1
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Waldherr SM, Han M, Saxton AD, Vadset TA, McMillan PJ, Wheeler JM, Liachko NF, Kraemer BC. Endoplasmic reticulum unfolded protein response transcriptional targets of XBP-1s mediate rescue from tauopathy. Commun Biol 2024; 7:903. [PMID: 39060347 PMCID: PMC11282107 DOI: 10.1038/s42003-024-06570-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Pathological tau disrupts protein homeostasis (proteostasis) within neurons in Alzheimer's disease (AD) and related disorders. We previously showed constitutive activation of the endoplasmic reticulum unfolded protein response (UPRER) transcription factor XBP-1s rescues tauopathy-related proteostatic disruption in a tau transgenic Caenorhabditis elegans (C. elegans) model of human tauopathy. XBP-1s promotes clearance of pathological tau, and loss of function of the ATF-6 branch of the UPRER prevents XBP-1s rescue of tauopathy in C. elegans. We conducted transcriptomic analysis of tau transgenic and xbp-1s transgenic C. elegans and found 116 putative target genes significantly upregulated by constitutively active XBP-1s. Among these were five candidate XBP-1s target genes with human orthologs and a previously known association with ATF6 (csp-1, dnj-28, hsp-4, ckb-2, and lipl-3). We examined the functional involvement of these targets in XBP-1s-mediated tauopathy suppression and found loss of function in any one of these genes completely disrupts XBP-1s suppression of tauopathy. Further, we demonstrate upregulation of HSP-4, C. elegans BiP, partially rescues tauopathy independent of other changes in the transcriptional network. Understanding how the UPRER modulates pathological tau accumulation will inform neurodegenerative disease mechanisms and direct further study in mammalian systems with the long-term goal of identifying therapeutic targets in human tauopathies.
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Affiliation(s)
- Sarah M Waldherr
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, 98104, USA
| | - Marina Han
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, 98104, USA
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, 98195, USA
| | - Aleen D Saxton
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, 98108, USA
| | - Taylor A Vadset
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, 98195, USA
| | - Pamela J McMillan
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Jeanna M Wheeler
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, 98108, USA
| | - Nicole F Liachko
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, 98104, USA
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, 98195, USA
| | - Brian C Kraemer
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, 98108, USA.
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, 98104, USA.
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, 98195, USA.
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, 98195, USA.
- Department of Pathology, University of Washington, Seattle, WA, 98195, USA.
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2
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Benoni B, Potužník J, Škríba A, Benoni R, Trylcova J, Tulpa M, Spustová K, Grab K, Mititelu MB, Pačes J, Weber J, Stanek D, Kowalska J, Bednarova L, Keckesova Z, Vopalensky P, Gahurova L, Cahova H. HIV-1 Infection Reduces NAD Capping of Host Cell snRNA and snoRNA. ACS Chem Biol 2024; 19:1243-1249. [PMID: 38747804 PMCID: PMC11197007 DOI: 10.1021/acschembio.4c00151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 06/22/2024]
Abstract
Nicotinamide adenine dinucleotide (NAD) is a critical component of the cellular metabolism and also serves as an alternative 5' cap on various RNAs. However, the function of the NAD RNA cap is still under investigation. We studied NAD capping of RNAs in HIV-1-infected cells because HIV-1 is responsible for the depletion of the NAD/NADH cellular pool and causing intracellular pellagra. By applying the NAD captureSeq protocol to HIV-1-infected and uninfected cells, we revealed that four snRNAs (e.g., U1) and four snoRNAs lost their NAD cap when infected with HIV-1. Here, we provide evidence that the presence of the NAD cap decreases the stability of the U1/HIV-1 pre-mRNA duplex. Additionally, we demonstrate that reducing the quantity of NAD-capped RNA by overexpressing the NAD RNA decapping enzyme DXO results in an increase in HIV-1 infectivity. This suggests that NAD capping is unfavorable for HIV-1 and plays a role in its infectivity.
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Affiliation(s)
- Barbora Benoni
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
- First
Faculty of Medicine, Charles University, Kateřinská 32, 121 08 Prague, Czechia
| | - Jiří
František Potužník
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
- Faculty
of Science, Department of Cell Biology, Charles University, Viničná 7, 121 08 Prague 2, Czechia
| | - Anton Škríba
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - Roberto Benoni
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - Jana Trylcova
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - Matouš Tulpa
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
- Faculty
of Science, Department of Physical and Macromolecular Chemistry, Charles University, Hlavova 8, 121 08 Prague 2, Czechia
| | - Kristína Spustová
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - Katarzyna Grab
- Division
of Biophysics, Faculty of Physics, University
of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Maria-Bianca Mititelu
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
- Faculty
of Science, Department of Cell Biology, Charles University, Viničná 7, 121 08 Prague 2, Czechia
| | - Jan Pačes
- Institute
of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czechia
| | - Jan Weber
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - David Stanek
- Institute
of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czechia
| | - Joanna Kowalska
- Division
of Biophysics, Faculty of Physics, University
of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Lucie Bednarova
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - Zuzana Keckesova
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - Pavel Vopalensky
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
| | - Lenka Gahurova
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
- Department
of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czechia
| | - Hana Cahova
- Institute
of Organic Chemistry and Biochemistry of the CAS, Flemingovo náměstí
2, 160 00 Prague
6, Czechia
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3
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Song Y, Cui J, Zhu J, Kim B, Kuo ML, Potts PR. RNATACs: Multispecific small molecules targeting RNA by induced proximity. Cell Chem Biol 2024; 31:1101-1117. [PMID: 38876100 DOI: 10.1016/j.chembiol.2024.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 05/09/2024] [Accepted: 05/22/2024] [Indexed: 06/16/2024]
Abstract
RNA-targeting small molecules (rSMs) have become an attractive modality to tackle traditionally undruggable proteins and expand the druggable space. Among many innovative concepts, RNA-targeting chimeras (RNATACs) represent a new class of multispecific, induced proximity small molecules that act by chemically bringing RNA targets into proximity with an endogenous RNA effector, such as a ribonuclease (RNase). Depending on the RNA effector, RNATACs can alter the stability, localization, translation, or splicing of the target RNA. Although still in its infancy, this new modality has the potential for broad applications in the future to treat diseases with high unmet need. In this review, we discuss potential advantages of RNATACs, recent progress in the field, and challenges to this cutting-edge technology.
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Affiliation(s)
- Yan Song
- Induced Proximity Platform, Amgen Research, Thousand Oaks, CA 91320, USA.
| | - Jia Cui
- Induced Proximity Platform, Amgen Research, Thousand Oaks, CA 91320, USA
| | - Jiaqiang Zhu
- Induced Proximity Platform, Amgen Research, Thousand Oaks, CA 91320, USA
| | - Boseon Kim
- Induced Proximity Platform, Amgen Research, Thousand Oaks, CA 91320, USA
| | - Mei-Ling Kuo
- Induced Proximity Platform, Amgen Research, Thousand Oaks, CA 91320, USA
| | - Patrick Ryan Potts
- Induced Proximity Platform, Amgen Research, Thousand Oaks, CA 91320, USA.
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4
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Li Y, Wang Q, Xu Y, Li Z. Structures of co-transcriptional RNA capping enzymes on paused transcription complex. Nat Commun 2024; 15:4622. [PMID: 38816438 PMCID: PMC11139899 DOI: 10.1038/s41467-024-48963-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
The 5'-end capping of nascent pre-mRNA represents the initial step in RNA processing, with evidence demonstrating that guanosine addition and 2'-O-ribose methylation occur in tandem with early steps of transcription by RNA polymerase II, especially at the pausing stage. Here, we determine the cryo-EM structures of the paused elongation complex in complex with RNGTT, as well as the paused elongation complex in complex with RNGTT and CMTR1. Our findings show the simultaneous presence of RNGTT and the NELF complex bound to RNA polymerase II. The NELF complex exhibits two conformations, one of which shows a notable rearrangement of NELF-A/D compared to that of the paused elongation complex. Moreover, CMTR1 aligns adjacent to RNGTT on the RNA polymerase II stalk. Our structures indicate that RNGTT and CMTR1 directly bind the paused elongation complex, illuminating the mechanism by which 5'-end capping of pre-mRNA during transcriptional pausing.
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Affiliation(s)
- Yan Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Qianmin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
- The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Ze Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China.
- The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China.
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5
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Yin Y, Yang Z, Sun Y, Yang Y, Zhang X, Zhao X, Tian W, Qiu Y, Yin Y, You F, Lu D. RNA-binding protein PTENα blocks RIG-I activation to prevent viral inflammation. Nat Chem Biol 2024:10.1038/s41589-024-01621-5. [PMID: 38773328 DOI: 10.1038/s41589-024-01621-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 04/15/2024] [Indexed: 05/23/2024]
Abstract
A timely inflammatory response is crucial for early viral defense, but uncontrolled inflammation harms the host. Retinoic acid-inducible gene I (RIG-I) has a pivotal role in detecting RNA viruses, yet the regulatory mechanisms governing its sensitivity remain elusive. Here we identify PTENα, an N-terminally extended form of PTEN, as an RNA-binding protein with a preference for the CAUC(G/U)UCAU motif. Using both in vivo and in vitro viral infection assays, we demonstrated that PTENα restricted the host innate immune response, relying on its RNA-binding capacity and phosphatase activity. Mechanistically, PTENα directly bound to viral RNA and enzymatically converted its 5'-triphosphate to 5'-monophosphate, thereby reducing RIG-I sensitivity. Physiologically, brain-intrinsic PTENα exerted protective effects against viral inflammation, while peripheral PTENα restricted host antiviral immunity and, to some extent, promoted viral replication. Collectively, our findings underscore the significance of PTENα in modulating viral RNA- and RIG-I-mediated immune recognition, offering potential therapeutic implications for infectious diseases.
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Affiliation(s)
- Yue Yin
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Zeliang Yang
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Yizhe Sun
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Ying Yang
- Department of Blood Transfusion, Peking University People's Hospital, Beijing, P.R. China
| | - Xin Zhang
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Xuyang Zhao
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Wenyu Tian
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Yaruo Qiu
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Yuxin Yin
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China.
| | - Fuping You
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China.
| | - Dan Lu
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China.
