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McClary-Gutierrez JS, Aanderud ZT, Al-Faliti M, Duvallet C, Gonzalez R, Guzman J, Holm RH, Jahne MA, Kantor RS, Katsivelis P, Kuhn KG, Langan LM, Mansfeldt C, McLellan SL, Grijalva LMM, Murnane KS, Naughton CC, Packman AI, Paraskevopoulos S, Radniecki TS, Roman FA, Shrestha A, Stadler LB, Steele JA, Swalla BM, Vikesland P, Wartell B, Wilusz CJ, Wong JCC, Boehm AB, Halden RU, Bibby K, Vela JD. Standardizing data reporting in the research community to enhance the utility of open data for SARS-CoV-2 wastewater surveillance. Environ Sci (Camb) 2021; 9:10.1039/d1ew00235j. [PMID: 34567579 PMCID: PMC8459677 DOI: 10.1039/d1ew00235j] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
SARS-CoV-2 RNA detection in wastewater is being rapidly developed and adopted as a public health monitoring tool worldwide. With wastewater surveillance programs being implemented across many different scales and by many different stakeholders, it is critical that data collected and shared are accompanied by an appropriate minimal amount of metainformation to enable meaningful interpretation and use of this new information source and intercomparison across datasets. While some databases are being developed for specific surveillance programs locally, regionally, nationally, and internationally, common globally-adopted data standards have not yet been established within the research community. Establishing such standards will require national and international consensus on what metainformation should accompany SARS-CoV-2 wastewater measurements. To establish a recommendation on minimum information to accompany reporting of SARS-CoV-2 occurrence in wastewater for the research community, the United States National Science Foundation (NSF) Research Coordination Network on Wastewater Surveillance for SARS-CoV-2 hosted a workshop in February 2021 with participants from academia, government agencies, private companies, wastewater utilities, public health laboratories, and research institutes. This report presents the primary two outcomes of the workshop: (i) a recommendation on the set of minimum meta-information that is needed to confidently interpret wastewater SARS-CoV-2 data, and (ii) insights from workshop discussions on how to improve standardization of data reporting.
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Affiliation(s)
- Jill S McClary-Gutierrez
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Zachary T Aanderud
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, USA
| | - Mitham Al-Faliti
- Department of Civil and Environmental Engineering, Howard University, Washington, DC, USA
| | | | - Raul Gonzalez
- Hampton Roads Sanitation District, Virginia Beach, VA, USA
| | - Joe Guzman
- Orange County Public Health Laboratory, Newport Beach, CA, USA
| | - Rochelle H Holm
- Christina Lee Brown Envirome Institute, University of Louisville, 302 E. Muhammad Ali Blvd., Louisville, KY, 40202, USA
| | | | - Rose S Kantor
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA
| | | | - Katrin Gaardbo Kuhn
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Laura M Langan
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, USA
| | - Cresten Mansfeldt
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Sandra L McLellan
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | | | - Kevin S Murnane
- Department of Pharmacology, Toxicology & Neuroscience, Louisiana State University Health - Shreveport, Shreveport, LA, USA
- Department of Psychiatry, Louisiana State University Health - Shreveport, Shreveport, LA, USA
- Louisiana Addiction Research Center, Louisiana State University Health - Shreveport, Shreveport, LA, USA
| | - Colleen C Naughton
- Civil and Environmental Engineering, University of California, Merced, CA, USA
| | - Aaron I Packman
- Department of Civil and Environmental Engineering, Northwestern Center for Water Research, Northwestern University, Evanston, IL, USA
| | | | - Tyler S Radniecki
- School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR, USA
| | - Fernando A Roman
- Civil and Environmental Engineering, University of California, Merced, CA, USA
| | - Abhilasha Shrestha
- Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois Chicago, Chicago, IL, USA
| | - Lauren B Stadler
- Department of Civil & Environmental Engineering, Rice University, Houston, TX, USA
| | - Joshua A Steele
- Southern California Coastal Water Research Project, Costa Mesa, CA, USA
| | | | - Peter Vikesland
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Brian Wartell
- Department of Environmental Engineering, University of Maryland, Baltimore, MD, USA
| | - Carol J Wilusz
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | | | - Alexandria B Boehm
- Department of Civil & Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Rolf U Halden
- Biodesign Center for Environmental Health Engineering, Biodesign Institute, Arizona State University, Tempe, AZ, USA
- OneWaterOneHealth, Arizona State University Foundation, Tempe, AZ, USA
- AquaVitas, LLC, Scottsdale, AZ, USA
| | - Kyle Bibby
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Jeseth Delgado Vela
- Department of Civil and Environmental Engineering, Howard University, Washington, DC, USA
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Heck AM, Russo J, Wilusz J, Nishimura EO, Wilusz CJ. YTHDF2 destabilizes m 6A-modified neural-specific RNAs to restrain differentiation in induced pluripotent stem cells. RNA 2020; 26:739-755. [PMID: 32169943 PMCID: PMC7266156 DOI: 10.1261/rna.073502.119] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 03/12/2020] [Indexed: 06/10/2023]
Abstract
N6-methyladenosine (m6A) is an abundant post-transcriptional modification that can impact RNA fate via interactions with m6A-specific RNA binding proteins. Despite accumulating evidence that m6A plays an important role in modulating pluripotency, the influence of m6A reader proteins in pluripotency is less clear. Here, we report that YTHDF2, an m6A reader associated with mRNA degradation, is highly expressed in induced pluripotent stem cells (iPSCs) and down-regulated during neural differentiation. Through RNA sequencing, we identified a group of m6A-modified transcripts associated with neural development that are directly regulated by YTDHF2. Depletion of YTHDF2 in iPSCs leads to stabilization of these transcripts, loss of pluripotency, and induction of neural-specific gene expression. Collectively, our results suggest YTHDF2 functions to restrain expression of neural-specific mRNAs in iPSCs and facilitate their rapid and coordinated up-regulation during neural induction. These effects are both achieved by destabilization of the targeted transcripts.
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Affiliation(s)
- Adam M Heck
- Program in Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
- Department of Microbiology, Immunology & Pathology
| | - Joseph Russo
- Department of Microbiology, Immunology & Pathology
| | - Jeffrey Wilusz
- Program in Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
- Department of Microbiology, Immunology & Pathology
| | - Erin Osborne Nishimura
- Program in Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Carol J Wilusz
- Program in Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
- Department of Microbiology, Immunology & Pathology
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3
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Heck AM, Wilusz CJ. Small changes, big implications: The impact of m 6A RNA methylation on gene expression in pluripotency and development. Biochim Biophys Acta Gene Regul Mech 2019; 1862:194402. [PMID: 31325527 PMCID: PMC6742438 DOI: 10.1016/j.bbagrm.2019.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/21/2019] [Accepted: 07/12/2019] [Indexed: 12/20/2022]
Abstract
In order to maintain a state of self-renewal, yet retain the ability to rapidly differentiate in response to external signals, pluripotent cells exert tight control over gene expression at many levels. Recent studies have suggested that N6-methyladenosine (m6A) RNA methylation, one of the most abundant post-transcriptional modifications, is important for both pluripotency and differentiation. In this review, we summarize the current state of the m6A field, with emphasis on the impact of writers, erasers and readers of m6A on RNA metabolism and stem cell biology.
