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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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Wang X, Yu D, Yu J, Hu H, Hang R, Amador Z, Chen Q, Chai J, Chen X. Toll/interleukin-1 receptor (TIR) domain-containing proteins have NAD-RNA decapping activity. Nat Commun 2024; 15:2261. [PMID: 38480720 PMCID: PMC10937652 DOI: 10.1038/s41467-024-46499-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 02/29/2024] [Indexed: 03/17/2024] Open
Abstract
The occurrence of NAD+ as a non-canonical RNA cap has been demonstrated in diverse organisms. TIR domain-containing proteins present in all kingdoms of life act in defense responses and can have NADase activity that hydrolyzes NAD+. Here, we show that TIR domain-containing proteins from several bacterial and one archaeal species can remove the NAM moiety from NAD-capped RNAs (NAD-RNAs). We demonstrate that the deNAMing activity of AbTir (from Acinetobacter baumannii) on NAD-RNA specifically produces a cyclic ADPR-RNA, which can be further decapped in vitro by known decapping enzymes. Heterologous expression of the wild-type but not a catalytic mutant AbTir in E. coli suppressed cell propagation and reduced the levels of NAD-RNAs from a subset of genes before cellular NAD+ levels are impacted. Collectively, the in vitro and in vivo analyses demonstrate that TIR domain-containing proteins can function as a deNAMing enzyme of NAD-RNAs, raising the possibility of TIR domain proteins acting in gene expression regulation.
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Affiliation(s)
- Xufeng Wang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, 100871, China
- Beijing Advanced Center of RNA Biology (BEACON), Peking University, Beijing, 100871, China
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, 92521, USA
| | - Dongli Yu
- Institute of Biochemistry, University of Cologne, Cologne, 50674, Germany
- Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02215, USA
| | - Jiancheng Yu
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Hao Hu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, 100871, China
- Beijing Advanced Center of RNA Biology (BEACON), Peking University, Beijing, 100871, China
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, 92521, USA
| | - Runlai Hang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, 100871, China
- Beijing Advanced Center of RNA Biology (BEACON), Peking University, Beijing, 100871, China
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, 92521, USA
| | - Zachary Amador
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, 92521, USA
| | - Qi Chen
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
- Molecular Medicine Program, Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Jijie Chai
- Institute of Biochemistry, University of Cologne, Cologne, 50674, Germany
- Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Xuemei Chen
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, 100871, China.
- Beijing Advanced Center of RNA Biology (BEACON), Peking University, Beijing, 100871, China.
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3
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Potužník JF, Cahova H. If the 5' cap fits (wear it) - Non-canonical RNA capping. RNA Biol 2024; 21:1-13. [PMID: 39007883 PMCID: PMC11253889 DOI: 10.1080/15476286.2024.2372138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 06/18/2024] [Indexed: 07/16/2024] Open
Abstract
RNA capping is a prominent RNA modification that influences RNA stability, metabolism, and function. While it was long limited to the study of the most abundant eukaryotic canonical m7G cap, the field recently went through a large paradigm shift with the discovery of non-canonical RNA capping in bacteria and ultimately all domains of life. The repertoire of non-canonical caps has expanded to encompass metabolite caps, including NAD, FAD, CoA, UDP-Glucose, and ADP-ribose, alongside alarmone dinucleoside polyphosphate caps, and methylated phosphate cap-like structures. This review offers an introduction into the field, presenting a summary of the current knowledge about non-canonical RNA caps. We highlight the often still enigmatic biological roles of the caps together with their processing enzymes, focusing on the most recent discoveries. Furthermore, we present the methods used for the detection and analysis of these non-canonical RNA caps and thus provide an introduction into this dynamic new field.