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6
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Rambout X, Maquat LE. Nuclear mRNA decay: regulatory networks that control gene expression. Nat Rev Genet 2024:10.1038/s41576-024-00712-2. [PMID: 38637632 DOI: 10.1038/s41576-024-00712-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2024] [Indexed: 04/20/2024]
Abstract
Proper regulation of mRNA production in the nucleus is critical for the maintenance of cellular homoeostasis during adaptation to internal and environmental cues. Over the past 25 years, it has become clear that the nuclear machineries governing gene transcription, pre-mRNA processing, pre-mRNA and mRNA decay, and mRNA export to the cytoplasm are inextricably linked to control the quality and quantity of mRNAs available for translation. More recently, an ever-expanding diversity of new mechanisms by which nuclear RNA decay factors finely tune the expression of protein-encoding genes have been uncovered. Here, we review the current understanding of how mammalian cells shape their protein-encoding potential by regulating the decay of pre-mRNAs and mRNAs in the nucleus.
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Affiliation(s)
- Xavier Rambout
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA.
- Center for RNA Biology, University of Rochester, Rochester, NY, USA.
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA.
- Center for RNA Biology, University of Rochester, Rochester, NY, USA.
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7
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He F, Jacobson A. Eukaryotic mRNA decapping factors: molecular mechanisms and activity. FEBS J 2023; 290:5057-5085. [PMID: 36098474 PMCID: PMC10008757 DOI: 10.1111/febs.16626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/11/2022] [Accepted: 09/12/2022] [Indexed: 11/30/2022]
Abstract
Decapping is the enzymatic removal of 5' cap structures from mRNAs in eukaryotic cells. Cap structures normally enhance mRNA translation and stability, and their excision commits an mRNA to complete 5'-3' exoribonucleolytic digestion and generally ends the physical and functional cellular presence of the mRNA. Decapping plays a pivotal role in eukaryotic cytoplasmic mRNA turnover and is a critical and highly regulated event in multiple 5'-3' mRNA decay pathways, including general 5'-3' decay, nonsense-mediated mRNA decay (NMD), AU-rich element-mediated mRNA decay, microRNA-mediated gene silencing, and targeted transcript-specific mRNA decay. In the yeast Saccharomyces cerevisiae, mRNA decapping is carried out by a single Dcp1-Dcp2 decapping enzyme in concert with the accessory activities of specific regulators commonly known as decapping activators or enhancers. These regulatory proteins include the general decapping activators Edc1, 2, and 3, Dhh1, Scd6, Pat1, and the Lsm1-7 complex, as well as the NMD-specific factors, Upf1, 2, and 3. Here, we focus on in vivo mRNA decapping regulation in yeast. We summarize recently uncovered molecular mechanisms that control selective targeting of the yeast decapping enzyme and discuss new roles for specific decapping activators in controlling decapping enzyme targeting, assembly of target-specific decapping complexes, and the monitoring of mRNA translation. Further, we discuss the kinetic contribution of mRNA decapping for overall decay of different substrate mRNAs and highlight experimental evidence pointing to the functional coordination and physical coupling between events in mRNA deadenylation, decapping, and 5'-3' exoribonucleolytic decay.
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Affiliation(s)
- Feng He
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01655
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01655
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8
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Xu W, Li X. Regulation of Pol II Pausing during Daily Gene Transcription in Mouse Liver. BIOLOGY 2023; 12:1107. [PMID: 37626993 PMCID: PMC10452108 DOI: 10.3390/biology12081107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/20/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023]
Abstract
Cell autonomous circadian oscillation is present in central and various peripheral tissues. The intrinsic tissue clock and various extrinsic cues drive gene expression rhythms. Transcription regulation is thought to be the main driving force for gene rhythms. However, how transcription rhythms arise remains to be fully characterized due to the fact that transcription is regulated at multiple steps. In particular, Pol II recruitment, pause release, and premature transcription termination are critical regulatory steps that determine the status of Pol II pausing and transcription output near the transcription start site (TSS) of the promoter. Recently, we showed that Pol II pausing exhibits genome-wide changes during daily transcription in mouse liver. In this article, we review historical as well as recent findings on the regulation of transcription rhythms by the circadian clock and other transcription factors, and the potential limitations of those results in explaining rhythmic transcription at the TSS. We then discuss our results on the genome-wide characteristics of daily changes in Pol II pausing, the possible regulatory mechanisms involved, and their relevance to future research on circadian transcription regulation.
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Affiliation(s)
| | - Xiaodong Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China;
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9
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Lukaszewicz M, Mrozek AF, Bojarska E, Stelmach J, Stepinski J, Darzynkiewicz E. Contribution of Nudt12 enzyme to differentially methylated dinucleotides of 5'RNA cap structure. Biochim Biophys Acta Gen Subj 2023:130400. [PMID: 37301333 DOI: 10.1016/j.bbagen.2023.130400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/17/2023] [Accepted: 06/04/2023] [Indexed: 06/12/2023]
Abstract
Recent findings have substantially broadened our knowledge about the diversity of modifications of the 5'end of RNAs, an issue generally attributed to mRNA cap structure (m7GpppN). Nudt12 is one of the recently described new enzymatic activities involved in cap metabolism. However, in contrast to its roles in metabolite-cap turnover (e.g., NAD-cap) and NADH/NAD metabolite hydrolysis, little is known regarding its hydrolytic activity towards dinucleotide cap structures. In order to gain further insight into this Nudt12 activity, comprehensive analysis with a spectrum of cap-like dinucleotides was performed with respect to different nucleotide types adjacent to the (m7)G moiety and its methylation status. Among the tested compounds, GpppA, GpppAm, and Gpppm6Am were identified as novel potent Nudt12 substrates, with KM values in the same range as that of NADH. Interestingly, substrate inhibition of Nudt12 catalytic activity was detected in the case of the GpppG dinucleotide, a phenomenon not reported to date. Finally, comparison of Nudt12 with DcpS and Nud16, two other enzymes with known activity on dinucleotide cap structures, revealed their overlapping and more specific substrates. Altogether, these findings provide a basis for clarifying the role of Nudt12 in cap-like dinucleotide turnover.
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Affiliation(s)
- Maciej Lukaszewicz
- Department of Biophysics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - Aleksandra-Ferenc Mrozek
- Department of Biophysics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Elzbieta Bojarska
- Department of Biophysics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Joanna Stelmach
- Department of Biophysics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Janusz Stepinski
- Department of Biophysics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Edward Darzynkiewicz
- Department of Biophysics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland; Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
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10
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Ramdas P, Chande A. SERINC5 Mediates a Postintegration Block to HIV-1 Gene Expression in Macrophages. mBio 2023; 14:e0016623. [PMID: 36976020 PMCID: PMC10127607 DOI: 10.1128/mbio.00166-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 03/01/2023] [Indexed: 03/29/2023] Open
Abstract
HIV-1 antagonizes SERINC5 by redundant mechanisms, primarily through Nef and additionally via envelope glycoprotein. Paradoxically, HIV-1 preserves Nef function to ensure the exclusion of SERINC5 from virion incorporation regardless of the availability of envelope that can confer resistance, suggesting additional roles of the virion-incorporated host factor. Here, we report an unusual mode of SERINC5 action in inhibiting viral gene expression. This inhibition is observed only in the myeloid lineage cells but not in the cells of epithelial or lymphoid origin. We found that SERINC5-bearing viruses induce the expression of RPL35 and DRAP1 in macrophages, and these host proteins intercept HIV-1 Tat from binding to and recruiting a mammalian capping enzyme (MCE1) to the HIV-1 transcriptional complex. As a result, uncapped viral transcripts are synthesized, leading to the inhibition of viral protein synthesis and subsequent progeny virion biogenesis. Cell-type-specific inhibition of HIV-1 gene expression thus exemplifies a novel antiviral function of virion-incorporated SERINC5. IMPORTANCE In addition to Nef, HIV-1 envelope glycoprotein has been shown to modulate SERINC5-mediated inhibition. Counterintuitively, Nef from the same isolates preserves the ability to prevent SERINC5 incorporation into virions, implying additional functions of the host protein. We identify that virion-associated SERINC5 can manifest an antiviral mechanism independent of the envelope glycoprotein to regulate HIV-1 gene expression in macrophages. This mechanism is exhibited by affecting the viral RNA capping and is plausibly adopted by the host to overcome the envelope glycoprotein-mediated resistance to SERINC5 restriction.
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Affiliation(s)
- Pavitra Ramdas
- Molecular Virology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh, India
| | - Ajit Chande
- Molecular Virology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh, India
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11
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Huang J, Liu X, Sun Y, Li Z, Lin MH, Hamilton K, Mandel CR, Sandmeir F, Conti E, Oyala PH, Tong L. An examination of the metal ion content in the active sites of human endonucleases CPSF73 and INTS11. J Biol Chem 2023; 299:103047. [PMID: 36822327 PMCID: PMC10064220 DOI: 10.1016/j.jbc.2023.103047] [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: 01/19/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/23/2023] Open
Abstract
Human cleavage and polyadenylation specificity factor (CPSF)73 (also known as CPSF3) is the endoribonuclease that catalyzes the cleavage reaction for the 3'-end processing of pre-mRNAs. The active site of CPSF73 is located at the interface between a metallo-β-lactamase domain and a β-CASP domain. Two metal ions are coordinated by conserved residues, five His and two Asp, in the active site, and they are critical for the nuclease reaction. The metal ions have long been thought to be zinc ions, but their exact identity has not been examined. Here we present evidence from inductively coupled plasma mass spectrometry and X-ray diffraction analyses that a mixture of metal ions, including Fe, Zn, and Mn, is present in the active site of CPSF73. The abundance of the various metal ions is different in samples prepared from different expression hosts. Zinc is present at less than 20% abundance in a sample expressed in insect cells, but the sample is active in cleaving a pre-mRNA substrate in a reconstituted canonical 3'-end processing machinery. Zinc is present at 75% abundance in a sample expressed in human cells, which has comparable endonuclease activity. We also observe a mixture of metal ions in the active site of the CPSF73 homolog INTS11, the endonuclease for Integrator. Taken together, our results provide further insights into the role of metal ions in the activity of CPSF73 and INTS11 for RNA 3'-end processing.
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Affiliation(s)
- Ji Huang
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Xiangyang Liu
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Yadong Sun
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Zhuang Li
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Min-Han Lin
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Keith Hamilton
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Corey R Mandel
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Felix Sandmeir
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Elena Conti
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Paul H Oyala
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, New York, USA.