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Affiliation(s)
- Adam M Heck
- Program in Cell & Molecular Biology, and Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80525, United States of America
| | - Carol J Wilusz
- Program in Cell & Molecular Biology, and Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80525, United States of America.
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4
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Upadhyay R, Sanchez-Hidalgo A, Wilusz CJ, Lenaerts AJ, Arab J, Yeh J, Stefanisko K, Tarasova NI, Gonzalez-Juarrero M. Host Directed Therapy for Chronic Tuberculosis via Intrapulmonary Delivery of Aerosolized Peptide Inhibitors Targeting the IL-10-STAT3 Pathway. Sci Rep 2018; 8:16610. [PMID: 30413750 PMCID: PMC6226451 DOI: 10.1038/s41598-018-35023-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/30/2018] [Indexed: 12/17/2022] Open
Abstract
Here we demonstrate that aerosols of host directed therapies [HDT] administered during a chronic Mycobacterium tuberculosis (Mtb) infection have bactericidal effect. The pulmonary bacterial load of C57BL/6 mice chronically infected with Mtb was reduced by 1.7 and 0.6 log10CFU after two weeks of treatment via aerosol delivery with ST3-H2A2, [a selective peptide inhibitor of the STAT3 N-terminal domain] or IL10R1-7 [selective peptide inhibitor for the IL-10Ra] respectively and when compared to control mice treated with IL10R1-14 [peptide inhibitor used as negative control] or untreated mice infected with Mtb. Accordingly, when compared to control mice, the bactericidal capacity in mice was enhanced upon treatment with peptide inhibitors ST3-H2A2 and IL10R1-7 as evidenced by higher pulmonary activities of nitric oxide synthase, NADPH oxidase and lysozyme enzymes and decreased arginase enzyme activity. This therapy also modulated important checkpoints [Bcl2, Beclin-1, Atg 5, bax] in the apoptosis-autophagy pathways. Thus, even in the absence of antibiotics, targeting of the host pulmonary IL-10-STAT3 pathway can significantly reduce the Mtb bacilli load in the lungs, modulate the host own bactericidal capacity and apoptosis and autophagy pathways. Our approach here also allows targeting checkpoints of the lungs to determine their specific contribution in pulmonary immunity or pathogenesis.
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Affiliation(s)
- Rashmi Upadhyay
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Andrea Sanchez-Hidalgo
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Anne J Lenaerts
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Jennifer Arab
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Joanna Yeh
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Karen Stefanisko
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Nadya I Tarasova
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Mercedes Gonzalez-Juarrero
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA.
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Charley PA, Wilusz CJ, Wilusz J. Identification of phlebovirus and arenavirus RNA sequences that stall and repress the exoribonuclease XRN1. J Biol Chem 2017; 293:285-295. [PMID: 29118186 DOI: 10.1074/jbc.m117.805796] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/06/2017] [Indexed: 12/22/2022] Open
Abstract
Regulated mRNA decay plays a vital role in determining both the level and quality of cellular gene expression. Viral RNAs must successfully evade this host RNA decay machinery to establish a productive infection. One way for RNA viruses to accomplish this is to target the cellular exoribonuclease XRN1, because this enzyme is accessible in the cytoplasm and plays a major role in mRNA decay. Members of the Flaviviridae use RNA structures in their 5'- or 3'-untranslated regions to stall and repress XRN1, effectively stabilizing viral RNAs while also causing significant dysregulation of host cell mRNA stability. Here, we use a series of biochemical assays to demonstrate that the 3'-terminal portion of the nucleocapsid (N) mRNA of Rift Valley fever virus, a phlebovirus of the Bunyaviridae family, also can effectively stall and repress XRN1. The region responsible for impeding XRN1 includes a G-rich portion that likely forms a G-quadruplex structure. The 3'-terminal portions of ambisense-derived transcripts of multiple arenaviruses also stalled XRN1. Therefore, we conclude that RNAs from two additional families of mammalian RNA viruses stall and repress XRN1. This observation. emphasizes the importance and commonality of this viral strategy to interfere with the 5'-to-3'-exoribonuclease component of the cytoplasmic RNA decay machinery.
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Affiliation(s)
- Phillida A Charley
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523
| | - Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523.
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Russo J, Lee JE, López CM, Anderson J, Nguyen TMP, Heck AM, Wilusz J, Wilusz CJ. The CELF1 RNA-Binding Protein Regulates Decay of Signal Recognition Particle mRNAs and Limits Secretion in Mouse Myoblasts. PLoS One 2017; 12:e0170680. [PMID: 28129347 PMCID: PMC5271678 DOI: 10.1371/journal.pone.0170680] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/09/2017] [Indexed: 02/06/2023] Open
Abstract
We previously identified several mRNAs encoding components of the secretory pathway, including signal recognition particle (SRP) subunit mRNAs, among transcripts associated with the RNA-binding protein CELF1. Through immunoprecipitation of RNAs crosslinked to CELF1 in myoblasts and in vitro binding assays using recombinant CELF1, we now provide evidence that CELF1 directly binds the mRNAs encoding each of the subunits of the SRP. Furthermore, we determined the half-lives of the Srp transcripts in control and CELF1 knockdown myoblasts. Our results indicate CELF1 is a destabilizer of at least five of the six Srp transcripts and that the relative abundance of the SRP proteins is out of balance when CELF1 is depleted. CELF1 knockdown myoblasts exhibit altered secretion of a luciferase reporter protein and are impaired in their ability to migrate and close a wound, consistent with a defect in the secreted extracellular matrix. Importantly, similar defects in wound healing are observed when SRP subunit imbalance is induced by over-expression of SRP68. Our studies support the existence of an RNA regulon containing Srp mRNAs that is controlled by CELF1. One implication is that altered function of CELF1 in myotonic dystrophy may contribute to changes in the extracellular matrix of affected muscle through defects in secretion.
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Affiliation(s)
- Joseph Russo
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jerome E. Lee
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Carolina M. López
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - John Anderson
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Thuy-mi P. Nguyen
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Adam M. Heck
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Carol J. Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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7
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Moon SL, Dodd BJT, Brackney DE, Wilusz CJ, Ebel GD, Wilusz J. Flavivirus sfRNA suppresses antiviral RNA interference in cultured cells and mosquitoes and directly interacts with the RNAi machinery. Virology 2015; 485:322-9. [PMID: 26331679 DOI: 10.1016/j.virol.2015.08.009] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 08/07/2015] [Accepted: 08/09/2015] [Indexed: 10/23/2022]
Abstract
Productive arbovirus infections require mechanisms to suppress or circumvent the cellular RNA interference (RNAi) pathway, a major antiviral response in mosquitoes. In this study, we demonstrate that two flaviviruses, Dengue virus and Kunjin virus, significantly repress siRNA-mediated RNAi in infected human cells as well as during infection of the mosquito vector Culex quinquefasciatus. Arthropod-borne flaviviruses generate a small structured non-coding RNA from the viral 3' UTR referred to as sfRNA. Analysis of infections with a mutant Kunjin virus that is unable to generate appreciable amounts of the major sfRNA species indicated that RNAi suppression was associated with the generation of the non-coding sfRNA. Co-immunoprecipitation of sfRNA with RNAi mediators Dicer and Ago2 suggest a model for RNAi suppression. Collectively, these data help to establish a clear role for sfRNA in RNAi suppression and adds to the emerging impact of viral long non-coding RNAs in modulating aspects of anti-viral immune processes.