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Affiliation(s)
- Jiří František Potužník
- Institute of Organic Chemistry and Biochemistry of the CAS, Prague 6, Czechia
- Department of Cell Biology, Charles University, Faculty of Science, Prague 2, Czechia
| | - Hana Cahova
- Institute of Organic Chemistry and Biochemistry of the CAS, Prague 6, Czechia
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4
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Gomes-Filho JV, Breuer R, Morales-Filloy HG, Pozhydaieva N, Borst A, Paczia N, Soppa J, Höfer K, Jäschke A, Randau L. Identification of NAD-RNA species and ADPR-RNA decapping in Archaea. Nat Commun 2023; 14:7597. [PMID: 37989750 PMCID: PMC10663502 DOI: 10.1038/s41467-023-43377-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 11/07/2023] [Indexed: 11/23/2023] Open
Abstract
NAD is a coenzyme central to metabolism that also serves as a 5'-terminal cap for bacterial and eukaryotic transcripts. Thermal degradation of NAD can generate nicotinamide and ADP-ribose (ADPR). Here, we use LC-MS/MS and NAD captureSeq to detect and identify NAD-RNAs in the thermophilic model archaeon Sulfolobus acidocaldarius and in the halophilic mesophile Haloferax volcanii. None of the four Nudix proteins of S. acidocaldarius catalyze NAD-RNA decapping in vitro, but one of the proteins (Saci_NudT5) promotes ADPR-RNA decapping. NAD-RNAs are converted into ADPR-RNAs, which we detect in S. acidocaldarius total RNA. Deletion of the gene encoding the 5'-3' exonuclease Saci-aCPSF2 leads to a 4.5-fold increase in NAD-RNA levels. We propose that the incorporation of NAD into RNA acts as a degradation marker for Saci-aCPSF2. In contrast, ADPR-RNA is processed by Saci_NudT5 into 5'-p-RNAs, providing another layer of regulation for RNA turnover in archaeal cells.
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Affiliation(s)
| | - Ruth Breuer
- Faculty of Biology, Philipps-Universität Marburg, Marburg, Germany
| | | | | | - Andreas Borst
- Institute for Molecular Biosciences, Biocentre, Goethe-University, Frankfurt am Main, Germany
| | - Nicole Paczia
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Jörg Soppa
- Institute for Molecular Biosciences, Biocentre, Goethe-University, Frankfurt am Main, Germany
| | - Katharina Höfer
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- SYNMIKRO, Center for Synthetic Microbiology, Marburg, Germany
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany
| | - Lennart Randau
- Faculty of Biology, Philipps-Universität Marburg, Marburg, Germany.
- SYNMIKRO, Center for Synthetic Microbiology, Marburg, Germany.
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5
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Sherwood AV, Rivera-Rangel LR, Ryberg LA, Larsen HS, Anker KM, Costa R, Vågbø CB, Jakljevič E, Pham LV, Fernandez-Antunez C, Indrisiunaite G, Podolska-Charlery A, Grothen JER, Langvad NW, Fossat N, Offersgaard A, Al-Chaer A, Nielsen L, Kuśnierczyk A, Sølund C, Weis N, Gottwein JM, Holmbeck K, Bottaro S, Ramirez S, Bukh J, Scheel TKH, Vinther J. Hepatitis C virus RNA is 5'-capped with flavin adenine dinucleotide. Nature 2023:10.1038/s41586-023-06301-3. [PMID: 37407817 DOI: 10.1038/s41586-023-06301-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 06/08/2023] [Indexed: 07/07/2023]
Abstract
RNA viruses have evolved elaborate strategies to protect their genomes, including 5' capping. However, until now no RNA 5' cap has been identified for hepatitis C virus1,2 (HCV), which causes chronic infection, liver cirrhosis and cancer3. Here we demonstrate that the cellular metabolite flavin adenine dinucleotide (FAD) is used as a non-canonical initiating nucleotide by the viral RNA-dependent RNA polymerase, resulting in a 5'-FAD cap on the HCV RNA. The HCV FAD-capping frequency is around 75%, which is the highest observed for any RNA metabolite cap across all kingdoms of life4-8. FAD capping is conserved among HCV isolates for the replication-intermediate negative strand and partially for the positive strand. It is also observed in vivo on HCV RNA isolated from patient samples and from the liver and serum of a human liver chimeric mouse model. Furthermore, we show that 5'-FAD capping protects RNA from RIG-I mediated innate immune recognition but does not stabilize the HCV RNA. These results establish capping with cellular metabolites as a novel viral RNA-capping strategy, which could be used by other viruses and affect anti-viral treatment outcomes and persistence of infection.
