12/30/2013] [Indexed: 02/03/2023]
Abstract
Vaccinia virus capping enzyme is a heterodimer of D1 (844 aa) and D12 (287 aa) polypeptides that executes all three steps in m(7)GpppRNA synthesis. The D1 subunit comprises an N-terminal RNA triphosphatase (TPase)-guanylyltransferase (GTase) module and a C-terminal guanine-N7-methyltransferase (MTase) module. The D12 subunit binds and allosterically stimulates the MTase module. Crystal structures of the complete D1⋅D12 heterodimer disclose the TPase and GTase as members of the triphosphate tunnel metalloenzyme and covalent nucleotidyltransferase superfamilies, respectively, albeit with distinctive active site features. An extensive TPase-GTase interface clamps the GTase nucleotidyltransferase and OB-fold domains in a closed conformation around GTP. Mutagenesis confirms the importance of the TPase-GTase interface for GTase activity. The D1⋅D12 structure complements and rationalizes four decades of biochemical studies of this enzyme, which was the first capping enzyme to be purified and characterized, and provides new insights into the origins of the capping systems of other large DNA viruses.
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42
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Molecular Basis of Transcription-Coupled Pre-mRNA Capping. Mol Cell 2015; 58:1079-89. [PMID: 25959396 DOI: 10.1016/j.molcel.2015.04.004] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 02/27/2015] [Accepted: 03/31/2015] [Indexed: 12/17/2022]
Abstract
Capping is the first step in pre-mRNA processing, and the resulting 5'-RNA cap is required for mRNA splicing, export, translation, and stability. Capping is functionally coupled to transcription by RNA polymerase (Pol) II, but the coupling mechanism remains unclear. We show that efficient binding of the capping enzyme (CE) to transcribing, phosphorylated yeast Pol II (Pol IIp) requires nascent RNA with an unprocessed 5'-triphosphate end. The transcribing Pol IIp-CE complex catalyzes the first two steps of capping, and its analysis by mass spectrometry, cryo-electron microscopy, and protein crosslinking revealed the molecular basis for transcription-coupled pre-mRNA capping. CE docks to the Pol II wall and spans the end of the RNA exit tunnel to position the CE active sites for sequential binding of the exiting RNA 5' end. Thus, the RNA 5' end triggers its own capping when it emerges from Pol II, to ensure seamless RNA protection from 5'-exonucleases during early transcription.
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43
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Meinel DM, Sträßer K. Co-transcriptional mRNP formation is coordinated within a molecular mRNP packaging station in S. cerevisiae. Bioessays 2015; 37:666-77. [PMID: 25801414 PMCID: PMC5054900 DOI: 10.1002/bies.201400220] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In eukaryotes, the messenger RNA (mRNA), the blueprint of a protein‐coding gene, is processed and packaged into a messenger ribonucleoprotein particle (mRNP) by mRNA‐binding proteins in the nucleus. The steps of mRNP formation – transcription, processing, packaging, and the orchestrated release of the export‐competent mRNP from the site of transcription for nuclear mRNA export – are tightly coupled to ensure a highly efficient and regulated process. The importance of highly accurate nuclear mRNP formation is illustrated by the fact that mutations in components of this pathway lead to cellular inviability or to severe diseases in metazoans. We hypothesize that efficient mRNP formation is realized by a molecular mRNP packaging station, which is built by several recruitment platforms and coordinates the individual steps of mRNP formation.
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Affiliation(s)
- Dominik M Meinel
- Bavarian Health and Food Safety Authority, Oberschleißheim, Germany
| | - Katja Sträßer
- Institute of Biochemistry, Justus Liebig University Giessen, Giessen, Germany
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44
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Doamekpor SK, Schwer B, Sanchez AM, Shuman S, Lima CD. Fission yeast RNA triphosphatase reads an Spt5 CTD code. RNA (NEW YORK, N.Y.) 2015; 21:113-123. [PMID: 25414009 PMCID: PMC4274631 DOI: 10.1261/rna.048181.114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 10/24/2014] [Indexed: 06/04/2023]
Abstract
mRNA capping enzymes are directed to nascent RNA polymerase II (Pol2) transcripts via interactions with the carboxy-terminal domains (CTDs) of Pol2 and transcription elongation factor Spt5. Fission yeast RNA triphosphatase binds to the Spt5 CTD, comprising a tandem repeat of nonapeptide motif TPAWNSGSK. Here we report the crystal structure of a Pct1·Spt5-CTD complex, which revealed two CTD docking sites on the Pct1 homodimer that engage TPAWN segments of the motif. Each Spt5 CTD interface, composed of elements from both subunits of the homodimer, is dominated by van der Waals contacts from Pct1 to the tryptophan of the CTD. The bound CTD adopts a distinctive conformation in which the peptide backbone makes a tight U-turn so that the proline stacks over the tryptophan. We show that Pct1 binding to Spt5 CTD is antagonized by threonine phosphorylation. Our results fortify an emerging concept of an "Spt5 CTD code" in which (i) the Spt5 CTD is structurally plastic and can adopt different conformations that are templated by particular cellular Spt5 CTD receptor proteins; and (ii) threonine phosphorylation of the Spt5 CTD repeat inscribes a binary on-off switch that is read by diverse CTD receptors, each in its own distinctive manner.