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Affiliation(s)
- Stephanie L Moon
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Benjamin J T Dodd
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Doug E Brackney
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Gregory D Ebel
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
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8
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Moon SL, Blackinton JG, Anderson JR, Dozier MK, Dodd BJT, Keene JD, Wilusz CJ, Bradrick SS, Wilusz J. XRN1 stalling in the 5' UTR of Hepatitis C virus and Bovine Viral Diarrhea virus is associated with dysregulated host mRNA stability. PLoS Pathog 2015; 11:e1004708. [PMID: 25747802 PMCID: PMC4352041 DOI: 10.1371/journal.ppat.1004708] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 01/26/2015] [Indexed: 01/11/2023] Open
Abstract
We demonstrate that both Hepatitis C virus (HCV) and Bovine Viral Diarrhea virus (BVDV) contain regions in their 5’ UTRs that stall and repress the enzymatic activity of the cellular 5’-3’ exoribonuclease XRN1, resulting in dramatic changes in the stability of cellular mRNAs. We used biochemical assays, virus infections, and transfection of the HCV and BVDV 5’ untranslated regions in the absence of other viral gene products to directly demonstrate the existence and mechanism of this novel host-virus interaction. In the context of HCV infection, we observed globally increased stability of mRNAs resulting in significant increases in abundance of normally short-lived mRNAs encoding a variety of relevant oncogenes and angiogenesis factors. These findings suggest that non-coding regions from multiple genera of the Flaviviridae interfere with XRN1 and impact post-transcriptional processes, causing global dysregulation of cellular gene expression which may promote cell growth and pathogenesis. Understanding how a persistent virus like Hepatitis C Virus (HCV) interfaces with the cellular machinery during infection can provide significant insights into mechanisms of pathogenesis. We demonstrate that while trying to degrade HCV transcripts, a major cellular exonuclease called XRN1 stalls and gets repressed in the 5’ noncoding region of the viral mRNA. Interestingly, the region where XRN1 stalls in the 5’ UTR includes the viral IRES that is required for translation initiation, uncovering a novel, unexpected function for this well-studied region. Differential mRNA stability is a major regulator of gene expression in cells. Curiously, repression of the cellular XRN1 exonuclease is associated with a general repression of mRNA decay in general in HCV-infected cells. Thus numerous cellular mRNAs are stabilized and accumulate in a dysregulated fashion during HCV infection. Normally short-lived mRNAs are disproportionately affected—including mRNAs that encode immune regulators and oncogenes. Thus, this study suggests a novel role for the 5’ UTR of HCV in molecular pathogenesis—including hepatocellular carcinoma. Furthermore, the 5’ UTR of Bovine Viral Diarrhea virus also represses the XRN1 enzyme and stabilizes cellular mRNA. Therefore a strategy of 5’ UTR-mediated XRN1 repression appears to be conserved among the vector-independent members of the Flaviviridae.
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Affiliation(s)
- Stephanie L. Moon
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jeffrey G. Blackinton
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - John R. Anderson
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Mary K. Dozier
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Benjamin J. T. Dodd
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jack D. Keene
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Carol J. Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Shelton S. Bradrick
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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9
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Barnhart MD, Moon SL, Emch AW, Wilusz CJ, Wilusz J. Changes in cellular mRNA stability, splicing, and polyadenylation through HuR protein sequestration by a cytoplasmic RNA virus. Cell Rep 2013; 5:909-17. [PMID: 24210824 PMCID: PMC3849337 DOI: 10.1016/j.celrep.2013.10.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/13/2013] [Accepted: 10/07/2013] [Indexed: 12/12/2022] Open
Abstract
The impact of RNA viruses on the posttranscriptional regulation of cellular gene expression is unclear. Sindbis virus causes a dramatic relocalization of the cellular HuR protein from the nucleus to the cytoplasm in infected cells. This is to the result of the expression of large amounts of viral RNAs that contain high-affinity HuR binding sites in their 3' UTRs effectively serving as a sponge for the HuR protein. Sequestration of HuR by Sindbis virus is associated with destabilization of cellular mRNAs that normally bind HuR and rely on it to regulate their expression. Furthermore, significant changes can be observed in nuclear alternative polyadenylation and splicing events on cellular pre-mRNAs as a result of sequestration of HuR protein by the 3' UTR of transcripts of this cytoplasmic RNA virus. These studies suggest a molecular mechanism of virus-host interaction that probably has a significant impact on virus replication, cytopathology, and pathogenesis.
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Affiliation(s)
| | | | - Alexander W. Emch
- Cell and Molecular Biology Program, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80525
| | - Carol J. Wilusz
- Cell and Molecular Biology Program, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80525
| | - Jeffrey Wilusz
- Cell and Molecular Biology Program, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80525
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10
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Abstract
The bacterial Hfq protein is a versatile modulator of RNA function and is particularly important for regulation mediated by small non-coding RNAs. Hfq is a bacterial Sm protein but bears more similarity to the eukaryotic Sm-like (Lsm) family of proteins than the prototypical Sm proteins. Hfq and Lsm proteins share the ability to chaperone RNA-RNA and RNA/protein interactions and an interesting penchant for protecting the 3′ end of a transcript from exonucleolytic decay while encouraging degradation through other pathways. Our view of Lsm function in eukaryotes has historically been informed by studies of Hfq structure and function but mutational analyses and structural studies of Lsm sub-complexes have given important insights as well. Here, we aim to compare and contrast the roles of these evolutionarily related complexes and to highlight areas for future investigation.
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO, USA.
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11
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Talwar S, Balasubramanian S, Sundaramurthy S, House R, Wilusz CJ, Kuppuswamy D, D'Silva N, Gillespie MB, Hill EG, Palanisamy V. Overexpression of RNA-binding protein CELF1 prevents apoptosis and destabilizes pro-apoptotic mRNAs in oral cancer cells. RNA Biol 2013; 10:277-86. [PMID: 23324604 PMCID: PMC3594286 DOI: 10.4161/rna.23315] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
CELF1 RNA-binding protein, otherwise called CUGBP1, associates and coordinates the degradation of GU-rich element (GRE) containing mRNA’s encoding factors important for cell growth, migration and apoptosis. Although many substrates of CELF1 have been identified, the biological significance of CELF1-mediated mRNA decay remains unclear. As the processes modulated by CELF1 are frequently disrupted in cancer, we investigated the expression and role of CELF1 in oral squamous cancer cells (OSCCs). We determined that CELF1 is reproducibly overexpressed in OSCC tissues and cell lines. Moreover, depletion of CELF1 reduced proliferation and increased apoptosis in OSCCs, but had negligible effect in non-transformed cells. We found that CELF1 associates directly with the 3′UTR of mRNAs encoding the pro-apoptotic factors BAD, BAX and JunD and mediates their rapid decay. Specifically, 3′UTR fragment analysis of JunD revealed that the GRE region is critical for binding with CELF1 and expression of JunD in oral cancer cells. In addition, silencing of CELF1 rendered BAD, BAX and JunD mRNAs stable and increased their protein expression in oral cancer cells. Taken together, these results support a critical role for CELF1 in modulating apoptosis and implicate this RNA-binding protein as a cancer marker and potential therapeutic target.