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Affiliation(s)
- Anna V Sherwood
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Lizandro R Rivera-Rangel
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Line A Ryberg
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Helena S Larsen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Klara M Anker
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Rui Costa
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Cathrine B Vågbø
- Proteomics and Modomics Experimental Core (PROMEC), Norwegian University of Science and Technology and the Central Norway Regional Health Authority, Trondheim, Norway
| | - Eva Jakljevič
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Long V Pham
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Carlota Fernandez-Antunez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Gabriele Indrisiunaite
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Agnieszka Podolska-Charlery
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Julius E R Grothen
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Nicklas W Langvad
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Nicolas Fossat
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Anna Offersgaard
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Amal Al-Chaer
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Louise Nielsen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Anna Kuśnierczyk
- Proteomics and Modomics Experimental Core (PROMEC), Norwegian University of Science and Technology and the Central Norway Regional Health Authority, Trondheim, Norway
| | - Christina Sølund
- Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen N, Denmark
| | - Nina Weis
- Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen N, Denmark
| | - Judith M Gottwein
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Kenn Holmbeck
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Sandro Bottaro
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Santseharay Ramirez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark.
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark.
| | - Troels K H Scheel
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark.
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark.
- Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY, USA.
| | - Jeppe Vinther
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark.
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6
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Zhang Y, Gan W, Ru N, Xue Z, Chen W, Chen Z, Wang H, Zheng X. Comprehensive multi-omics analysis reveals m7G-related signature for evaluating prognosis and immunotherapy efficacy in osteosarcoma. J Bone Oncol 2023; 40:100481. [PMID: 37139222 PMCID: PMC10149372 DOI: 10.1016/j.jbo.2023.100481] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 05/05/2023] Open
Abstract
Background Osteosarcoma is one of the most prevalent bone malignancies with a poor prognosis. The N7-methylguanosine (m7G) modification facilitates the modification of RNA structure and function tightly associated with cancer. Nonetheless, there is a lack of joint exploration of the relationship between m7G methylation and immune status in osteosarcoma. Methods With the support of TARGET and GEO databases, we performed consensus clustering to characterize molecular subtypes based on m7G regulators in all osteosarcoma patients. The least absolute shrinkage and selection operator (LASSO) method, Cox regression, and receiver operating characteristic (ROC) curves were employed to construct and validate m7G-related prognostic features and derived risk scores. In addition, GSVA, ssGSEA, CIBERSORT, ESTIMATE, and gene set enrichment analysis were conducted to characterize biological pathways and immune landscapes. We explored the relationship between risk scores and drug sensitivity, immune checkpoints, and human leukocyte antigens by correlation analysis. Finally, the roles of EIF4E3 in cell function were verified through external experiments. Results Two molecular isoforms based on regulator genes were identified, which presented significant discrepancies in terms of survival and activated pathways. Moreover, the six m7G regulators most associated with prognosis in osteosarcoma patients were identified as independent predictors for the construction of prognostic signature. The model was well stabilized and outperformed traditional clinicopathological features to reliably predict 3-year (AUC = 0.787) and 5-year (AUC = 0.790) survival in osteosarcoma cohorts. Patients with increased risk scores had a poorer prognosis, higher tumor purity, lower checkpoint gene expression, and were in an immunosuppressive microenvironment. Furthermore, enhanced expression of EIF4E3 indicated a favorable prognosis and affected the biological behavior of osteosarcoma cells. Conclusions We identified six prognostic relevant m7G modulators that may provide valuable indicators for the estimation of overall survival and the corresponding immune landscape in patients with osteosarcoma.