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12
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Xiao C, Li K, Hua J, He Z, Zhang F, Li Q, Zhang H, Yang L, Pan S, Cai Z, Yu Z, Wong KB, Xia Y. Arabidopsis DXO1 activates RNMT1 to methylate the mRNA guanosine cap. Nat Commun 2023; 14:202. [PMID: 36639378 PMCID: PMC9839713 DOI: 10.1038/s41467-023-35903-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/06/2023] [Indexed: 01/15/2023] Open
Abstract
Eukaryotic messenger RNA (mRNA) typically contains a methylated guanosine (m7G) cap, which mediates major steps of mRNA metabolism. Recently, some RNAs in both prokaryotic and eukaryotic organisms have been found to carry a non-canonical cap such as the NAD cap. Here we report that Arabidopsis DXO family protein AtDXO1, which was previously known to be a decapping enzyme for NAD-capped RNAs (NAD-RNA), is an essential component for m7G capping. AtDXO1 associates with and activates RNA guanosine-7 methyltransferase (AtRNMT1) to catalyze conversion of the guanosine cap to the m7G cap. AtRNMT1 is an essential gene. Partial loss-of-function mutations of AtRNMT1 and knockout mutation of AtDXO1 reduce m7G-capped mRNA but increase G-capped mRNAs, leading to similar pleiotropic phenotypes, whereas overexpression of AtRNMT1 partially restores the atdxo1 phenotypes. This work reveals an important mechanism in m7G capping in plants by which the NAD-RNA decapping enzyme AtDXO1 is required for efficient guanosine cap methylation.
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Affiliation(s)
- Chen Xiao
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China
| | - Kaien Li
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China
| | - Jingmin Hua
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China
| | - Zhao He
- State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong SAR, China
| | - Feng Zhang
- State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong SAR, China
| | - Qiongfang Li
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China
| | - Hailei Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China
| | - Lei Yang
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Shuying Pan
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong SAR, China.
| | - Zhiling Yu
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Kam-Bo Wong
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China. .,State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong SAR, China. .,State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.
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13
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Mattay J. Noncanonical metabolite RNA caps: Classification, quantification, (de)capping, and function. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1730. [PMID: 35675554 DOI: 10.1002/wrna.1730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/11/2022] [Accepted: 03/15/2022] [Indexed: 06/15/2023]
Abstract
The 5' cap of eukaryotic mRNA is a hallmark for cellular functions from mRNA stability to translation. However, the discovery of novel 5'-terminal RNA caps derived from cellular metabolites has challenged this long-standing singularity in both eukaryotes and prokaryotes. Reminiscent of the 7-methylguanosine (m7G) cap structure, these noncanonical caps originate from abundant coenzymes such as NAD, FAD, or CoA and from metabolites like dinucleoside polyphosphates (NpnN). As of now, the significance of noncanonical RNA caps is elusive: they differ for individual transcripts, occur in distinct types of RNA, and change in response to environmental stimuli. A thorough comparison of their prevalence, quantity, and characteristics is indispensable to define the distinct classes of metabolite-capped RNAs. This is achieved by a structured analysis of all present studies covering functional, quantitative, and sequencing data which help to uncover their biological impact. The biosynthetic strategies of noncanonical RNA capping and the elaborate decapping machinery reveal the regulation and turnover of metabolite-capped RNAs. With noncanonical capping being a universal and ancient phenomenon, organisms have developed diverging strategies to adapt metabolite-derived caps to their metabolic needs, but ultimately to establish noncanonical RNA caps as another intriguing layer of RNA regulation. This article is categorized under: RNA Processing > Capping and 5' End Modifications RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Turnover and Surveillance > Regulation of RNA Stability.
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Affiliation(s)
- Johanna Mattay
- Institute of Biochemistry, University of Münster, Münster, Germany
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14
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Panigrahi M, Palmer MA, Wilson JA. MicroRNA-122 Regulation of HCV Infections: Insights from Studies of miR-122-Independent Replication. Pathogens 2022; 11:1005. [PMID: 36145436 PMCID: PMC9504723 DOI: 10.3390/pathogens11091005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/18/2022] Open
Abstract
Despite the advancement in antiviral therapy, Hepatitis C remains a global health challenge and one of the leading causes of hepatitis related deaths worldwide. Hepatitis C virus, the causative agent, is a positive strand RNA virus that requires a liver specific microRNA called miR-122 for its replication. Unconventional to the canonical role of miRNAs in translation suppression by binding to 3'Untranslated Region (UTR) of messenger RNAs, miR-122 binds to two sites on the 5'UTR of viral genome and promotes viral propagation. In this review, we describe the unique relationship between the liver specific microRNA and HCV, the current knowledge on the mechanisms by which the virus uses miR-122 to promote the virus life cycle, and how miR-122 impacts viral tropism and pathogenesis. We will also discuss the use of anti-miR-122 therapy and its impact on viral evolution of miR-122-independent replication. This review further provides insight into how viruses manipulate host factors at the initial stage of infection to establish a successful infection.
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Affiliation(s)
| | | | - Joyce A. Wilson
- Department of Biochemistry, Microbiology, and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
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15
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Drazkowska K, Tomecki R, Warminski M, Baran N, Cysewski D, Depaix A, Kasprzyk R, Kowalska J, Jemielity J, Sikorski P. 2'-O-Methylation of the second transcribed nucleotide within the mRNA 5' cap impacts the protein production level in a cell-specific manner and contributes to RNA immune evasion. Nucleic Acids Res 2022; 50:9051-9071. [PMID: 36018811 PMCID: PMC9458431 DOI: 10.1093/nar/gkac722] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/02/2022] [Accepted: 08/16/2022] [Indexed: 12/24/2022] Open
Abstract
In mammals, m7G-adjacent nucleotides undergo extensive modifications. Ribose of the first or first and second transcribed nucleotides can be subjected to 2'-O-methylation to form cap1 or cap2, respectively. When the first transcribed nucleotide is 2'-O-methylated adenosine, it can be additionally modified to N6,2'-O-dimethyladenosine (m6Am). Recently, the crucial role of cap1 in distinguishing between 'self' and 'non-self' in mammalian cells during viral infection was revealed. Here, we attempted to understand the impact of cap methylations on RNA-related processes. Therefore, we synthesized tetranucleotide cap analogues and used them for RNA capping during in vitro transcription. Using this tool, we found that 2'-O-methylation of the second transcribed nucleotide within the mRNA 5' cap influences protein production levels in a cell-specific manner. This modification can strongly hamper protein biosynthesis or have no influence on protein production levels, depending on the cell line. Interestingly, 2'-O-methylation of the second transcribed nucleotide and the presence of m6Am as the first transcribed nucleotide serve as determinants that define transcripts as 'self' and contribute to transcript escape from the host innate immune response. Additionally, cap methylation status does not influence transcript affinity towards translation initiation factor eIF4E or in vitro susceptibility to decapping by DCP2; however, we observe the resistance of cap2-RNA to DXO (decapping exoribonuclease)-mediated decapping and degradation.
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Affiliation(s)
- Karolina Drazkowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Rafal Tomecki
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Marcin Warminski
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Natalia Baran
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland,Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Dominik Cysewski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland,Clinical Research Centre, Medical University of Bialystok, M. Sklodowskiej-Curie 24a, 15-276 Bialystok, Poland
| | - Anaïs Depaix
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Renata Kasprzyk
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Joanna Kowalska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Jacek Jemielity
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Pawel J Sikorski
- To whom correspondence should be addressed. Tel: +48 22 55 43775; Fax: +48 22 55 43771;
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16
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Doamekpor SK, Sharma S, Kiledjian M, Tong L. Recent insights into noncanonical 5' capping and decapping of RNA. J Biol Chem 2022; 298:102171. [PMID: 35750211 PMCID: PMC9283932 DOI: 10.1016/j.jbc.2022.102171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 11/30/2022] Open
Abstract
The 5' N7-methylguanosine cap is a critical modification for mRNAs and many other RNAs in eukaryotic cells. Recent studies have uncovered an RNA 5' capping quality surveillance mechanism, with DXO/Rai1 decapping enzymes removing incomplete caps and enabling the degradation of the RNAs, in a process we also refer to as "no-cap decay." It has also been discovered recently that RNAs in eukaryotes, bacteria, and archaea can have noncanonical caps (NCCs), which are mostly derived from metabolites and cofactors such as NAD, FAD, dephospho-CoA, UDP-glucose, UDP-N-acetylglucosamine, and dinucleotide polyphosphates. These NCCs can affect RNA stability, mitochondrial functions, and possibly mRNA translation. The DXO/Rai1 enzymes and selected Nudix (nucleotide diphosphate linked to X) hydrolases have been shown to remove NCCs from RNAs through their deNADding, deFADding, deCoAping, and related activities, permitting the degradation of the RNAs. In this review, we summarize the recent discoveries made in this exciting new area of RNA biology.
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Affiliation(s)
- Selom K. Doamekpor
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Sunny Sharma
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey, USA
| | - Megerditch Kiledjian
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey, USA.
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, New York, USA.
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17
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Łabędzka-Dmoch K, Rażew M, Gapińska M, Piątkowski J, Kolondra A, Salmonowicz H, Wenda JM, Nowotny M, Golik P. The Pet127 protein is a mitochondrial 5'-to-3' exoribonuclease from the PD-(D/E)XK superfamily involved in RNA maturation and intron degradation in yeasts. RNA (NEW YORK, N.Y.) 2022; 28:711-728. [PMID: 35197365 PMCID: PMC9014873 DOI: 10.1261/rna.079083.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 01/31/2022] [Indexed: 06/01/2023]
Abstract
Pet127 is a mitochondrial protein found in multiple eukaryotic lineages, but absent from several taxa, including plants and animals. Distant homology suggests that it belongs to the divergent PD-(D/E)XK superfamily which includes various nucleases and related proteins. Earlier yeast genetics experiments suggest that it plays a nonessential role in RNA degradation and 5' end processing. Our phylogenetic analysis suggests that it is a primordial eukaryotic invention that was retained in diverse groups, and independently lost several times in the evolution of other organisms. We demonstrate for the first time that the fungal Pet127 protein in vitro is a processive 5'-to-3' exoribonuclease capable of digesting various substrates in a sequence nonspecific manner. Mutations in conserved residues essential in the PD-(D/E)XK superfamily active site abolish the activity of Pet127. Deletion of the PET127 gene in the pathogenic yeast Candida albicans results in a moderate increase in the steady-state levels of several transcripts and in accumulation of unspliced precursors and intronic sequences of three introns. Mutations in the active site residues result in a phenotype identical to that of the deletant, confirming that the exoribonuclease activity is related to the physiological role of the Pet127 protein. Pet127 activity is, however, not essential for maintaining the mitochondrial respiratory activity in C. albicans.