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Affiliation(s)
- Sudha Talwar
- Department of Craniofacial Biology and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
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12
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Vlasova-St Louis I, Dickson AM, Bohjanen PR, Wilusz CJ. CELFish ways to modulate mRNA decay. Biochim Biophys Acta 2013; 1829:695-707. [PMID: 23328451 DOI: 10.1016/j.bbagrm.2013.01.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/03/2013] [Accepted: 01/05/2013] [Indexed: 12/14/2022]
Abstract
The CELF family of RNA-binding proteins regulates many steps of mRNA metabolism. Although their best characterized function is in pre-mRNA splice site choice, CELF family members are also powerful modulators of mRNA decay. In this review we focus on the different modes of regulation that CELF proteins employ to mediate mRNA decay by binding to GU-rich elements. After starting with an overview of the importance of CELF proteins during development and disease pathogenesis, we then review the mRNA networks and cellular pathways these proteins regulate and the mechanisms by which they influence mRNA decay. Finally, we discuss how CELF protein activity is modulated during development and in response to cellular signals. We conclude by highlighting the priorities for new experiments in this field. This article is part of a Special Issue entitled: RNA Decay mechanisms.
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13
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Moon SL, Anderson JR, Kumagai Y, Wilusz CJ, Akira S, Khromykh AA, Wilusz J. A noncoding RNA produced by arthropod-borne flaviviruses inhibits the cellular exoribonuclease XRN1 and alters host mRNA stability. RNA 2012; 18:2029-40. [PMID: 23006624 PMCID: PMC3479393 DOI: 10.1261/rna.034330.112] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 08/17/2012] [Indexed: 05/25/2023]
Abstract
All arthropod-borne flaviviruses generate a short noncoding RNA (sfRNA) from the viral 3' untranslated region during infection due to stalling of the cellular 5'-to-3' exonuclease XRN1. We show here that formation of sfRNA also inhibits XRN1 activity. Cells infected with Dengue or Kunjin viruses accumulate uncapped mRNAs, decay intermediates normally targeted by XRN1. XRN1 repression also resulted in the increased overall stability of cellular mRNAs in flavivirus-infected cells. Importantly, a mutant Kunjin virus that cannot form sfRNA but replicates to normal levels failed to affect host mRNA stability or XRN1 activity. Expression of sfRNA in the absence of viral infection demonstrated that sfRNA formation was directly responsible for the stabilization of cellular mRNAs. Finally, numerous cellular mRNAs were differentially expressed in an sfRNA-dependent fashion in a Kunjin virus infection. We conclude that flaviviruses incapacitate XRN1 during infection and dysregulate host mRNA stability as a result of sfRNA formation.
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Affiliation(s)
- Stephanie L. Moon
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - John R. Anderson
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Yutaro Kumagai
- Laboratory of Host Defense, Immunology Frontier Research Center, Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Carol J. Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Shizuo Akira
- Laboratory of Host Defense, Immunology Frontier Research Center, Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Alexander A. Khromykh
- Australian Infectious Disease Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
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14
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Lee JE, Lee JY, Trembly J, Wilusz J, Tian B, Wilusz CJ. The PARN deadenylase targets a discrete set of mRNAs for decay and regulates cell motility in mouse myoblasts. PLoS Genet 2012; 8:e1002901. [PMID: 22956911 PMCID: PMC3431312 DOI: 10.1371/journal.pgen.1002901] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/02/2012] [Indexed: 11/22/2022] Open
Abstract
PARN is one of several deadenylase enzymes present in mammalian cells, and as such the contribution it makes to the regulation of gene expression is unclear. To address this, we performed global mRNA expression and half-life analysis on mouse myoblasts depleted of PARN. PARN knockdown resulted in the stabilization of 40 mRNAs, including that encoding the mRNA decay factor ZFP36L2. Additional experiments demonstrated that PARN knockdown induced an increase in Zfp36l2 poly(A) tail length as well as increased translation. The elements responsible for PARN-dependent regulation lie within the 3′ UTR of the mRNA. Surprisingly, changes in mRNA stability showed an inverse correlation with mRNA abundance; stabilized transcripts showed either no change or a decrease in mRNA abundance. Moreover, we found that stabilized mRNAs had reduced accumulation of pre–mRNA, consistent with lower transcription rates. This presents compelling evidence for the coupling of mRNA decay and transcription to buffer mRNA abundances. Although PARN knockdown altered decay of relatively few mRNAs, there was a much larger effect on global gene expression. Many of the mRNAs whose abundance was reduced by PARN knockdown encode factors required for cell migration and adhesion. The biological relevance of this observation was demonstrated by the fact that PARN KD cells migrate faster in wound-healing assays. Collectively, these data indicate that PARN modulates decay of a defined set of mRNAs in mammalian cells and implicate this deadenylase in coordinating control of genes required for cell movement. Almost all cellular mRNAs terminate in a 3′ poly(A) tail, the removal of which can induce both translational silencing and mRNA decay. Mammalian cells encode many poly(A)-specific exoribonucleases, but their individual roles are poorly understood. Here, we undertook an analysis of the role of PARN deadenylase in mouse myoblasts using global measurements of mRNA decay rates. Our results reveal that a discrete set of mRNAs exhibit altered mRNA decay as a result of PARN depletion and that stabilization is associated with increased poly(A) tail length and translation efficiency. We determined that stabilization of mRNAs does not generally result in their increased abundance, supporting the idea that mRNA decay is coupled to transcription. Importantly, knockdown of PARN has wide ranging effects on gene expression that specifically impact the extracellular matrix and cell migration.
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Affiliation(s)
- Jerome E. Lee
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ju Youn Lee
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, New Jersey, United States of America
| | - Jarrett Trembly
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail: (JW); (CJW)
| | - Bin Tian
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, New Jersey, United States of America
| | - Carol J. Wilusz
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail: (JW); (CJW)
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15
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Dickson AM, Anderson JR, Barnhart MD, Sokoloski KJ, Oko L, Opyrchal M, Galanis E, Wilusz CJ, Morrison TE, Wilusz J. Dephosphorylation of HuR protein during alphavirus infection is associated with HuR relocalization to the cytoplasm. J Biol Chem 2012; 287:36229-38. [PMID: 22915590 DOI: 10.1074/jbc.m112.371203] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We have demonstrated previously that the cellular HuR protein binds U-rich elements in the 3' untranslated region (UTR) of Sindbis virus RNA and relocalizes from the nucleus to the cytoplasm upon Sindbis virus infection in 293T cells. In this study, we show that two alphaviruses, Ross River virus and Chikungunya virus, lack the conserved high-affinity U-rich HuR binding element in their 3' UTRs but still maintain the ability to interact with HuR with nanomolar affinities through alternative binding elements. The relocalization of HuR protein occurs during Sindbis infection of multiple mammalian cell types as well as during infections with three other alphaviruses. Interestingly, the relocalization of HuR is not a general cellular reaction to viral infection, as HuR protein remained largely nuclear during infections with dengue and measles virus. Relocalization of HuR in a Sindbis infection required viral gene expression, was independent of the presence of a high-affinity U-rich HuR binding site in the 3' UTR of the virus, and was associated with an alteration in the phosphorylation state of HuR. Sindbis virus-induced HuR relocalization was mechanistically distinct from the movement of HuR observed during a cellular stress response, as there was no accumulation of caspase-mediated HuR cleavage products. Collectively, these data indicate that virus-induced HuR relocalization to the cytoplasm is specific to alphavirus infections and is associated with distinct posttranslational modifications of this RNA-binding protein.