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7
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Sharma S, Yang J, Favate J, Shah P, Kiledjian M. NADcapPro and circNC: methods for accurate profiling of NAD and non-canonical RNA caps in eukaryotes. Commun Biol 2023; 6:406. [PMID: 37055518 PMCID: PMC10101982 DOI: 10.1038/s42003-023-04774-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/28/2023] [Indexed: 04/15/2023] Open
Abstract
Accurate identification of NAD-capped RNAs is essential for delineating their generation and biological function. Previous transcriptome-wide methods used to classify NAD-capped RNAs in eukaryotes contain inherent limitations that have hindered the accurate identification of NAD caps from eukaryotic RNAs. In this study, we introduce two orthogonal methods to identify NAD-capped RNAs more precisely. The first, NADcapPro, uses copper-free click chemistry and the second is an intramolecular ligation-based RNA circularization, circNC. Together, these methods resolve the limitations of previous methods and allowed us to discover unforeseen features of NAD-capped RNAs in budding yeast. Contrary to previous reports, we find that 1) cellular NAD-RNAs can be full-length and polyadenylated transcripts, 2) transcription start sites for NAD-capped and canonical m7G-capped RNAs can be different, and 3) NAD caps can be added subsequent to transcription initiation. Moreover, we uncovered a dichotomy of NAD-RNAs in translation where they are detected with mitochondrial ribosomes but minimally on cytoplasmic ribosomes indicating their propensity to be translated in mitochondria.
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Affiliation(s)
- Sunny Sharma
- Department of Cell Biology and Neurosciences, Rutgers University, Piscataway, NJ, USA.
| | - Jun Yang
- Department of Cell Biology and Neurosciences, Rutgers University, Piscataway, NJ, USA
| | - John Favate
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
| | - Premal Shah
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
| | - Megerditch Kiledjian
- Department of Cell Biology and Neurosciences, Rutgers University, Piscataway, NJ, USA.
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8
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Wolfram-Schauerte M, Höfer K. NAD-capped RNAs - a redox cofactor meets RNA. Trends Biochem Sci 2023; 48:142-155. [PMID: 36068130 DOI: 10.1016/j.tibs.2022.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 01/25/2023]
Abstract
RNA modifications immensely expand the diversity of the transcriptome, thereby influencing the function, localization, and stability of RNA. One prominent example of an RNA modification is the eukaryotic cap located at the 5' terminus of mRNAs. Interestingly, the redox cofactor NAD can be incorporated into RNA by RNA polymerase in vitro. The existence of NAD-modified RNAs in vivo was confirmed using liquid chromatography and mass spectrometry (LC-MS). In the past few years novel technologies and methods have characterized NAD as a cap-like RNA structure and enabled the investigation of NAD-capped RNAs (NAD-RNAs) in a physiological context. We highlight the identification of NAD-RNAs as well as the regulation and functions of this epitranscriptomic mark in all domains of life.
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Affiliation(s)
| | - Katharina Höfer
- Max-Planck-Institute for Terrestrial Microbiology, Marburg, 35043, Hessen, Germany.