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Affiliation(s)
- Selom K Doamekpor
- Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Beate Schwer
- Microbiology and Immunology Department, Weill Cornell Medical College, New York, New York 10065, USA
| | - Ana M Sanchez
- Microbiology and Immunology Department, Weill Cornell Medical College, New York, New York 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Christopher D Lima
- Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA Howard Hughes Medical Institute, Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
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45
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46
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Hanes SD. Prolyl isomerases in gene transcription. Biochim Biophys Acta Gen Subj 2014; 1850:2017-34. [PMID: 25450176 DOI: 10.1016/j.bbagen.2014.10.028] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/20/2014] [Accepted: 10/23/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND Peptidyl-prolyl isomerases (PPIases) are enzymes that assist in the folding of newly-synthesized proteins and regulate the stability, localization, and activity of mature proteins. They do so by catalyzing reversible (cis-trans) rotation about the peptide bond that precedes proline, inducing conformational changes in target proteins. SCOPE OF REVIEW This review will discuss how PPIases regulate gene transcription by controlling the activity of (1) DNA-binding transcription regulatory proteins, (2) RNA polymerase II, and (3) chromatin and histone modifying enzymes. MAJOR CONCLUSIONS Members of each family of PPIase (cyclophilins, FKBPs, and parvulins) regulate gene transcription at multiple levels. In all but a few cases, the exact mechanisms remain elusive. Structure studies, development of specific inhibitors, and new methodologies for studying cis/trans isomerization in vivo represent some of the challenges in this new frontier that merges two important fields. GENERAL SIGNIFICANCE Prolyl isomerases have been found to play key regulatory roles in all phases of the transcription process. Moreover, PPIases control upstream signaling pathways that regulate gene-specific transcription during development, hormone response and environmental stress. Although transcription is often rate-limiting in the production of enzymes and structural proteins, post-transcriptional modifications are also critical, and PPIases play key roles here as well (see other reviews in this issue). This article is part of a Special Issue entitled Proline-directed Foldases: Cell Signaling Catalysts and Drug Targets.
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Affiliation(s)
- Steven D Hanes
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E Adams St., Syracuse, NY 13210 USA.
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Doamekpor SK, Sanchez AM, Schwer B, Shuman S, Lima CD. How an mRNA capping enzyme reads distinct RNA polymerase II and Spt5 CTD phosphorylation codes. Genes Dev 2014; 28:1323-36. [PMID: 24939935 PMCID: PMC4066402 DOI: 10.1101/gad.242768.114] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Interactions between RNA guanylyltransferase (GTase) and the C-terminal domain (CTD) repeats of RNA polymerase II (Pol2) and elongation factor Spt5 are thought to orchestrate cotranscriptional capping of nascent mRNAs. The crystal structure of a fission yeast GTase•Pol2 CTD complex reveals a unique docking site on the nucleotidyl transferase domain for an 8-amino-acid Pol2 CTD segment, S5PPSYSPTS5P, bracketed by two Ser5-PO4 marks. Analysis of GTase mutations that disrupt the Pol2 CTD interface shows that at least one of the two Ser5-PO4-binding sites is required for cell viability and that each site is important for cell growth at 37°C. Fission yeast GTase binds the Spt5 CTD at a separate docking site in the OB-fold domain that captures the Trp4 residue of the Spt5 nonapeptide repeat T(1)PAW(4)NSGSK. A disruptive mutation in the Spt5 CTD-binding site of GTase is synthetically lethal with mutations in the Pol2 CTD-binding site, signifying that the Spt5 and Pol2 CTDs cooperate to recruit capping enzyme in vivo. CTD phosphorylation has opposite effects on the interaction of GTase with Pol2 (Ser5-PO4 is required for binding) versus Spt5 (Thr1-PO4 inhibits binding). We propose that the state of Thr1 phosphorylation comprises a binary "Spt5 CTD code" that is read by capping enzyme independent of and parallel to its response to the state of the Pol2 CTD.