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Affiliation(s)
- Alexa M Dickson
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
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16
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Neff AT, Lee JY, Wilusz J, Tian B, Wilusz CJ. Global analysis reveals multiple pathways for unique regulation of mRNA decay in induced pluripotent stem cells. Genome Res 2012; 22:1457-67. [PMID: 22534399 PMCID: PMC3409259 DOI: 10.1101/gr.134312.111] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Pluripotency is a unique state in which cells can self-renew indefinitely but also retain the ability to differentiate into other cell types upon receipt of extracellular cues. Although it is clear that stem cells have a distinct transcriptional program, little is known about how alterations in post-transcriptional mechanisms, such as mRNA turnover, contribute to the achievement and maintenance of pluripotency. Here we have assessed the rates of decay for the majority of mRNAs expressed in induced pluripotent stem (iPS) cells and the fully differentiated human foreskin fibroblasts (HFFs) they were derived from. Comparison of decay rates in the two cell types led to the discovery of three independent regulatory mechanisms that allow coordinated turnover of specific groups of mRNAs. One mechanism results in increased stability of many histone mRNAs in iPS cells. A second pathway stabilizes a large set of zinc finger protein mRNAs, potentially through reduced levels of miRNAs that target them. Finally, a group of transcripts bearing 3' UTR C-rich sequence elements, many of which encode transcription factors, are significantly less stable in iPS cells. Intriguingly, two poly(C)-binding proteins that recognize this type of element are reciprocally expressed in iPS and HFF cells. Overall, our results highlight the importance of post-transcriptional control in pluripotent cells and identify miRNAs and RNA-binding proteins whose activity may coordinately control expression of a wide range of genes in iPS cells.
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Affiliation(s)
- Ashley T Neff
- Program in Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
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17
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Palusa S, Ndaluka C, Bowen RA, Wilusz CJ, Wilusz J. The 3' untranslated region of the rabies virus glycoprotein mRNA specifically interacts with cellular PCBP2 protein and promotes transcript stability. PLoS One 2012; 7:e33561. [PMID: 22438951 PMCID: PMC3306424 DOI: 10.1371/journal.pone.0033561] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 02/14/2012] [Indexed: 12/25/2022] Open
Abstract
Viral polymerase entry and pausing at intergenic junctions is predicted to lead to a defined polarity in the levels of rhabdovirus gene expression. Interestingly, we observed that the rabies virus glycoprotein mRNA is differentially over-expressed based on this model relative to other transcripts during infection of 293T cells. During infection, the rabies virus glycoprotein mRNA also selectively interacts with the cellular poly(rC)-binding protein 2 (PCBP2), a factor known to influence mRNA stability. Reporter assays performed both in electroporated cells and in a cell-free RNA decay system indicate that the conserved portion of the 3' UTR of the rabies virus glycoprotein mRNA contains an RNA stability element. PCBP2 specifically interacts with reporter transcripts containing this 72 base 3' UTR sequence. Furthermore, the PCBP2 interaction is directly associated with the stability of reporter transcripts. Therefore, we conclude that PCBP2 specifically and selectively interacts with the rabies virus glycoprotein mRNA and that this interaction may contribute to the post-transcriptional regulation of glycoprotein expression.
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Affiliation(s)
- Saiprasad Palusa
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Christina Ndaluka
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Richard A. Bowen
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Carol J. Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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18
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Abstract
As mRNAs are generated, they are clothed with proteins to form messenger ribonucleoprotein particles (mRNPs), which are then actively remodeled during various steps of gene expression. Franks et al. (2010) now show that mRNP remodeling is required even for the death of an mRNA.
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, 80523, USA
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19
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Abstract
An increasing number of dominantly inherited diseases have now been linked with expansion of short repeats within specific genes. Although some of these expansions affect protein function or result in haploinsufficiency, a significant portion cause pathogenesis through production of toxic RNA molecules that alter cellular metabolism. In this review, we examine the criteria that influence toxicity of these mutant RNAs and discuss new developments in therapeutic approaches.
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Affiliation(s)
- Alexa M Dickson
- Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80523, USA
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20
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Abstract
Control of mRNA translation and localization plays an important role in many developmental contexts. In this issue of Developmental Cell, Reveal et al. show through analysis of the oskar mRNA in Drosophila embryos that regulatory elements within mRNAs can act in trans to influence the behavior of other mRNA molecules.
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523-1682, USA
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21
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Zhang L, Lee JE, Wilusz J, Wilusz CJ. The RNA-binding protein CUGBP1 regulates stability of tumor necrosis factor mRNA in muscle cells: implications for myotonic dystrophy. J Biol Chem 2008; 283:22457-63. [PMID: 18559347 DOI: 10.1074/jbc.m802803200] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Type I myotonic dystrophy (DM1) is caused by a triplet repeat expansion in the 3'-untranslated region (UTR) of the dystrophia myotonia protein kinase (DMPK) gene. Pathogenesis is closely linked with production of a toxic RNA from the mutant allele, which interferes with function of several RNA-binding proteins, including CUGBP1. Here we show that expression of a mutant DMPK 3'-UTR containing 960 CUG repeats is sufficient to increase expression and stability of an mRNA encoding the potent proinflammatory cytokine, tumor necrosis factor (TNF). CUGBP1 specifically recognizes sequences within the TNF 3'-UTR that are dissimilar from its canonical UG-rich binding site. Depletion of CUGBP1 from mouse myoblasts results in increased abundance of TNF mRNA through stabilization of the transcript. Moreover, activation of the protein kinase C pathway by treatment with phorbol ester, which has been shown previously to result in CUGBP1 phosphorylation, also causes TNF mRNA stabilization. Our results suggest that the elevated serum TNF seen in DM1 patients may be derived from muscle where it is induced by expression of toxic DMPK RNA. Importantly, overexpression of this potent cytokine could contribute to the muscle wasting and insulin resistance that are characteristic of this debilitating disease.
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Affiliation(s)
- Libin Zhang
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
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22
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA.