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9
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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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10
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Sharma S, Yang J, Doamekpor SK, Grudizen-Nogalska E, Tong L, Kiledjian M. Identification of a novel deFADding activity in human, yeast and bacterial 5' to 3' exoribonucleases. Nucleic Acids Res 2022; 50:8807-8817. [PMID: 35904778 PMCID: PMC9410882 DOI: 10.1093/nar/gkac617] [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: 03/31/2022] [Revised: 06/18/2022] [Accepted: 07/21/2022] [Indexed: 11/19/2022] Open
Abstract
Identification of metabolite caps including FAD on the 5' end of RNA has uncovered a previously unforeseen intersection between cellular metabolism and gene expression. To understand the function of FAD caps in cellular physiology, we characterised the proteins interacting with FAD caps in budding yeast. Here we demonstrate that highly conserved 5'-3' exoribonucleases, Xrn1 and Rat1, physically interact with the RNA 5' FAD cap and both possess FAD cap decapping (deFADding) activity and subsequently degrade the resulting RNA. Xrn1 deFADding activity was also evident in human cells indicating its evolutionary conservation. Furthermore, we report that the recently identified bacterial 5'-3' exoribonuclease RNase AM also possesses deFADding activity that can degrade FAD-capped RNAs in vitro and in Escherichia coli cells. To gain a molecular understanding of the deFADding reaction, an RNase AM crystal structure with three manganese ions coordinated by a sulfate molecule and the active site amino acids was generated that provided details underlying hydrolysis of the FAD cap. Our findings reveal a general propensity for 5'-3' exoribonucleases to hydrolyse and degrade RNAs with 5' end noncanonical caps in addition to their well characterized 5' monophosphate RNA substrates indicating an intrinsic property of 5'-3' exoribonucleases.
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Affiliation(s)
- Sunny Sharma
- Department of Cell Biology and Neurosciences, Rutgers, University, Piscataway, NJ 08854, USA
| | - Jun Yang
- Department of Cell Biology and Neurosciences, Rutgers, University, Piscataway, NJ 08854, USA
| | - Selom K Doamekpor
- Department Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Ewa Grudizen-Nogalska
- Department of Cell Biology and Neurosciences, Rutgers, University, Piscataway, NJ 08854, USA
| | - Liang Tong
- Department Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Megerditch Kiledjian
- Department of Cell Biology and Neurosciences, Rutgers, University, Piscataway, NJ 08854, USA
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11
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Depaix A, Grudzien-Nogalska E, Fedorczyk B, Kiledjian M, Jemielity J, Kowalska J. Preparation of RNAs with non-canonical 5' ends using novel di- and trinucleotide reagents for co-transcriptional capping. Front Mol Biosci 2022; 9:854170. [PMID: 36060251 PMCID: PMC9437278 DOI: 10.3389/fmolb.2022.854170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 07/06/2022] [Indexed: 12/04/2022] Open
Abstract
Many eukaryotic and some bacterial RNAs are modified at the 5' end by the addition of cap structures. In addition to the classic 7-methylguanosine 5' cap in eukaryotic mRNA, several non-canonical caps have recently been identified, including NAD-linked, FAD-linked, and UDP-glucose-linked RNAs. However, studies of the biochemical properties of these caps are impaired by the limited access to in vitro transcribed RNA probes of high quality, as the typical capping efficiencies with NAD or FAD dinucleotides achieved in the presence of T7 polymerase rarely exceed 50%, and pyrimidine derivatives are not incorporated because of promoter sequence limitations. To address this issue, we developed a series of di- and trinucleotide capping reagents and in vitro transcription conditions to provide straightforward access to unconventionally capped RNAs with improved 5'-end homogeneity. We show that because of the transcription start site flexibility of T7 polymerase, R1ppApG-type structures (where R1 is either nicotinamide riboside or riboflavin) are efficiently incorporated into RNA during transcription from dsDNA templates containing both φ 6.5 and φ 2.5 promoters and enable high capping efficiencies (∼90%). Moreover, uridine-initiated RNAs are accessible by transcription from templates containing the φ 6.5 promoter performed in the presence of R2ppUpG-type initiating nucleotides (where R2 is a sugar or phosphate moiety). We successfully employed this strategy to obtain several nucleotide-sugar-capped and uncapped RNAs. The capping reagents developed herein provide easy access to chemical probes to elucidate the biological roles of non-canonical RNA 5' capping.