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Affiliation(s)
- Karolina Łabędzka-Dmoch
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw 02-106, Poland
| | - Michal Rażew
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Marta Gapińska
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Jakub Piątkowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw 02-106, Poland
| | - Adam Kolondra
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw 02-106, Poland
| | - Hanna Salmonowicz
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw 02-106, Poland
- Laboratory of Metabolic Quality Control, IMOL, Polish Academy of Sciences, Warsaw 00-783, Poland
| | - Joanna M Wenda
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw 02-106, Poland
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Paweł Golik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw 02-106, Poland
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
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18
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Hurtig JE, van Hoof A. Yeast Dxo1 is required for 25S rRNA maturation and acts as a transcriptome-wide distributive exonuclease. RNA (NEW YORK, N.Y.) 2022; 28:657-667. [PMID: 35140172 PMCID: PMC9014881 DOI: 10.1261/rna.078952.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 01/24/2022] [Indexed: 05/03/2023]
Abstract
The Dxo1/Rai1/DXO family of decapping and exonuclease enzymes can catalyze the in vitro removal of chemically diverse 5' ends from RNA. Specifically, these enzymes act poorly on RNAs with a canonical 7mGpppN cap, but instead prefer RNAs with a triphosphate, monophosphate, hydroxyl, or nonconventional cap. In each case, these enzymes generate an RNA with a 5' monophosphate, which is then thought to be further degraded by Rat1/Xrn1 5' exoribonucleases. For most Dxo1/Rai1/DXO family members, it is not known which of these activities is most important in vivo. Here we describe the in vivo function of the poorly characterized cytoplasmic family member, yeast Dxo1. Using RNA-seq of 5' monophosphate ends, we show that Dxo1 can act as a distributive exonuclease, removing a few nucleotides from endonuclease or decapping products. We also show that Dxo1 is required for the final 5' end processing of 25S rRNA, and that this is the primary role of Dxo1. While Dxo1/Rai1/DXO members were expected to act upstream of Rat1/Xrn1, this order is reversed in 25S rRNA processing, with Dxo1 acting downstream from Rat1. Such a hand-off from a processive to a distributive exonuclease may be a general phenomenon in the precise maturation of RNA ends.
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Affiliation(s)
- Jennifer E Hurtig
- Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Ambro van Hoof
- Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030, USA
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19
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Abstract
The 5'-terminal cap is a fundamental determinant of eukaryotic gene expression which facilitates cap-dependent translation and protects mRNAs from exonucleolytic degradation. Enzyme-directed hydrolysis of the cap (decapping) decisively affects mRNA expression and turnover, and is a heavily regulated event. Following the identification of the decapping holoenzyme (Dcp1/2) over two decades ago, numerous studies revealed the complexity of decapping regulation across species and cell types. A conserved set of Dcp1/2-associated proteins, implicated in decapping activation and molecular scaffolding, were identified through genetic and molecular interaction studies, and yet their exact mechanisms of action are only emerging. In this review, we discuss the prevailing models on the roles and assembly of decapping co-factors, with considerations of conservation across species and comparison across physiological contexts. We next discuss the functional convergences of decapping machineries with other RNA-protein complexes in cytoplasmic P bodies and compare current views on their impact on mRNA stability and translation. Lastly, we review the current models of decapping activation and highlight important gaps in our current understanding.
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Affiliation(s)
- Elva Vidya
- Goodman Cancer Institute, McGill University, Montréal, QC, Canada
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Thomas F. Duchaine
- Goodman Cancer Institute, McGill University, Montréal, QC, Canada
- Department of Biochemistry, McGill University, Montréal, QC, Canada
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20
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Thompson MG, Sacco MT, Horner SM. How RNA modifications regulate the antiviral response. Immunol Rev 2021; 304:169-180. [PMID: 34405413 PMCID: PMC8616813 DOI: 10.1111/imr.13020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/27/2021] [Accepted: 08/05/2021] [Indexed: 12/25/2022]
Abstract
Induction of the antiviral innate immune response is highly regulated at the RNA level, particularly by RNA modifications. Recent discoveries have revealed how RNA modifications play key roles in cellular surveillance of nucleic acids and in controlling gene expression in response to viral infection. These modifications have emerged as being essential for a functional antiviral response and maintaining cellular homeostasis. In this review, we will highlight these and other discoveries that describe how the antiviral response is controlled by modifications to both viral and cellular RNA, focusing on how mRNA cap modifications, N6-methyladenosine, and RNA editing all contribute to coordinating an efficient response that properly controls viral infection.
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Affiliation(s)
- Matthew G Thompson
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Matthew T Sacco
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Stacy M Horner
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC, USA
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
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21
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Zhou W, Guan Z, Zhao F, Ye Y, Yang F, Yin P, Zhang D. Structural insights into dpCoA-RNA decapping by NudC. RNA Biol 2021; 18:244-253. [PMID: 34074215 PMCID: PMC8677037 DOI: 10.1080/15476286.2021.1936837] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 10/21/2022] Open
Abstract
Various kinds of cap structures, such as m7G, triphosphate groups, NAD and dpCoA, protect the 5' terminus of RNA. The cap structures bond covalently to RNA and affect its stability, translation, and transport. The removal of the caps is mainly executed by Nudix hydrolase family proteins, including Dcp2, RppH and NudC. Numerous efforts have been made to elucidate the mechanism underlying the removal of m7G, triphosphate group, and NAD caps. In contrast, few studies related to the cleavage of the RNA dpCoA cap have been conducted. Here, we report the hydrolytic activity of Escherichia coli NudC towards dpCoA and dpCoA-capped RNA in vitro. We also determined the crystal structure of dimeric NudC in complex with dpCoA at 2.0 Å resolution. Structural analysis revealed that dpCoA is recognized and hydrolysed in a manner similar to NAD. In addition, NudC may also remove other dinucleotide derivative caps of RNA, which comprise the AMP moieties. NudC homologs in Saccharomyces cerevisiae and Arabidopsis thaliana exhibited similar dpCoA decapping (deCoAping) activity. These results together indicate a conserved mechanism underpinning the hydrolysis of dpCoA-capped RNA in both prokaryotes and eukaryotes.
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Affiliation(s)
- Wei Zhou
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Zeyuan Guan
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Fen Zhao
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Yage Ye
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Fang Yang
- State Key Laboratory of Hybid Rice, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Ping Yin
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Delin Zhang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
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22
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Ma T, Gao H, Zhang D, Sun W, Yin Q, Wu L, Zhang T, Xu Z, Wei J, Su Y, Shi Y, Ding D, Yuan L, Dong G, Leng L, Xiang L, Chen S. Genome-Wide Analysis of Light-Regulated Alternative Splicing in Artemisia annua L. FRONTIERS IN PLANT SCIENCE 2021; 12:733505. [PMID: 34659300 PMCID: PMC8511310 DOI: 10.3389/fpls.2021.733505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Artemisinin is currently the most effective ingredient in the treatment of malaria, which is thus of great significance to study the genetic regulation of Artemisia annua. Alternative splicing (AS) is a regulatory process that increases the complexity of transcriptome and proteome. The most common mechanism of alternative splicing (AS) in plant is intron retention (IR). However, little is known about whether the IR isoforms produced by light play roles in regulating biosynthetic pathways. In this work we would explore how the level of AS in A. annua responds to light regulation. We obtained a new dataset of AS by analyzing full-length transcripts using both Illumina- and single molecule real-time (SMRT)-based RNA-seq as well as analyzing AS on various tissues. A total of 5,854 IR isoforms were identified, with IR accounting for the highest proportion (48.48%), affirming that IR is the most common mechanism of AS. We found that the number of up-regulated IR isoforms (1534/1378, blue and red light, respectively) was more than twice that of down-regulated (636/682) after treatment of blue or red light. In the artemisinin biosynthetic pathway, 10 genes produced 16 differentially expressed IR isoforms. This work demonstrated that the differential expression of IR isoforms induced by light has the potential to regulate sesquiterpenoid biosynthesis. This study also provides high accuracy full-length transcripts, which can be a valuable genetic resource for further research of A. annua, including areas of development, breeding, and biosynthesis of active compounds.
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Affiliation(s)
- Tingyu Ma
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
- Key Lab of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Han Gao
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
- School of Life Sciences, Central China Normal University, Wuhan, China
| | - Dong Zhang
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
- College of Agriculture, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Wei Sun
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Qinggang Yin
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Lan Wu
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Tianyuan Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Zhichao Xu
- Key Lab of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jianhe Wei
- Hainan Provincial Key Laboratory of Resources Conservation and Development of Southern Medicine, Hainan Branch of the Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Haikou, China
| | - Yanyan Su
- Amway (China) Botanical R&D Center, Wuxi, China
| | - Yuhua Shi
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Dandan Ding
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Ling Yuan
- Department of Plant and Soil Sciences, Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY, United States
| | | | - Liang Leng
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Li Xiang
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
- Department of Plant and Soil Sciences, Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY, United States
| | - Shilin Chen
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
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23
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Gopalakrishnan R, Winston F. The histone chaperone Spt6 is required for normal recruitment of the capping enzyme Abd1 to transcribed regions. J Biol Chem 2021; 297:101205. [PMID: 34543624 PMCID: PMC8511950 DOI: 10.1016/j.jbc.2021.101205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/20/2021] [Accepted: 09/15/2021] [Indexed: 10/29/2022] Open
Abstract
The histone chaperone Spt6 is involved in promoting elongation of RNA polymerase II (RNAPII), maintaining chromatin structure, regulating cotranscriptional histone modifications, and controlling mRNA processing. These diverse functions of Spt6 are partly mediated through its interactions with RNAPII and other factors in the transcription elongation complex. In this study, we used mass spectrometry to characterize the differences in RNAPII-interacting factors between wildtype cells and those depleted for Spt6, leading to the identification of proteins that depend on Spt6 for their interaction with RNAPII. The altered association of some of these factors could be attributed to changes in steady-state protein levels. However, Abd1, the mRNA cap methyltransferase, had decreased association with RNAPII after Spt6 depletion despite unchanged Abd1 protein levels, showing a requirement for Spt6 in mediating the Abd1-RNAPII interaction. Genome-wide studies showed that Spt6 is required for maintaining the level of Abd1 over transcribed regions, as well as the level of Spt5, another protein known to recruit Abd1 to chromatin. Abd1 levels were particularly decreased at the 5' ends of genes after Spt6 depletion, suggesting a greater need for Spt6 in Abd1 recruitment over these regions. Together, our results show that Spt6 is important in regulating the composition of the transcription elongation complex and reveal a previously unknown function for Spt6 in the recruitment of Abd1.
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Affiliation(s)
| | - Fred Winston
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA.