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23
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Ibrahim H, Wilusz J, Wilusz CJ. RNA recognition by 3'-to-5' exonucleases: the substrate perspective. Biochim Biophys Acta 2007; 1779:256-65. [PMID: 18078842 DOI: 10.1016/j.bbagrm.2007.11.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 11/08/2007] [Accepted: 11/09/2007] [Indexed: 12/30/2022]
Abstract
The 3'-to-5' exonucleolytic decay and processing of a variety of RNAs is an essential feature of RNA metabolism in all cells. The 3'-5' exonucleases, and in particular the exosome, are involved in a large number of pathways from 3' processing of rRNA, snRNA and snoRNA, to decay of mRNAs and mRNA surveillance. The potent enzymes performing these reactions are regulated to prevent processing of inappropriate substrates whilst mature RNA molecules exhibit several attributes that enable them to evade 3'-5' attack. How does an enzyme perform such selective activities on different substrates? The goal of this review is to provide an overview and perspective of available data on the underlying principles for the recognition of RNA substrates by 3'-to-5' exonucleases.
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Affiliation(s)
- Hend Ibrahim
- Colorado State University, Department of Microbiology, Immunology and Pathology, Fort Collins, CO 80525, USA
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24
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Kurt TD, Perrott MR, Wilusz CJ, Wilusz J, Supattapone S, Telling GC, Zabel MD, Hoover EA. Efficient in vitro amplification of chronic wasting disease PrPRES. J Virol 2007; 81:9605-8. [PMID: 17553879 PMCID: PMC1951436 DOI: 10.1128/jvi.00635-07] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2007] [Accepted: 05/30/2007] [Indexed: 11/20/2022] Open
Abstract
Chronic wasting disease (CWD) of cervids is associated with conversion of the normal cervid prion protein, PrP(C), to a protease-resistant conformer, PrP(CWD). Here we report the use of both nondenaturing amplification and protein-misfolding cyclic amplification (PMCA) to amplify PrP(CWD) in vitro. Normal brains from deer, transgenic mice expressing cervid PrP(C) [Tg(cerPrP)1536 mice], and ferrets supported amplification. PMCA using normal Tg(cerPrP)1536 brains as the PrP(C) substrate produced >6.5 x 10(9)-fold amplification after six rounds. Highly efficient in vitro amplification of PrP(CWD) is a significant step toward detection of PrP(CWD) in the body fluids or excreta of CWD-susceptible species.
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Affiliation(s)
- Timothy D Kurt
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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25
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Bergman N, Moraes KCM, Anderson JR, Zaric B, Kambach C, Schneider RJ, Wilusz CJ, Wilusz J. Lsm proteins bind and stabilize RNAs containing 5' poly(A) tracts. Nat Struct Mol Biol 2007; 14:824-31. [PMID: 17694069 DOI: 10.1038/nsmb1287] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 07/09/2007] [Indexed: 01/15/2023]
Abstract
Many orthopoxvirus messenger RNAs have an unusual nontemplated poly(A) tract of 5 to 40 residues at the 5' end. The precise function of this feature is unknown. Here we show that 5' poly(A) tracts are able to repress RNA decay by inhibiting 3'-to-5' exonucleases as well as decapping of RNA substrates. UV cross-linking analysis demonstrated that the Lsm complex associates with the 5' poly(A) tract. Furthermore, recombinant Lsm1-7 complex specifically binds 5' poly(A) tracts 10 to 21 nucleotides in length, consistent with the length of 5' poly(A) required for stabilization. Knockdown of Lsm1 abrogates RNA stabilization by the 5' poly(A) tract. We propose that the Lsm complex simultaneously binds the 3' and 5' ends of these unusual messenger RNAs and thereby prevents 3'-to-5' decay. The implications of this phenomenon for cellular mRNA decay are discussed.
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Affiliation(s)
- Naomi Bergman
- Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, Colorado 80525, USA
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26
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Abstract
In this issue of Molecular Cell, demonstrate that the RNA binding protein HuR selectively up- or downregulates the stability of the SIRT1 mRNA (which encodes an important regulatory deacetylase) depending upon phosphorylation by Chk2.
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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27
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Abstract
When considering the control of gene expression, the focus has traditionally been on transcriptional regulation. Recently, however, the large contribution made by mRNA decay has become difficult to ignore. Large-scale analyses indicate that as many as half of all changes in the amounts of mRNA in some responses can be attributed to altered rates of decay. In this article, we discuss some of the mechanisms that are used by the cell to mediate and regulate this intriguing process.
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Affiliation(s)
- Nicole L Garneau
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
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28
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29
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Abstract
It is becoming clear that viruses interface with the mRNA decay machinery in a variety of ways during an infection. First, RNA viruses in particular must evade the mRNA decay machinery long enough to replicate and establish infection. Second, many viruses usurp or augment cellular mRNA decay pathways to regulate or selectively express their own genes, often inducing massive decay of the host transcripttome. Finally, temporal progression of a viral infection can depend on regulated decay of specific viral transcripts. Therefore, in order to fully understand viral biology, we must take into account the interactions between viruses and the mRNA decay machinery. This approach gives insights into regulatory mechanisms of cellular mRNA decay, as well as reveals novel ways to influence the outcome of viral infections.
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Affiliation(s)
- Kevin J Sokoloski
- Colorado State University, Department of Microbiology, Immunology and Pathology, Fort Collins, Colorado 80523-1682, USA
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30
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Anderson JR, Mukherjee D, Muthukumaraswamy K, Moraes KCM, Wilusz CJ, Wilusz J. Sequence-specific RNA binding mediated by the RNase PH domain of components of the exosome. RNA 2006; 12:1810-6. [PMID: 16912217 PMCID: PMC1581985 DOI: 10.1261/rna.144606] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We have previously demonstrated that PM-Scl-75, a component of the human exosome complex involved in RNA maturation and mRNA decay, can specifically interact with RNAs containing an AU-rich instability element. Through the analysis of a series of deletion mutants, we have now shown that a 266 amino acid fragment representing the RNase PH domain is responsible for the sequence-specific binding to AU-rich elements. Furthermore, we found that the RNase PH domains from two other exosomal components, OIP2 and RRP41, as well as from Escherichia coli polynucleotide phosphorylase, are all capable of specifically interacting with RNAs containing an AU-rich element with similar affinities. Finally, we demonstrate that the interaction of the RNase PH domain of PM-Scl-75 is readily competed by poly(U), but only inefficiently using other homopolymeric RNAs. These data demonstrate that RNase PH domains in general have an affinity for U- and AU-rich sequences, and broaden the potential role in RNA biology of proteins containing these domains.
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Affiliation(s)
- John R Anderson
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA
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31
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Abstract
CUG-BP is the human homolog of the Xenopus EDEN-BP, which was shown previously to bind to mRNAs, such as c-mos, that exhibit rapid deadenylation following fertilization of the oocyte. While several studies have focused on roles of CUG-BP as a splicing or translation regulator in mammalian cells, its role in mRNA decay has not been examined in detail. Here, we have used an in vitro deadenylation assay to dissect the function of CUG-BP in the decay of two ARE-containing mRNAs: c-fos and TNFalpha. CUG-BP binds specifically to both of these RNAs and stimulates poly(A) shortening by PARN. Moreover, CUG-BP interacts with PARN in extracts by coimmunoprecipitation, and this interaction can be recapitulated using recombinant proteins. CUG-BP, therefore, is the first RNA-binding protein shown to directly recruit a deadenylase to an RNA substrate.