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Affiliation(s)
- Anaïs Depaix
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Ewa Grudzien-Nogalska
- Department of Cell Biology and Neuroscience, Rutgers University, New York, NJ, United States
| | | | - Megerditch Kiledjian
- Department of Cell Biology and Neuroscience, Rutgers University, New York, NJ, United States
| | - Jacek Jemielity
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Joanna Kowalska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
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12
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Staphylococcus aureus Small RNAs Possess Dephospho-CoA 5′-Caps, but No CoAlation Marks. Noncoding RNA 2022; 8:ncrna8040046. [PMID: 35893229 PMCID: PMC9326634 DOI: 10.3390/ncrna8040046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/16/2022] Open
Abstract
Novel features of coenzyme A (CoA) and its precursor, 3′-dephospho-CoA (dpCoA), recently became evident. dpCoA was found to attach to 5′-ends of small ribonucleic acids (dpCoA-RNAs) in two bacterial species (Escherichia coli and Streptomyces venezuelae). Furthermore, CoA serves, in addition to its well-established coenzymatic roles, as a ubiquitous posttranslational protein modification (‘CoAlation’), thought to prevent the irreversible oxidation of cysteines. Here, we first identified and quantified dpCoA-RNAs in the small RNA fraction of the human pathogen Staphylococcus aureus, using a newly developed enzymatic assay. We found that the amount of dpCoA caps was similar to that of the other two bacteria. We furthermore tested the hypothesis that, in the environment of a cell, the free thiol of the dpCoA-RNAs, as well as other sulfur-containing RNA modifications, may be oxidized by disulfide bond formation, e.g., with CoA. While we could not find evidence for such an ‘RNA CoAlation’, we observed that CoA disulfide reductase, the enzyme responsible for reducing CoA homodisulfides in S. aureus, did efficiently reduce several synthetic dpCoA-RNA disulfides to dpCoA-RNAs in vitro. This activity may imply a role in reversing RNA CoAlation.
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13
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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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14
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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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15
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Vidya E, Duchaine TF. Eukaryotic mRNA Decapping Activation. Front Genet 2022; 13:832547. [PMID: 35401681 PMCID: PMC8984151 DOI: 10.3389/fgene.2022.832547] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
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
- *Correspondence: Thomas F. Duchaine,
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16
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Li L, Chen S, Li J, Rong G, Yang J, Li Y. Characterization of m6A-related lncRNA signature in neuroblastoma. Front Pediatr 2022; 10:927885. [PMID: 36324814 PMCID: PMC9618704 DOI: 10.3389/fped.2022.927885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/20/2022] [Indexed: 11/28/2022] Open
Abstract
N6-methyladenosine (m6A) constitutes one of the most common modifications in mRNA, rRNA, tRNA, microRNA, and long-chain noncoding RNA. The influence of modifications of m6A on the stability of RNA depends upon the expression of methyltransferase ("writer") and demethylase ("eraser") and m6A binding protein ("reader"). In this study, we identified a set of m6A-related lncRNA expression profiles in neuroblastoma (NBL) based on the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) program. Thereupon, we identified two subgroups of neuroblastoma (high-risk group and low-risk group) by applying consensus clustering to m6A RNA methylation regulators ("Readers,", "Writer," and "Erase"). Relative to the low-risk group, the high-risk group correlates with a poorer prognosis. Moreover, the present study also revealed that the high-risk group proves to be significantly positively enriched in the tumor-related signaling pathways, including the P53 signaling pathway, cell cycle, and DNA repair. This finding indicates that these molecular prognostic markers may also be potentially valuable in early diagnosis, which provides a new research direction for the study of molecular mechanisms underlying the development of NBL. In conclusion, this study constructed a new model of NBL prognosis based on m6a-associated lncRNAs. Ultimately, this model is helpful for stratification of prognosis and development of treatment strategies.