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Affiliation(s)
- Selom K Doamekpor
- Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Ana M Sanchez
- Microbiology and Immunology Department, Weill Cornell Medical College, New York, New York 10065, USA
| | - Beate Schwer
- Microbiology and Immunology Department, Weill Cornell Medical College, New York, New York 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Christopher D Lima
- Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA; Howard Hughes Medical Institute, Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
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48
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Ni Z, Xu C, Guo X, Hunter GO, Kuznetsova OV, Tempel W, Marcon E, Zhong G, Guo H, Kuo WHW, Li J, Young P, Olsen JB, Wan C, Loppnau P, El Bakkouri M, Senisterra GA, He H, Huang H, Sidhu SS, Emili A, Murphy S, Mosley AL, Arrowsmith CH, Min J, Greenblatt JF. RPRD1A and RPRD1B are human RNA polymerase II C-terminal domain scaffolds for Ser5 dephosphorylation. Nat Struct Mol Biol 2014; 21:686-695. [PMID: 24997600 PMCID: PMC4124035 DOI: 10.1038/nsmb.2853] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 06/02/2014] [Indexed: 01/16/2023]
Abstract
The RNA polymerase II (RNAPII) C-terminal domain (CTD) heptapeptide repeats (1-YSPTSPS-7) undergo dynamic phosphorylation and dephosphorylation during the transcription cycle to recruit factors that regulate transcription, RNA processing and chromatin modification. We show here that RPRD1A and RPRD1B form homodimers and heterodimers through their coiled-coil domains and interact preferentially via CTD-interaction domains (CIDs) with RNAPII CTD repeats phosphorylated at S2 and S7. Crystal structures of the RPRD1A, RPRD1B and RPRD2 CIDs, alone and in complex with RNAPII CTD phosphoisoforms, elucidate the molecular basis of CTD recognition. In an example of cross-talk between different CTD modifications, our data also indicate that RPRD1A and RPRD1B associate directly with RPAP2 phosphatase and, by interacting with CTD repeats where phospho-S2 and/or phospho-S7 bracket a phospho-S5 residue, serve as CTD scaffolds to coordinate the dephosphorylation of phospho-S5 by RPAP2.
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Affiliation(s)
- Zuyao Ni
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Chao Xu
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Xinghua Guo
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Gerald O Hunter
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Olga V Kuznetsova
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Wolfram Tempel
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Edyta Marcon
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Guoqing Zhong
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Hongbo Guo
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Wei-Hung William Kuo
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Joyce Li
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Peter Young
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan B Olsen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Cuihong Wan
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Peter Loppnau
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Majida El Bakkouri
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | | | - Hao He
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Haiming Huang
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Sachdev S Sidhu
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Emili
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Cheryl H Arrowsmith
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Ontario Cancer Institute, Campbell Family Cancer Research Institute, Toronto, Ontario, Canada
| | - Jinrong Min
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jack F Greenblatt
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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Hsin JP, Li W, Hoque M, Tian B, Manley JL. RNAP II CTD tyrosine 1 performs diverse functions in vertebrate cells. eLife 2014; 3:e02112. [PMID: 24842995 PMCID: PMC4042873 DOI: 10.7554/elife.02112] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The RNA polymerase II largest subunit (Rpb1) contains a unique C-terminal domain (CTD) that plays multiple roles during transcription. The CTD is composed of consensus Y1S2P3T4S5P6S7 repeats, in which Ser, Thr and Tyr residues can all be phosphorylated. Here we report analysis of CTD Tyr1 using genetically tractable chicken DT40 cells. Cells expressing an Rpb1 derivative with all Tyr residues mutated to Phe (Rpb1-Y1F) were inviable. Remarkably, Rpb1-Y1F was unstable, degraded to a CTD-less form; however stability, but not cell viability, was fully rescued by restoration of a single C-terminal Tyr (Rpb1-25F+Y). Cytoplasmic and nucleoplasmic Rpb1 was phosphorylated exclusively on Tyr1, and phosphorylation specifically of Tyr1 prevented CTD