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24
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Kron NS, Fieber LA. Co-expression analysis identifies neuro-inflammation as a driver of sensory neuron aging in Aplysia californica. PLoS One 2021; 16:e0252647. [PMID: 34116561 PMCID: PMC8195618 DOI: 10.1371/journal.pone.0252647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 05/20/2021] [Indexed: 01/08/2023] Open
Abstract
Aging of the nervous system is typified by depressed metabolism, compromised proteostasis, and increased inflammation that results in cognitive impairment. Differential expression analysis is a popular technique for exploring the molecular underpinnings of neural aging, but technical drawbacks of the methodology often obscure larger expression patterns. Co-expression analysis offers a robust alternative that allows for identification of networks of genes and their putative central regulators. In an effort to expand upon previous work exploring neural aging in the marine model Aplysia californica, we used weighted gene correlation network analysis to identify co-expression networks in a targeted set of aging sensory neurons in these animals. We identified twelve modules, six of which were strongly positively or negatively associated with aging. Kyoto Encyclopedia of Genes analysis and investigation of central module transcripts identified signatures of metabolic impairment, increased reactive oxygen species, compromised proteostasis, disrupted signaling, and increased inflammation. Although modules with immune character were identified, there was no correlation between genes in Aplysia that increased in expression with aging and the orthologous genes in oyster displaying long-term increases in expression after a virus-like challenge. This suggests anti-viral response is not a driver of Aplysia sensory neuron aging.
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Affiliation(s)
- N. S. Kron
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States of America
| | - L. A. Fieber
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States of America
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25
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Wood S, Willbanks A, Cheng JX. The Role of RNA Modifications and RNA-modifying Proteins in Cancer Therapy and Drug Resistance. Curr Cancer Drug Targets 2021; 21:326-352. [PMID: 33504307 DOI: 10.2174/1568009621666210127092828] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/03/2020] [Accepted: 12/03/2020] [Indexed: 11/22/2022]
Abstract
The advent of new genome-wide sequencing technologies has uncovered abnormal RNA modifications and RNA editing in a variety of human cancers. The discovery of reversible RNA N6-methyladenosine (RNA: m6A) by fat mass and obesity-associated protein (FTO) demethylase has led to exponential publications on the pathophysiological functions of m6A and its corresponding RNA modifying proteins (RMPs) in the past decade. Some excellent reviews have summarized the recent progress in this field. Compared to the extent of research into RNA: m6A and DNA 5-methylcytosine (DNA: m5C), much less is known about other RNA modifications and their associated RMPs, such as the role of RNA: m5C and its RNA cytosine methyltransferases (RCMTs) in cancer therapy and drug resistance. In this review, we will summarize the recent progress surrounding the function, intramolecular distribution and subcellular localization of several major RNA modifications, including 5' cap N7-methylguanosine (m7G) and 2'-O-methylation (Nm), m6A, m5C, A-to-I editing, and the associated RMPs. We will then discuss dysregulation of those RNA modifications and RMPs in cancer and their role in cancer therapy and drug resistance.
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Affiliation(s)
- Shaun Wood
- Department of Pathology, Hematopathology Section, University of Chicago, Chicago, IL60637, United States
| | - Amber Willbanks
- Department of Pathology, Hematopathology Section, University of Chicago, Chicago, IL60637, United States
| | - Jason X Cheng
- Department of Pathology, Hematopathology Section, University of Chicago, Chicago, IL60637, United States
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26
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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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27
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Destefanis E, Avşar G, Groza P, Romitelli A, Torrini S, Pir P, Conticello SG, Aguilo F, Dassi E. A mark of disease: how mRNA modifications shape genetic and acquired pathologies. RNA (NEW YORK, N.Y.) 2021; 27:367-389. [PMID: 33376192 PMCID: PMC7962492 DOI: 10.1261/rna.077271.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
RNA modifications have recently emerged as a widespread and complex facet of gene expression regulation. Counting more than 170 distinct chemical modifications with far-reaching implications for RNA fate, they are collectively referred to as the epitranscriptome. These modifications can occur in all RNA species, including messenger RNAs (mRNAs) and noncoding RNAs (ncRNAs). In mRNAs the deposition, removal, and recognition of chemical marks by writers, erasers and readers influence their structure, localization, stability, and translation. In turn, this modulates key molecular and cellular processes such as RNA metabolism, cell cycle, apoptosis, and others. Unsurprisingly, given their relevance for cellular and organismal functions, alterations of epitranscriptomic marks have been observed in a broad range of human diseases, including cancer, neurological and metabolic disorders. Here, we will review the major types of mRNA modifications and editing processes in conjunction with the enzymes involved in their metabolism and describe their impact on human diseases. We present the current knowledge in an updated catalog. We will also discuss the emerging evidence on the crosstalk of epitranscriptomic marks and what this interplay could imply for the dynamics of mRNA modifications. Understanding how this complex regulatory layer can affect the course of human pathologies will ultimately lead to its exploitation toward novel epitranscriptomic therapeutic strategies.
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Affiliation(s)
- Eliana Destefanis
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
- The EPITRAN COST Action Consortium, COST Action CA16120
| | - Gülben Avşar
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Bioengineering, Gebze Technical University, 41400 Kocaeli, Turkey
| | - Paula Groza
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Medical Biosciences, Umeå University, 901 87 Umeå, Sweden
- Wallenberg Center for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Antonia Romitelli
- The EPITRAN COST Action Consortium, COST Action CA16120
- Core Research Laboratory, ISPRO-Institute for Cancer Research, Prevention and Clinical Network, 50139 Firenze, Italy
- Department of Medical Biotechnologies, Università di Siena, 53100 Siena, Italy
| | - Serena Torrini
- The EPITRAN COST Action Consortium, COST Action CA16120
- Core Research Laboratory, ISPRO-Institute for Cancer Research, Prevention and Clinical Network, 50139 Firenze, Italy
- Department of Medical Biotechnologies, Università di Siena, 53100 Siena, Italy
| | - Pınar Pir
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Bioengineering, Gebze Technical University, 41400 Kocaeli, Turkey
| | - Silvestro G Conticello
- The EPITRAN COST Action Consortium, COST Action CA16120
- Core Research Laboratory, ISPRO-Institute for Cancer Research, Prevention and Clinical Network, 50139 Firenze, Italy
- Institute of Clinical Physiology, National Research Council, 56124 Pisa, Italy
| | - Francesca Aguilo
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Medical Biosciences, Umeå University, 901 87 Umeå, Sweden
- Wallenberg Center for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Erik Dassi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
- The EPITRAN COST Action Consortium, COST Action CA16120
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28
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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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29
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Borbolis F, Syntichaki P. Biological implications of decapping: beyond bulk mRNA decay. FEBS J 2021; 289:1457-1475. [PMID: 33660392 DOI: 10.1111/febs.15798] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/21/2021] [Accepted: 03/07/2021] [Indexed: 12/12/2022]
Abstract
It is well established that mRNA steady-state levels do not directly correlate with transcription rate. This is attributed to the multiple post-transcriptional mechanisms, which control both mRNA turnover and translation within eukaryotic cells. One such mechanism is the removal of the 5' end cap structure of RNAs (decapping). This 5' cap plays a fundamental role in cellular functions related to mRNA processing, transport, translation, quality control, and decay, while its chemical modifications influence the fate of cytoplasmic mRNAs. Decapping is a highly controlled process, performed by multiple decapping enzymes, and regulated by complex cellular networks. In this review, we provide an updated synopsis of 5' end modifications and functions, and give an overview of mRNA decapping enzymes, presenting their enzymatic properties. Focusing on DCP2 decapping enzyme, a major component on the 5'-3' mRNA decay pathway, we describe cis-elements and trans-acting factors that affect its activity, substrate specificity, and cellular localization. Finally, we discuss current knowledge on the biological functions of mRNA decapping and decay factors, highlighting the major questions that remain to be addressed.
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Affiliation(s)
- Fivos Borbolis
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research, Athens, Greece
| | - Popi Syntichaki
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research, Athens, Greece
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30
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Moya-Ramírez I, Bouton C, Kontoravdi C, Polizzi K. High resolution biosensor to test the capping level and integrity of mRNAs. Nucleic Acids Res 2021; 48:e129. [PMID: 33152073 PMCID: PMC7736790 DOI: 10.1093/nar/gkaa955] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 09/22/2020] [Accepted: 10/08/2020] [Indexed: 11/21/2022] Open
Abstract
5′ Cap structures are ubiquitous on eukaryotic mRNAs, essential for post-transcriptional processing, translation initiation and stability. Here we describe a biosensor designed to detect the presence of cap structures on mRNAs that is also sensitive to mRNA degradation, so uncapped or degraded mRNAs can be detected in a single step. The biosensor is based on a chimeric protein that combines the recognition and transduction roles in a single molecule. The main feature of this sensor is its simplicity, enabling semi-quantitative analyses of capping levels with minimal instrumentation. The biosensor was demonstrated to detect the capping level on several in vitro transcribed mRNAs. Its sensitivity and dynamic range remained constant with RNAs ranging in size from 250 nt to approximately 2700 nt and the biosensor was able to detect variations in the capping level in increments of at least 20%, with a limit of detection of 2.4 pmol. Remarkably, it also can be applied to more complex analytes, such mRNA vaccines and mRNAs transcribed in vivo. This biosensor is an innovative example of a technology able to detect analytically challenging structures such as mRNA caps. It could find application in a variety of scenarios, from quality analysis of mRNA-based products such as vaccines to optimization of in vitro capping reactions.
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Affiliation(s)
- Ignacio Moya-Ramírez
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.,Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK
| | - Clement Bouton
- Department of Infectious Disease, Imperial College London, London W2 1NY, UK
| | - Cleo Kontoravdi
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Karen Polizzi
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.,Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK
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31
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Luo Y, Schofield JA, Na Z, Hann T, Simon MD, Slavoff SA. Discovery of cellular substrates of human RNA-decapping enzyme DCP2 using a stapled bicyclic peptide inhibitor. Cell Chem Biol 2020; 28:463-474.e7. [PMID: 33357462 DOI: 10.1016/j.chembiol.2020.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/29/2020] [Accepted: 12/04/2020] [Indexed: 01/23/2023]
Abstract
DCP2 is an RNA-decapping enzyme that controls the stability of human RNAs that encode factors functioning in transcription and the immune response. While >1,800 human DCP2 substrates have been identified, compensatory expression changes secondary to genetic ablation of DCP2 have complicated a complete mapping of its regulome. Cell-permeable, selective chemical inhibitors of DCP2 could provide a powerful tool to study DCP2 specificity. Here, we report phage display selection of CP21, a bicyclic peptide ligand to DCP2. CP21 has high affinity and selectivity for DCP2 and inhibits DCP2 decapping activity toward selected RNA substrates in human cells. CP21 increases formation of P-bodies, liquid condensates enriched in intermediates of RNA decay, in a manner that resembles the deletion or mutation of DCP2. We used CP21 to identify 76 previously unreported DCP2 substrates. This work demonstrates that DCP2 inhibition can complement genetic approaches to study RNA decay.