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Affiliation(s)
- Karen C M Moraes
- Department of Microbiology, Immunology & Pathology, College of Veterinary Medicine & Biomedical Sciences, Colorado State University, Fort Collins, 80523, USA
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32
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Palaniswamy V, Moraes KCM, Wilusz CJ, Wilusz J. Nucleophosmin is selectively deposited on mRNA during polyadenylation. Nat Struct Mol Biol 2006; 13:429-35. [PMID: 16604083 PMCID: PMC2811576 DOI: 10.1038/nsmb1080] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 03/06/2006] [Indexed: 12/19/2022]
Abstract
Nucleophosmin (NPM), an abundant, predominantly nucleolar protein that influences numerous cellular processes, was shown to specifically associate with the bodies of messenger RNAs as a result of the process of 3'-end formation. NPM deposition requires polyadenylation but not the 3' cleavage event to occur on the transcript. Furthermore, the protein does not associate with RNAs bearing a preformed poly(A) tail or with mRNAs that have undergone cleavage but not polyadenylation. A region within 10 bases upstream of the AAUAAA element is required for NPM association, but deposition of the protein seems to be sequence independent. NPM association with poly(A)(+) mRNAs was also demonstrated in vivo. NPM, therefore, represents a mark left on transcripts as a result of 3'-end processing and may have a role in one or more of a variety of post-transcriptional processes influenced by the polyadenylation event.
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Affiliation(s)
- Viswanathan Palaniswamy
- Department of Microbiology, Immunology & Pathology, Colorado State University, 1619 Campus Delivery, Fort Collins, Colorado 80523, USA
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33
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Abstract
Over the last five years Sm-like (Lsm) proteins have emerged as important players in many aspects of RNA metabolism, including splicing, nuclear RNA processing and messenger RNA decay. However, their precise function in these pathways remains somewhat obscure. In contrast, the role of the bacterial Lsm protein Hfq, which bears striking similarities in both structure and function to Lsm proteins, is much better characterized. In this perspective, we have highlighted several functions that Hfq shares with Lsm proteins and put forward hypotheses based on parallels between the two that might further the understanding of Lsm function.
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology & Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
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Opyrchal M, Anderson JR, Sokoloski KJ, Wilusz CJ, Wilusz J. A cell-free mRNA stability assay reveals conservation of the enzymes and mechanisms of mRNA decay between mosquito and mammalian cell lines. Insect Biochem Mol Biol 2005; 35:1321-34. [PMID: 16291088 DOI: 10.1016/j.ibmb.2005.08.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 08/09/2005] [Accepted: 08/10/2005] [Indexed: 05/05/2023]
Abstract
The rate of mRNA turnover is an important determinant of levels of gene expression. Although this process has been studied extensively in mammalian cells and yeast, relatively little is known about the mRNA decay pathways in insects. Our analysis found that the vast majority of components of the mRNA decay machinery are conserved between humans and mosquitoes. Moreover, the half-lives of Aedes albopictus mRNAs are within a similar range to those of mammalian mRNAs. In order to investigate mechanistic aspects of mRNA decay in mosquitoes, we developed an in vitro system using cytoplasmic S100 extracts from A. albopictus C6/36 cells. Using this decay assay, we show here that all the pathways of mRNA turnover that have been observed in mammalian cells (deadenylation, decapping, 3'-to-5' exonucleolytic decay and 5'-to-3' exonucleolytic decay) are active in C6/36 extracts. Finally, we present compelling evidence that the major deadenylase in C6/36 extracts is likely to be a homolog of the human poly(A) specific ribonuclease, PARN. Our results suggest a high level of conservation in the factors and pathways of mRNA decay between mosquitoes and humans.
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Affiliation(s)
- Mateusz Opyrchal
- Department of Microbiology, Immunology & Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, 80523, USA
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Duttagupta R, Tian B, Wilusz CJ, Khounh DT, Soteropoulos P, Ouyang M, Dougherty JP, Peltz SW. Global analysis of Pub1p targets reveals a coordinate control of gene expression through modulation of binding and stability. Mol Cell Biol 2005; 25:5499-513. [PMID: 15964806 PMCID: PMC1156976 DOI: 10.1128/mcb.25.13.5499-5513.2005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Regulation of mRNA turnover is an important cellular strategy for posttranscriptional control of gene expression, mediated by the interplay of cis-acting sequences and associated trans-acting factors. Pub1p, an ELAV-like yeast RNA-binding protein with homology to T-cell internal antigen 1 (TIA-1)/TIA-1-related protein (TIAR), is an important modulator of the decay of two known classes of mRNA. Our goal in this study was to determine the range of mRNAs whose stability is dependent on Pub1p, as well as to identify specific transcripts that directly bind to this protein. We have examined global mRNA turnover in isogenic PUB1 and pub1delta strains through gene expression analysis and demonstrate that 573 genes exhibit a significant reduction in half-life in a pub1delta strain. We also examine the binding specificity of Pub1p using affinity purification followed by microarray analysis to comprehensively distinguish between direct and indirect targets and find that Pub1p significantly binds to 368 cellular transcripts. Among the Pub1p-associated mRNAs, 53 transcripts encoding proteins involved in ribosomal biogenesis and cellular metabolism are selectively destabilized in the pub1delta strain. In contrast, genes involved in transporter activity demonstrate association with Pub1p but display no measurable changes in transcript stability. Characterization of two candidate genes, SEC53 and RPS16B, demonstrate that both Pub1p-dependent regulation of stability and Pub1p binding require 3' untranslated regions, which harbor distinct sequence motifs. These results suggest that Pub1p binds to discrete subsets of cellular transcripts and posttranscriptionally regulates their expression at multiple levels.
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Affiliation(s)
- Radharani Duttagupta
- Department of Molecular Genetics, Microbiology, and Immunology, UMDNJ-Robert Wood Johnson Medical School, 675 Hoes Ln., Piscataway, New Jersey 08854-5627, USA
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36
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Abstract
The process of mRNA decay is integral to the post-transcriptional control of gene expression. The enzymes of the pathway have been identified, and now several laboratories have found that the mRNA decay machinery is localized to discrete cytoplasmic foci whose existence had not been suspected previously. In addition, we can now see that mRNA turnover is a means to coordinate gene expression, first through integration with control of transcription, export and translation of mRNAs, and second through enabling mRNAs involved in similar processes to decay at similar rates. These and other aspects of the field are discussed.
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
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37
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Abstract
The majority of messenger RNA (mRNA) decay in mammalian cells appears to be the work of a series of RNA exoribonucleases. A set of multiple poly(A)-specific deadenylases has been identified, some, if not most, of which are likely to play a role in the key first step of mRNA turnover--the regulated shortening of the poly(A) tail. After deadenylation, the transcript likely gets degraded by either a 5'-to-3' or a 3'-to-5' exonucleolytic pathway. Interestingly, multiple exonucleases have been identified for both of these pathways that appear to form multicomponent complexes with diverse roles in cellular biology. Therefore these enzymes appear not only to be important components of the mRNA turnover machinery, but also may function in a networked fashion in the post-transcriptional control of gene expression.