degradation by the proteasome in vitro. Tyr1 phosphorylation was also detected on chromatin-associated, hyperphosphorylated Rpb1, consistent with a role in transcription. Indeed, we detected accumulation of upstream antisense (ua) RNAs in Rpb1-25F+Y cells, indicating a role for Tyr1 in uaRNA expression. DOI:http://dx.doi.org/10.7554/eLife.02112.001 When a gene is expressed, the DNA is first transcribed to produce an intermediate molecule called a messenger RNA (mRNA), which is then translated to produce a protein. RNA Polymerase II is an enzyme that makes mRNA molecules in organisms as diverse as plants, animals and yeast. RNA Polymerase II is a complex made of a number of proteins. The largest protein in this complex includes a ‘carboxy-terminal domain’ that has multiple repeats of seven amino acids one after the other. The first amino acid in each repeat, a tyrosine, is referred to as tyrosine-1. Adding various chemical tags to the amino acids in these repeats co-ordinates the steps involved in the transcription of genes. In yeast, for example, adding a phosphate groups to tyrosine-1 seems to help the polymerase to proceed to make long mRNA molecules. However, it is not known what these chemical tags do in humans or other animals. Now Hsin et al. (and independently Descostes, Heidemann et al.) have shown that the same phosphate groups on tyrosine-1 perform functions in vertebrates (animals with backbones) that are different to those performed in yeast. These functions include protecting the carboxy-terminal domain from being broken down inside cells, and transcribing the DNA that is upstream of genes. Hsin et al. replaced tyrosine-1 in RNA Polymerase II from chicken cells with a related amino acid that cannot have phosphate groups added to it. This mutant RNA Polymerase II was unstable and degraded by the molecular machinery in cells that breaks down damaged or unneeded proteins back into amino acids. Hsin et al. also compared the mRNA molecules that are made by the wild-type RNA Polymerase II with those produced by a related mutant. This comparison revealed an unexpected accumulation of RNA molecules that are transcribed in the opposite direction from mRNAs. These RNA molecules, known as ‘upstream antisense RNAs’, have been described only recently. And while the function of these RNAs remains mysterious, the results of Hsin et al. suggest that tyrosine-1 helps to ensure that these RNA molecules are rapidly broken down. The results of Hsin et al. raise a number of important questions, and foremost among these questions is: how do these newly discovered properties of tyrosine-1 contribute to the control of gene expression in animals? Further work is needed to answer this question. DOI:http://dx.doi.org/10.7554/eLife.02112.002
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Affiliation(s)
- Jing-Ping Hsin
- Department of Biological Sciences, Columbia University, New York, United States
| | - Wencheng Li
- Department of Biochemistry and Molecular Biology, Rutgers University New Jersey Medical School, Newark, United States
| | - Mainul Hoque
- Department of Biochemistry and Molecular Biology, Rutgers University New Jersey Medical School, Newark, United States
| | - Bin Tian
- Department of Biochemistry and Molecular Biology, Rutgers University New Jersey Medical School, Newark, United States
| | - James L Manley
- Department of Biological Sciences, Columbia University, New York, United States
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50
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Function and control of RNA polymerase II C-terminal domain phosphorylation in vertebrate transcription and RNA processing. Mol Cell Biol 2014; 34:2488-98. [PMID: 24752900 DOI: 10.1128/mcb.00181-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The C-terminal domain of the RNA polymerase II largest subunit (the Rpb1 CTD) is composed of tandem heptad repeats of the consensus sequence Y(1)S(2)P(3)T(4)S(5)P(6)S(7). We reported previously that Thr 4 is phosphorylated and functions in histone mRNA 3'-end formation in chicken DT40 cells. Here, we have extended our studies on Thr 4 and to other CTD mutations by using these cells. We found that an Rpb1 derivative containing only the N-terminal half of the CTD, as well as a similar derivative containing all-consensus repeats (26r), conferred full viability, while the C-terminal half, with more-divergent repeats, did not, reflecting a strong and specific defect in snRNA 3'-end formation. Mutation in 26r of all Ser 2 (S2A) or Ser 5 (S5A) residues resulted in lethality, while Ser 7 (S7A) mutants were fully viable. While S2A and S5A cells displayed defects in transcription and RNA processing, S7A cells behaved identically to 26r cells in all respects. Finally, we found that Thr 4 was phosphorylated by cyclin-dependent kinase 9 in cells and dephosphorylated both in vitro and in vivo by the phosphatase Fcp1.
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