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Affiliation(s)
- Yang Luo
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Chemical Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Jeremy A Schofield
- Chemical Biology Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06529, USA
| | - Zhenkun Na
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Chemical Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Tanja Hann
- Yale Combined Program in the Biological and Biomedical Sciences, Yale University, New Haven, CT 06520, USA
| | - Matthew D Simon
- Chemical Biology Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06529, USA
| | - Sarah A Slavoff
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Chemical Biology Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06529, USA.
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32
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Abstract
Here we review data suggestive of a role for RNA-binding proteins in vertebrate immunity. We focus on the products of genes found in the class III region of the Major Histocompatibility Complex. Six of these genes, DDX39B (aka BAT1), DXO, LSM2, NELFE, PRRC2A (aka BAT2), and SKIV2L, encode RNA-binding proteins with clear roles in post-transcriptional gene regulation and RNA surveillance. These genes are likely to have important functions in immunity and are associated with autoimmune diseases.
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Affiliation(s)
- Geraldine Schott
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA.,Biochemistry and Molecular Biology Graduate Program, University of Texas Medical Branch, Galveston, Texas, USA
| | - Mariano A Garcia-Blanco
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA.,Programme in Infectious Diseases, Duke-NUS Medical School, Singapore.,Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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33
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Pelletier J, Schmeing TM, Sonenberg N. The multifaceted eukaryotic cap structure. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1636. [PMID: 33300197 DOI: 10.1002/wrna.1636] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/16/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022]
Abstract
The 5' cap structure is added onto RNA polymerase II transcripts soon after initiation of transcription and modulates several post-transcriptional regulatory events involved in RNA maturation. It is also required for stimulating translation initiation of many cytoplasmic mRNAs and serves to protect mRNAs from degradation. These functional properties of the cap are mediated by several cap binding proteins (CBPs) involved in nuclear and cytoplasmic gene expression steps. The role that CBPs play in gene regulation, as well as the biophysical nature by which they recognize the cap, is quite intricate. Differences in mechanisms of capping as well as nuances in cap recognition speak to the potential of targeting these processes for drug development. In this review, we focus on recent findings concerning the cap epitranscriptome, our understanding of cap binding by different CBPs, and explore therapeutic targeting of CBP-cap interaction. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Processing > Capping and 5' End Modifications Translation > Translation Mechanisms.
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Affiliation(s)
- Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Department of Oncology, McGill University, Montreal, Quebec, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada.,Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
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34
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Xie S, Chen W, Chen K, Chang Y, Yang F, Lin A, Shu Q, Zhou T, Yan X. Emerging roles of RNA methylation in gastrointestinal cancers. Cancer Cell Int 2020; 20:585. [PMID: 33372610 PMCID: PMC7720447 DOI: 10.1186/s12935-020-01679-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/26/2020] [Indexed: 12/15/2022] Open
Abstract
RNA methylation has emerged as a fundamental process in epigenetic regulation. Accumulating evidences indicate that RNA methylation is essential for many biological functions, and its dysregulation is associated with human cancer progression, particularly in gastrointestinal cancers. RNA methylation has a variety of biological properties, including N6-methyladenosine (m6A), 2-O-dimethyladenosine (m6Am), N1-methyladenosine (m1A), 5-methylcytosine (m5C) and 7-methyl guanosine (m7G). Dynamic and reversible methylation on RNA is mediated by RNA modifying proteins called "writers" (methyltransferases) and "erasers" (demethylases). "Readers" (modified RNA binding proteins) recognize and bind to RNA methylation sites, which influence the splicing, stability or translation of modified RNAs. Herein, we summarize the biological functions and mechanisms of these well-known RNA methylations, especially focusing on the roles of m6A in gastrointestinal cancer development.
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Affiliation(s)
- Shanshan Xie
- The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310052, China.,Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Wenwen Chen
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Kanghua Chen
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yongxia Chang
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Feng Yang
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Aifu Lin
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Qiang Shu
- The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310052, China
| | - Tianhua Zhou
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
| | - Xiaoyi Yan
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China.
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35
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Out or decay: fate determination of nuclear RNAs. Essays Biochem 2020; 64:895-905. [DOI: 10.1042/ebc20200005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/12/2020] [Accepted: 08/24/2020] [Indexed: 02/08/2023]
Abstract
Abstract
In eukaryotes, RNAs newly synthesized by RNA polymerase II (RNAPII) undergo several processing steps prior to transport to the cytoplasm. It has long been known that RNAs with defects in processing or export are removed in the nucleus. Recent studies revealed that RNAs without apparent defects are also subjected to nuclear degradation, indicating that nuclear RNA fate is determined in a more complex and dynamic way than previously thought. Nuclear RNA sorting directly determines the quality and quantity of RNA pools for future translation and thus is of significant importance. In this essay, we will summarize recent studies on this topic, mainly focusing on findings in mammalian system, and discuss about important remaining questions and possible biological relevance for nuclear RNA fate determination.
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36
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Alternative Polyadenylation: a new frontier in post transcriptional regulation. Biomark Res 2020; 8:67. [PMID: 33292571 PMCID: PMC7690165 DOI: 10.1186/s40364-020-00249-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022] Open
Abstract
Polyadenylation of pre-messenger RNA (pre-mRNA) specific sites and termination of their downstream transcriptions are signaled by unique sequence motif structures such as AAUAAA and its auxiliary elements. Alternative polyadenylation (APA) is an important post-transcriptional regulatory mechanism that processes RNA products depending on its 3'-untranslated region (3'-UTR) specific sequence signal. APA processing can generate several mRNA isoforms from a single gene, which may have different biological functions on their target gene. As a result, cellular genomic stability, proliferation capability, and transformation feasibility could all be affected. Furthermore, APA modulation regulates disease initiation and progression. APA status could potentially act as a biomarker for disease diagnosis, severity stratification, and prognosis forecast. While the advance of modern throughout technologies, such as next generation-sequencing (NGS) and single-cell sequencing techniques, have enriched our knowledge about APA, much of APA biological process is unknown and pending for further investigation. Herein, we review the current knowledge on APA and how its regulatory complex factors (CFI/IIm, CPSF, CSTF, and RBPs) work together to determine RNA splicing location, cell cycle velocity, microRNA processing, and oncogenesis regulation. We also discuss various APA experiment strategies and the future direction of APA research.
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37
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Culjkovic-Kraljacic B, Skrabanek L, Revuelta MV, Gasiorek J, Cowling VH, Cerchietti L, Borden KLB. The eukaryotic translation initiation factor eIF4E elevates steady-state m 7G capping of coding and noncoding transcripts. Proc Natl Acad Sci U S A 2020; 117:26773-26783. [PMID: 33055213 PMCID: PMC7604501 DOI: 10.1073/pnas.2002360117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Methyl-7-guanosine (m7G) "capping" of coding and some noncoding RNAs is critical for their maturation and subsequent activity. Here, we discovered that eukaryotic translation initiation factor 4E (eIF4E), itself a cap-binding protein, drives the expression of the capping machinery and increased capping efficiency of ∼100 coding and noncoding RNAs. To quantify this, we developed enzymatic (cap quantification; CapQ) and quantitative cap immunoprecipitation (CapIP) methods. The CapQ method has the further advantage that it captures information about capping status independent of the type of 5' cap, i.e., it is not restricted to informing on m7G caps. These methodological advances led to unanticipated revelations: 1) Many RNA populations are inefficiently capped at steady state (∼30 to 50%), and eIF4E overexpression increased this to ∼60 to 100%, depending on the RNA; 2) eIF4E physically associates with noncoding RNAs in the nucleus; and 3) approximately half of eIF4E-capping targets identified are noncoding RNAs. eIF4E's association with noncoding RNAs strongly positions it to act beyond translation. Coding and noncoding capping targets have activities that influence survival, cell morphology, and cell-to-cell interaction. Given that RNA export and translation machineries typically utilize capped RNA substrates, capping regulation provides means to titrate the protein-coding capacity of the transcriptome and, for noncoding RNAs, to regulate their activities. We also discovered a cap sensitivity element (CapSE) which conferred eIF4E-dependent capping sensitivity. Finally, we observed elevated capping for specific RNAs in high-eIF4E leukemia specimens, supporting a role for cap dysregulation in malignancy. In all, levels of capping RNAs can be regulated by eIF4E.
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Affiliation(s)
- Biljana Culjkovic-Kraljacic
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Lucy Skrabanek
- Applied Bioinformatics Core, Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065
| | - Maria V Revuelta
- Division of Hematology & Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY 10065
| | - Jadwiga Gasiorek
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Victoria H Cowling
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Leandro Cerchietti
- Division of Hematology & Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY 10065
| | - Katherine L B Borden
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC H3T 1J4, Canada;
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38
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CMTR1-Catalyzed 2'-O-Ribose Methylation Controls Neuronal Development by Regulating Camk2α Expression Independent of RIG-I Signaling. Cell Rep 2020; 33:108269. [PMID: 33086056 PMCID: PMC7574844 DOI: 10.1016/j.celrep.2020.108269] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 08/10/2020] [Accepted: 09/23/2020] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic mRNAs are 5′ end capped with a 7-methylguanosine, which is important for processing and translation of mRNAs. Cap methyltransferase 1 (CMTR1) catalyzes 2′-O-ribose methylation of the first transcribed nucleotide (N1 2′-O-Me) to mask mRNAs from innate immune surveillance by retinoic-acid-inducible gene-I (RIG-I). Nevertheless, whether this modification regulates gene expression for neuronal functions remains unexplored. Here, we find that knockdown of CMTR1 impairs dendrite development independent of secretory cytokines and RIG-I signaling. Using transcriptomic analyses, we identify altered gene expression related to dendrite morphogenesis instead of RIG-I-activated interferon signaling, such as decreased calcium/calmodulin-dependent protein kinase 2α (Camk2α). In line with these molecular changes, dendritic complexity in CMTR1-insufficient neurons is rescued by ectopic expression of CaMK2α but not by inactivation of RIG-I signaling. We further generate brain-specific CMTR1-knockout mice to validate these findings in vivo. Our study reveals the indispensable role of CMTR1-catalyzed N1 2′-O-Me in gene regulation for brain development. Every mRNA molecule in neurons is N1 2′-O methylated by CMTR1 CMTR1 is essential for neuromorphogenesis and brain development CMTR1 deficiency does not activate RIG-I and interferon signaling CMTR1 promotes Camk2α expression to support dendrite development
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39
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Doamekpor SK, Grudzien-Nogalska E, Mlynarska-Cieslak A, Kowalska J, Kiledjian M, Tong L. DXO/Rai1 enzymes remove 5'-end FAD and dephospho-CoA caps on RNAs. Nucleic Acids Res 2020; 48:6136-6148. [PMID: 32374864 PMCID: PMC7293010 DOI: 10.1093/nar/gkaa297] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 01/03/2023] Open
Abstract
In eukaryotes, the DXO/Rai1 enzymes can eliminate most of the incomplete and non-canonical NAD caps through their decapping, deNADding and pyrophosphohydrolase activities. Here, we report that these enzymes can also remove FAD and dephospho-CoA (dpCoA) non-canonical caps from RNA, and we have named these activities deFADding and deCoAping. The crystal structures of mammalian DXO with 3′-FADP or CoA and fission yeast Rai1 with 3′-FADP provide elegant insight to these activities. FAD and CoA are accommodated in the DXO/Rai1 active site by adopting folded conformations. The flavin of FAD and the pantetheine group of CoA contact the same region at the bottom of the active site tunnel, which undergoes conformational changes to accommodate the different cap moieties. We have developed FAD-capQ to detect and quantify FAD-capped RNAs and determined that FAD caps are present on short RNAs (with less than ∼200 nucleotides) in human cells and that these RNAs are stabilized in the absence of DXO.