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Affiliation(s)
- Liming Li
- Department of Pediatric Surgery, GuiPing People's Hospital, Guangxi, China
| | - Sisi Chen
- Department of Pediatric Surgery, GuiPing People's Hospital, Guangxi, China
| | - Jianhong Li
- Department of Pediatric Surgery, GuiPing People's Hospital, Guangxi, China
| | - Guochou Rong
- Department of Pediatric Surgery, GuiPing People's Hospital, Guangxi, China
| | - Juchao Yang
- Department of Pediatric Surgery, GuiPing People's Hospital, Guangxi, China
| | - Yunquan Li
- Department of Pediatric Surgery, GuiPing People's Hospital, Guangxi, China
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17
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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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18
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Schauerte M, Pozhydaieva N, Höfer K. Shaping the Bacterial Epitranscriptome-5'-Terminal and Internal RNA Modifications. Adv Biol (Weinh) 2021; 5:e2100834. [PMID: 34121369 DOI: 10.1002/adbi.202100834] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/07/2021] [Indexed: 11/11/2022]
Abstract
All domains of life utilize a diverse set of modified ribonucleotides that can impact the sequence, structure, function, stability, and the fate of RNAs, as well as their interactions with other molecules. Today, more than 160 different RNA modifications are known that decorate the RNA at the 5'-terminus or internal RNA positions. The boost of next-generation sequencing technologies sets the foundation to identify and study the functional role of RNA modifications. The recent advances in the field of RNA modifications reveal a novel regulatory layer between RNA modifications and proteins, which is central to developing a novel concept called "epitranscriptomics." The majority of RNA modifications studies focus on the eukaryotic epitranscriptome. In contrast, RNA modifications in prokaryotes are poorly characterized. This review outlines the current knowledge of the prokaryotic epitranscriptome focusing on mRNA modifications. Here, it is described that several internal and 5'-terminal RNA modifications either present or likely present in prokaryotic mRNA. Thereby, the individual techniques to identify these epitranscriptomic modifications, their writers, readers and erasers, and their proposed functions are explored. Besides that, still unanswered questions in the field of prokaryotic epitranscriptomics are pointed out, and its future perspectives in the dawn of next-generation sequencing technologies are outlined.
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Affiliation(s)
- Maik Schauerte
- Max-Planck-Institute for terrestrial Microbiology, Marburg, Hessen, 35043, Germany
| | - Nadiia Pozhydaieva
- Max-Planck-Institute for terrestrial Microbiology, Marburg, Hessen, 35043, Germany
| | - Katharina Höfer
- Max-Planck-Institute for terrestrial Microbiology, Marburg, Hessen, 35043, Germany
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19
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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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20
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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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21
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Möhler M, Höfer K, Jäschke A. Synthesis of 5'-Thiamine-Capped RNA. Molecules 2020; 25:E5492. [PMID: 33255222 PMCID: PMC7727699 DOI: 10.3390/molecules25235492] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/20/2020] [Accepted: 11/21/2020] [Indexed: 01/05/2023] Open
Abstract
RNA 5'-modifications are known to extend the functional spectrum of ribonucleotides. In recent years, numerous non-canonical 5'-modifications, including adenosine-containing cofactors from the group of B vitamins, have been confirmed in all kingdoms of life. The structural component of thiamine adenosine triphosphate (thiamine-ATP), a vitamin B1 derivative found to accumulate in Escherichia coli and other organisms in response to metabolic stress conditions, suggests an analogous function as a 5'-modification of RNA. Here, we report the synthesis of thiamine adenosine dinucleotides and the preparation of pure 5'-thiamine-capped RNAs based on phosphorimidazolide chemistry. Furthermore, we present the incorporation of thiamine-ATP and thiamine adenosine diphosphate (thiamine-ADP) as 5'-caps of RNA by T7 RNA polymerase. Transcripts containing the thiamine modification were modified specifically with biotin via a combination of thiazole ring opening, nucleophilic substitution and copper-catalyzed azide-alkyne cycloaddition. The highlighted methods provide easy access to 5'-thiamine RNA, which may be applied in the development of thiamine-specific RNA capture protocols as well as the discovery and confirmation of 5'-thiamine-capped RNAs in various organisms.
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Affiliation(s)
| | | | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany; (M.M.); (K.H.)