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Affiliation(s)
- David T Fritz
- Department of Biochemistry and Molecular Biology, UMDNJ-New Jersey Medical School, Newark, NJ 07101, USA
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38
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Duttagupta R, Vasudevan S, Wilusz CJ, Peltz SW. A yeast homologue of Hsp70, Ssa1p, regulates turnover of the MFA2 transcript through its AU-rich 3' untranslated region. Mol Cell Biol 2003; 23:2623-32. [PMID: 12665566 PMCID: PMC152564 DOI: 10.1128/mcb.23.8.2623-2632.2003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many eukaryotic mRNAs exhibit regulated decay in response to cellular signals. AU-rich elements (AREs) identified in the 3' untranslated region (3'-UTR) of several such mRNAs play a critical role in controlling the half-lives of these transcripts. The yeast ARE-containing mRNA, MFA2, has been studied extensively and is degraded by a deadenylation-dependent mechanism. However, the trans-acting factors that promote the rapid decay of MFA2 have not been identified. Our results suggest that the chaperone protein Hsp70, encoded by the SSA family of genes, is involved in modulating MFA2 mRNA decay. MFA2 is specifically stabilized in a strain bearing a temperature-sensitive mutation in the SSA1 gene. Furthermore, an AU-rich region within the 3'-UTR of the message is both necessary and sufficient to confer this regulation. Stabilization occurs as a result of slower deadenylation in the ssa1(ts) strain, suggesting that Hsp70 is required for activation of the turnover pathway.
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Affiliation(s)
- Radharani Duttagupta
- Department of Molecular Genetics, Microbiology and Immunology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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Abstract
Gene expression is an inherently complex process and errors often occur during the transcription and processing of mRNAs. Several surveillance mechanisms have evolved to check the fidelity at each step of mRNA manufacture. Two recent reports describe the identification of a novel pathway in eukaryotes that recognizes and degrades mRNAs that lack a stop codon. The non-stop decay mechanism releases ribosomes stalled at the 3' end of a mRNA and stimulates the exosome to rapidly degrade the transcript.
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Affiliation(s)
- Shobha Vasudevan
- Department of Molecular Genetics, Microbiology and Immunology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
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40
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Affiliation(s)
- C J Wilusz
- Department of Molecular Genetics and Microbiology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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41
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Evans D, Perez I, MacMorris M, Leake D, Wilusz CJ, Blumenthal T. A complex containing CstF-64 and the SL2 snRNP connects mRNA 3' end formation and trans-splicing in C. elegans operons. Genes Dev 2001; 15:2562-71. [PMID: 11581161 PMCID: PMC312790 DOI: 10.1101/gad.920501] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Polycistronic pre-mRNAs from Caenorhabditis elegans are processed by 3' end formation of the upstream mRNA and SL2-specific trans-splicing of the downstream mRNA. These processes usually occur within an approximately 100-nucleotide region and are mechanistically coupled. In this paper, we report a complex in C. elegans extracts containing the 3' end formation protein CstF-64 and the SL2 snRNP. This complex, immunoprecipitated with alphaCstF-64 antibody, contains SL2 RNA, but not SL1 RNA or other U snRNAs. Using mutational analysis we have been able to uncouple SL2 snRNP function and identity. SL2 RNA with a mutation in stem/loop III is functional in vivo as a trans-splice donor, but fails to splice to SL2-accepting trans-splice sites, suggesting that it has lost its identity as an SL2 snRNP. Importantly, stem/loop III mutations prevent association of SL2 RNA with CstF-64. In contrast, a mutation in stem II that inactivates the SL2 snRNP still permits complex formation with CstF-64. Therefore, SL2 RNA stem/loop III is required for both SL2 identity and formation of a complex containing CstF-64, but not for trans-splicing. These results provide a molecular framework for the coupling of 3' end formation and trans-splicing in the processing of polycistronic pre-mRNAs from C. elegans operons.
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Affiliation(s)
- D Evans
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Denver, CO 80262, USA
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Wilusz CJ, Gao M, Jones CL, Wilusz J, Peltz SW. Poly(A)-binding proteins regulate both mRNA deadenylation and decapping in yeast cytoplasmic extracts. RNA 2001; 7:1416-1424. [PMID: 11680846 PMCID: PMC1370185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The pathway of mRNA degradation has been extensively studied in the yeast, Saccharomyces cerevisiae, and it is now clear that many mRNAs decay by a deadenylation-dependent mechanism. Although several of the factors required for mRNA decay have been identified, the regulation and precise roles of many of the proteins involved remains unclear. We have developed an in vitro system that recapitulates both the deadenylation and the decapping steps of mRNA decay. Furthermore, both deadenylation and decapping are inhibited by poly(A) binding proteins in our assay. Our system has allowed us to separate the decay process from translation and we have shown that the poly(A) tail is capable of inhibiting decapping in an eIF4E-independent manner. Our in vitro system should prove invaluable in dissecting the mechanisms of mRNA turnover.
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Affiliation(s)
- C J Wilusz
- Department of Molecular Genetics and Microbiology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway 08854, USA
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Abstract
The levels of cellular messenger RNA transcripts can be regulated by controlling the rate at which the mRNA decays. Because decay rates affect the expression of specific genes, they provide a cell with flexibility in effecting rapid change. Moreover, many clinically relevant mRNAs--including several encoding cytokines, growth factors and proto-oncogenes--are regulated by differential RNA stability. But what are the sequence elements and factors that control the half-lives of mRNAs?
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Affiliation(s)
- C J Wilusz
- Department of Molecular Genetics and Microbiology, Robert Wood Johnson Medical School-UMDNJ, Piscataway, New Jersey 08854, USA
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Gao M, Wilusz CJ, Peltz SW, Wilusz J. A novel mRNA-decapping activity in HeLa cytoplasmic extracts is regulated by AU-rich elements. EMBO J 2001; 20:1134-43. [PMID: 11230136 PMCID: PMC145468 DOI: 10.1093/emboj/20.5.1134] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2000] [Revised: 01/02/2001] [Accepted: 01/05/2001] [Indexed: 11/14/2022] Open
Abstract
While decapping plays a major role in mRNA turnover in yeast, biochemical evidence for a similar activity in mammalian cells has been elusive. We have now identified a decapping activity in HeLa cytoplasmic extracts that releases (7me)GDP from capped transcripts. Decapping is activated in extracts by the addition of (7me)GpppG, which specifically sequesters cap-binding proteins such as eIF4E and the deadenylase DAN/PARN. Similar to in vivo observations, the presence of a poly(A) tail represses decapping of RNAs in vitro in a poly(A)-binding protein-dependent fashion. AU-rich elements (AREs), which act as regulators of mRNA stability in vivo, are potent stimulators of decapping in vitro. The stimulation of decapping by AREs requires sequence-specific ARE-binding proteins. These data suggest that cap recognition and decapping play key roles in mediating mRNA turnover in mammalian cells.
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Affiliation(s)
| | - Carol J. Wilusz
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, Newark, NJ 07103 and
Department of Molecular Genetics and Microbiology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA Corresponding author e-mail:
| | - Stuart W. Peltz
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, Newark, NJ 07103 and
Department of Molecular Genetics and Microbiology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA Corresponding author e-mail:
| | - Jeffrey Wilusz
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, Newark, NJ 07103 and
Department of Molecular Genetics and Microbiology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA Corresponding author e-mail:
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