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Affiliation(s)
- Selom K Doamekpor
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | | | - Agnieszka Mlynarska-Cieslak
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Joanna Kowalska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Megerditch Kiledjian
- Dept. Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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40
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Del Valle Morales D, Trotman JB, Bundschuh R, Schoenberg DR. Inhibition of cytoplasmic cap methylation identifies 5' TOP mRNAs as recapping targets and reveals recapping sites downstream of native 5' ends. Nucleic Acids Res 2020; 48:3806-3815. [PMID: 31996904 PMCID: PMC7144985 DOI: 10.1093/nar/gkaa046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 12/30/2019] [Accepted: 01/23/2020] [Indexed: 12/20/2022] Open
Abstract
Cap homeostasis is the cyclical process of decapping and recapping that maintains the translation and stability of a subset of the transcriptome. Previous work showed levels of some recapping targets decline following transient expression of an inactive form of RNMT (ΔN-RNMT), likely due to degradation of mRNAs with improperly methylated caps. The current study examined transcriptome-wide changes following inhibition of cytoplasmic cap methylation. This identified mRNAs with 5′-terminal oligopyrimidine (TOP) sequences as the largest single class of recapping targets. Cap end mapping of several TOP mRNAs identified recapping events at native 5′ ends and downstream of the TOP sequence of EIF3K and EIF3D. This provides the first direct evidence for downstream recapping. Inhibition of cytoplasmic cap methylation was also associated with mRNA abundance increases for a number of transcription, splicing, and 3′ processing factors. Previous work suggested a role for alternative polyadenylation in target selection, but this proved not to be the case. However, inhibition of cytoplasmic cap methylation resulted in a shift of upstream polyadenylation sites to annotated 3′ ends. Together, these results solidify cap homeostasis as a fundamental process of gene expression control and show cytoplasmic recapping can impact regulatory elements present at the ends of mRNA molecules.
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Affiliation(s)
- Daniel Del Valle Morales
- Center for RNA Biology, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, Columbus, OH 43210, USA.,Molecular, Cellular and Developmental Biology Program, Columbus, OH 43210, USA
| | - Jackson B Trotman
- Center for RNA Biology, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, Columbus, OH 43210, USA
| | - Ralf Bundschuh
- Center for RNA Biology, Columbus, OH 43210, USA.,Department of Physics, Columbus, OH 43210, USA.,Department of Chemistry and Biochemistry, Columbus, OH 43210, USA.,Division of Hematology, The Ohio State University, Columbus, OH 43210, USA
| | - Daniel R Schoenberg
- Center for RNA Biology, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, Columbus, OH 43210, USA
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41
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Pan S, Li KE, Huang W, Zhong H, Wu H, Wang Y, Zhang H, Cai Z, Guo H, Chen X, Xia Y. Arabidopsis DXO1 possesses deNADding and exonuclease activities and its mutation affects defense-related and photosynthetic gene expression. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:967-983. [PMID: 31449356 PMCID: PMC8034840 DOI: 10.1111/jipb.12867] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 08/23/2019] [Indexed: 05/26/2023]
Abstract
RNA capping and decapping tightly coordinate with transcription, translation, and RNA decay to regulate gene expression. Proteins in the DXO/Rai1 family have been implicated in mRNA decapping and decay, and mammalian DXO was recently found to also function as a decapping enzyme for NAD+ -capped RNAs (NAD-RNA). The Arabidopsis genome contains a single gene encoding a DXO/Rai1 protein, AtDXO1. Here we show that AtDXO1 possesses both NAD-RNA decapping activity and 5'-3' exonuclease activity but does not hydrolyze the m7 G cap. The atdxo1 mutation increased the stability of NAD-RNAs and led to pleiotropic phenotypes, including severe growth retardation, pale color, and multiple developmental defects. Transcriptome profiling analysis showed that the atdxo1 mutation resulted in upregulation of defense-related genes but downregulation of photosynthesis-related genes. The autoimmunity phenotype of the mutant could be suppressed by either eds1 or npr1 mutation. However, the various phenotypes associated with the atdxo1 mutant could be complemented by an enzymatically inactive AtDXO1. The atdxo1 mutation apparently enhances post-transcriptional gene silencing by elevating levels of siRNAs. Our study indicates that AtDXO1 regulates gene expression in various biological and physiological processes through its pleiotropic molecular functions in mediating RNA processing and decay.
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Affiliation(s)
- Shuying Pan
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Kai-en Li
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Wei Huang
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Huan Zhong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Huihui Wu
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuan Wang
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, California 92521, USA
| | - He Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Hongwei Guo
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xuemei Chen
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, California 92521, USA
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
- State Key Laboratory of Agricultural Biotechnology, School of Life Sciences, Chinese University of Hong Kong, Hong Kong, China
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42
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Höfler S, Carlomagno T. Structural and functional roles of 2'-O-ribose methylations and their enzymatic machinery across multiple classes of RNAs. Curr Opin Struct Biol 2020; 65:42-50. [PMID: 32610226 DOI: 10.1016/j.sbi.2020.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/14/2020] [Accepted: 05/20/2020] [Indexed: 01/27/2023]
Abstract
RNA complexity is augmented by numerous post-transcriptional modifications, which influence RNA function by modulating its structure and interactome. One prominent modification is methylation at the ribose 2'-hydroxyl group. 2'-O-methylation has been found in all RNA classes, with rRNA and tRNA being extensively modified. The exact function of 2'-O-methylation at specific RNA sites is still not understood, with a few notable exceptions. The relevance of 2'-O-methylation for cell survival and well-being is proven by the large effort that the cell spends in maintaining a diverse and highly regulated methylation machinery. Here, we review the current knowledge on the impact of 2'-O-methylation on structure and function of different RNAs as well as on the factors determining substrate specificity in the enzymatic machinery.
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Affiliation(s)
- Simone Höfler
- Biomolekulares Wirkstoffzentrum, Leibniz Universität Hannover, Schneiderberg 38, 30167 Hannover, Germany
| | - Teresa Carlomagno
- Biomolekulares Wirkstoffzentrum, Leibniz Universität Hannover, Schneiderberg 38, 30167 Hannover, Germany; Helmholz Zentrum für Infektionsforschung, Inhoffenstraße 7, 38124 Braunschweig, Germany.
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43
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Luo Y, Schofield JA, Simon MD, Slavoff SA. Global Profiling of Cellular Substrates of Human Dcp2. Biochemistry 2020; 59:4176-4188. [PMID: 32365300 DOI: 10.1021/acs.biochem.0c00069] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Decapping is the first committed step in 5'-to-3' RNA decay, and in the cytoplasm of human cells, multiple decapping enzymes regulate the stabilities of distinct subsets of cellular transcripts. However, the complete set of RNAs regulated by any individual decapping enzyme remains incompletely mapped, and no consensus sequence or property is currently known to unambiguously predict decapping enzyme substrates. Dcp2 was the first-identified and best-studied eukaryotic decapping enzyme, but it has been shown to regulate the stability of <400 transcripts in mammalian cells to date. Here, we globally profile changes in the stability of the human transcriptome in Dcp2 knockout cells via TimeLapse-seq. We find that P-body enrichment is the strongest correlate of Dcp2-dependent decay and that modification with m6A exhibits an additive effect with P-body enrichment for Dcp2 targeting. These results are consistent with a model in which P-bodies represent sites where translationally repressed transcripts are sorted for decay by soluble cytoplasmic decay complexes through additional molecular marks.
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Affiliation(s)
- Yang Luo
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Jeremy A Schofield
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06529, United States
| | - Matthew D Simon
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06529, United States
| | - Sarah A Slavoff
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06529, United States
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44
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Williams GD, Gokhale NS, Snider DL, Horner SM. The mRNA Cap 2'- O-Methyltransferase CMTR1 Regulates the Expression of Certain Interferon-Stimulated Genes. mSphere 2020; 5:e00202-20. [PMID: 32404510 PMCID: PMC7227766 DOI: 10.1128/msphere.00202-20] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/29/2020] [Indexed: 02/06/2023] Open
Abstract
Type I interferons (IFN) initiate an antiviral state through a signal transduction cascade that leads to the induction of hundreds of IFN-stimulated genes (ISGs) to restrict viral infection. Recently, RNA modifications on both host and viral RNAs have been described as regulators of infection. However, the impact of host mRNA cap modifications on the IFN response and how this regulates viral infection are unknown. Here, we reveal that CMTR1, an ISG that catalyzes 2'-O-methylation of the first transcribed nucleotide in cellular mRNA (Cap 1), promotes the protein expression of specific ISGs that contribute to the antiviral response. Depletion of CMTR1 reduces the IFN-induced protein levels of ISG15, MX1, and IFITM1, without affecting their transcript abundance. However, CMTR1 depletion does not significantly affect the IFN-induced protein or transcript abundance of IFIT1 and IFIT3. Importantly, knockdown of IFIT1, which acts with IFIT3 to inhibit the translation of RNAs lacking Cap 1 2'-O-methylation, restores protein expression of ISG15, MX1, and IFITM1 in cells depleted of CMTR1. Finally, we found that CMTR1 plays a role in restricting RNA virus replication, likely by ensuring the expression of specific antiviral ISGs. Taken together, these data reveal that CMTR1 is required to establish an antiviral state by ensuring the protein expression of a subset of ISGs during the type I IFN response.IMPORTANCE Induction of an efficient type I IFN response is important to control viral infection. We show that the host 2'-O-methyltransferase CMTR1 facilitates the protein expression of ISGs in human cells by preventing IFIT1 from inhibiting the translation of those mRNAs lacking cap 2'-O-methylation. Thus, CMTR1 promotes the IFN-mediated antiviral response.
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Affiliation(s)
- Graham D Williams
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Nandan S Gokhale
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Daltry L Snider
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Stacy M Horner
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
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45
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A Novel NAD-RNA Decapping Pathway Discovered by Synthetic Light-Up NAD-RNAs. Biomolecules 2020; 10:biom10040513. [PMID: 32231086 PMCID: PMC7226252 DOI: 10.3390/biom10040513] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 12/20/2022] Open
Abstract
The complexity of the transcriptome is governed by the intricate interplay of transcription, RNA processing, translocation, and decay. In eukaryotes, the removal of the 5’-RNA cap is essential for the initiation of RNA degradation. In addition to the canonical 5’-N7-methyl guanosine cap in eukaryotes, the ubiquitous redox cofactor nicotinamide adenine dinucleotide (NAD) was identified as a new 5’-RNA cap structure in prokaryotic and eukaryotic organisms. So far, two classes of NAD-RNA decapping enzymes have been identified, namely Nudix enzymes that liberate nicotinamide mononucleotide (NMN) and DXO-enzymes that remove the entire NAD cap. Herein, we introduce 8-(furan-2-yl)-substituted NAD-capped-RNA (FurNAD-RNA) as a new research tool for the identification and characterization of novel NAD-RNA decapping enzymes. These compounds are found to be suitable for various enzymatic reactions that result in the release of a fluorescence quencher, either nicotinamide (NAM) or nicotinamide mononucleotide (NMN), from the RNA which causes a fluorescence turn-on. FurNAD-RNAs allow for real-time quantification of decapping activity, parallelization, high-throughput screening and identification of novel decapping enzymes in vitro. Using FurNAD-RNAs, we discovered that the eukaryotic glycohydrolase CD38 processes NAD-capped RNA in vitro into ADP-ribose-modified-RNA and nicotinamide and therefore might act as a decapping enzyme in vivo. The existence of multiple pathways suggests that the decapping of NAD-RNA is an important and regulated process in eukaryotes.
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46
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Doamekpor SK, Gozdek A, Kwasnik A, Kufel J, Tong L. A novel 5'-hydroxyl dinucleotide hydrolase activity for the DXO/Rai1 family of enzymes. Nucleic Acids Res 2020; 48:349-358. [PMID: 31777937 PMCID: PMC6943137 DOI: 10.1093/nar/gkz1107] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/01/2019] [Accepted: 11/13/2019] [Indexed: 12/16/2022] Open
Abstract
Modifications at the 5'-end of RNAs play a pivotal role in determining their fate. In eukaryotes, the DXO/Rai1 family of enzymes removes numerous 5'-end RNA modifications, thereby regulating RNA turnover. Mouse DXO catalyzes the elimination of incomplete 5'-end caps (including pyrophosphate) and the non-canonical NAD+ cap on mRNAs, and possesses distributive 5'-3' exoribonuclease activity toward 5'-monophosphate (5'-PO4) RNA. Here, we demonstrate that DXO also catalyzes the hydrolysis of RNAs bearing a 5'-hydroxyl group (5'-OH RNA). The crystal structure of DXO in complex with a 5'-OH RNA substrate mimic at 2.0 Å resolution provides elegant insight into the molecular mechanism of this activity. More importantly, the structure predicts that DXO first removes a dinucleotide from 5'-OH RNA. Our nuclease assays confirm this prediction and demonstrate that this 5'-hydroxyl dinucleotide hydrolase (HDH) activity for DXO is higher than the subsequent 5'-3' exoribonuclease activity for selected substrates. Fission yeast Rai1 also has HDH activity although it does not have 5'-3' exonuclease activity, and the Rat1-Rai1 complex can completely degrade 5'-OH RNA. An Arabidopsis DXO1 variant is active toward 5'-OH RNA but prefers 5'-PO4 RNA. Collectively, these studies demonstrate the diverse activities of DXO/Rai1 and expands the collection of RNA substrates that can undergo 5'-3' mediated decay.
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Affiliation(s)
- Selom K Doamekpor
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Agnieszka Gozdek
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Aleksandra Kwasnik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Joanna Kufel
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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47
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Dendooven T, Luisi BF, Bandyra KJ. RNA lifetime control, from stereochemistry to gene expression. Curr Opin Struct Biol 2019; 61:59-70. [PMID: 31869589 DOI: 10.1016/j.sbi.2019.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/13/2019] [Accepted: 10/14/2019] [Indexed: 10/25/2022]
Abstract
Through the activities of various multi-component assemblies, protein-coding transcripts can be chaperoned toward protein synthesis or nudged into a funnel of rapid destruction. The capacity of these machine-like assemblies to tune RNA lifetime underpins the harmony of gene expression in all cells. Some of the molecular machines that mediate transcript turnover also contribute to on-the-fly surveillance of aberrant mRNAs and non-coding RNAs. How these dynamic assemblies distinguish functional RNAs from those that must be degraded is an intriguing puzzle for understanding the regulation of gene expression and dysfunction associated with disease. Recent data illuminate what the machines look like, and how they find, recognise and operate on transcripts to sculpt the dynamic regulatory landscape. This review captures current structural and mechanistic insights into the key enzymes and their effector assemblies that contribute to the fate-determining decision points for RNA in post-transcriptional control of genetic information.
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Affiliation(s)
- Tom Dendooven
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.
| | - Katarzyna J Bandyra
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.
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48
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Wang J, Alvin Chew BL, Lai Y, Dong H, Xu L, Balamkundu S, Cai WM, Cui L, Liu CF, Fu XY, Lin Z, Shi PY, Lu TK, Luo D, Jaffrey SR, Dedon PC. Quantifying the RNA cap epitranscriptome reveals novel caps in cellular and viral RNA. Nucleic Acids Res 2019; 47:e130. [PMID: 31504804 PMCID: PMC6847653 DOI: 10.1093/nar/gkz751] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 07/16/2019] [Accepted: 08/23/2019] [Indexed: 12/13/2022] Open
Abstract
Chemical modification of transcripts with 5' caps occurs in all organisms. Here, we report a systems-level mass spectrometry-based technique, CapQuant, for quantitative analysis of an organism's cap epitranscriptome. The method was piloted with 21 canonical caps-m7GpppN, m7GpppNm, GpppN, GpppNm, and m2,2,7GpppG-and 5 'metabolite' caps-NAD, FAD, UDP-Glc, UDP-GlcNAc, and dpCoA. Applying CapQuant to RNA from purified dengue virus, Escherichia coli, yeast, mouse tissues, and human cells, we discovered new cap structures in humans and mice (FAD, UDP-Glc, UDP-GlcNAc, and m7Gpppm6A), cell- and tissue-specific variations in cap methylation, and high proportions of caps lacking 2'-O-methylation (m7Gpppm6A in mammals, m7GpppA in dengue virus). While substantial Dimroth-induced loss of m1A and m1Am arose with specific RNA processing conditions, human lymphoblast cells showed no detectable m1A or m1Am in caps. CapQuant accurately captured the preference for purine nucleotides at eukaryotic transcription start sites and the correlation between metabolite levels and metabolite caps.
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Affiliation(s)
- Jin Wang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, Inner Mongolia University, Hohhot, People's Republic of China
- School of Life Sciences, Inner Mongolia University, Hohhot, People's Republic of China
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
| | - Bing Liang Alvin Chew
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
- NTU Institute of Health Technologies, Interdisciplinary Graduate Programme, Nanyang Technological University, Singapore
| | - Yong Lai
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
| | - Hongping Dong
- Shanghai Blueray Biopharma, Shanghai, People's Republic of China
| | - Luang Xu
- Cancer Science Institute of Singapore, Singapore
| | - Seetharamsingh Balamkundu
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Weiling Maggie Cai
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
- Department of Microbiology, National University of Singapore, Singapore
| | - Liang Cui
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
| | - Chuan Fa Liu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Xin-Yuan Fu
- Cancer Science Institute of Singapore, Singapore
| | - Zhenguo Lin
- Department of Biology, Saint Louis University, St. Louis, MO, USA
| | - Pei-Yong Shi
- Departments of Biochemistry & Molecular Biology and Pharmacology & Toxicology, and Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Timothy K Lu
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
- Synthetic Biology Center, Departments of Biological Engineering and Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Medical College, Cornell University, New York, NY, USA
| | - Peter C Dedon
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore
- Dept. of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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49
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Abstract
The numerous quality control pathways that target defective ribonucleic acids (RNAs) for degradation play key roles in shaping mammalian transcriptomes and preventing disease. These pathways monitor most steps in the biogenesis of both noncoding RNAs (ncRNAs) and protein-coding messenger RNAs (mRNAs), degrading ncRNAs that fail to form functional complexes with one or more proteins and eliminating mRNAs that encode abnormal, potentially toxic proteins. Mutations in components of diverse RNA surveillance pathways manifest as disease. Some mutations are characterized by increased interferon production, suggesting that a major role of these pathways is to prevent aberrant cellular RNAs from being recognized as "non-self." Other mutations are common in cancer, or result in developmental defects, revealing the importance of RNA surveillance to cell and organismal function.
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Affiliation(s)
- Sandra L Wolin
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.
- Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
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50
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Garland W, Jensen TH. Nuclear sorting of RNA. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 11:e1572. [PMID: 31713323 DOI: 10.1002/wrna.1572] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/30/2019] [Accepted: 10/08/2019] [Indexed: 12/27/2022]
Abstract
The majority of the mammalian genome is transcribed by RNA polymerase II, yielding a vast amount of noncoding RNA (ncRNA) in addition to the standard production of mRNA. The typical nuclear biogenesis of mRNA relies on the tightly controlled coupling of co- and post-transcriptional processing events, which ultimately results in the export of transcripts into the cytoplasm. These processes are subject to surveillance by nuclear RNA decay pathways to prevent the export of aberrant, or otherwise "non-optimal," transcripts. However, unlike mRNA, many long ncRNAs are nuclear retained and those that maintain enduring functions must employ precautions to evade decay. Proper sorting and localization of RNA is therefore an essential activity in eukaryotic cells and the formation of ribonucleoprotein complexes during early stages of RNA synthesis is central to deciding such transcript fate. This review details our current understanding of the pathways and factors that direct RNAs towards a particular destiny and how transcripts combat the adverse conditions of the nucleus. This article is categorized under: RNA Export and Localization > Nuclear Export/Import RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- William Garland
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C., Denmark
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C., Denmark
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