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22
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Ferguson F, McLennan AG, Urbaniak MD, Jones NJ, Copeland NA. Re-evaluation of Diadenosine Tetraphosphate (Ap 4A) From a Stress Metabolite to Bona Fide Secondary Messenger. Front Mol Biosci 2020; 7:606807. [PMID: 33282915 PMCID: PMC7705103 DOI: 10.3389/fmolb.2020.606807] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/19/2020] [Indexed: 01/14/2023] Open
Abstract
Cellular homeostasis requires adaption to environmental stress. In response to various environmental and genotoxic stresses, all cells produce dinucleoside polyphosphates (NpnNs), the best studied of which is diadenosine tetraphosphate (Ap4A). Despite intensive investigation, the precise biological roles of these molecules have remained elusive. However, recent studies have elucidated distinct and specific signaling mechanisms for these nucleotides in prokaryotes and eukaryotes. This review summarizes these key discoveries and describes the mechanisms of Ap4A and Ap4N synthesis, the mediators of the cellular responses to increased intracellular levels of these molecules and the hydrolytic mechanisms required to maintain low levels in the absence of stress. The intracellular responses to dinucleotide accumulation are evaluated in the context of the "friend" and "foe" scenarios. The "friend (or alarmone) hypothesis" suggests that ApnN act as bona fide secondary messengers mediating responses to stress. In contrast, the "foe" hypothesis proposes that ApnN and other NpnN are produced by non-canonical enzymatic synthesis as a result of physiological and environmental stress in critically damaged cells but do not actively regulate mitigating signaling pathways. In addition, we will discuss potential target proteins, and critically assess new evidence supporting roles for ApnN in the regulation of gene expression, immune responses, DNA replication and DNA repair. The recent advances in the field have generated great interest as they have for the first time revealed some of the molecular mechanisms that mediate cellular responses to ApnN. Finally, areas for future research are discussed with possible but unproven roles for intracellular ApnN to encourage further research into the signaling networks that are regulated by these nucleotides.
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Affiliation(s)
- Freya Ferguson
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Materials Science Institute, Lancaster University, Lancaster, United Kingdom
| | - Alexander G McLennan
- Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Michael D Urbaniak
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Nigel J Jones
- Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Nikki A Copeland
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Materials Science Institute, Lancaster University, Lancaster, United Kingdom
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23
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Zhang Y, Kuster D, Schmidt T, Kirrmaier D, Nübel G, Ibberson D, Benes V, Hombauer H, Knop M, Jäschke A. Extensive 5'-surveillance guards against non-canonical NAD-caps of nuclear mRNAs in yeast. Nat Commun 2020; 11:5508. [PMID: 33139726 PMCID: PMC7606564 DOI: 10.1038/s41467-020-19326-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/24/2020] [Indexed: 12/16/2022] Open
Abstract
The ubiquitous redox coenzyme nicotinamide adenine dinucleotide (NAD) acts as a non-canonical cap structure on prokaryotic and eukaryotic ribonucleic acids. Here we find that in budding yeast, NAD-RNAs are abundant (>1400 species), short (<170 nt), and mostly correspond to mRNA 5′-ends. The modification percentage of transcripts is low (<5%). NAD incorporation occurs mainly during transcription initiation by RNA polymerase II, which uses distinct promoters with a YAAG core motif for this purpose. Most NAD-RNAs are 3′-truncated. At least three decapping enzymes, Rai1, Dxo1, and Npy1, guard against NAD-RNA at different cellular locations, targeting overlapping transcript populations. NAD-mRNAs are not translatable in vitro. Our work indicates that in budding yeast, most of the NAD incorporation into RNA seems to be disadvantageous to the cell, which has evolved a diverse surveillance machinery to prematurely terminate, decap and reject NAD-RNAs. NAD (nicotinamide adenine dinucleotide) acts as a non-canonical RNA cap structure in bacteria and eukaryotes. Here the authors demonstrate the whole landscape of budding yeast NAD-RNAs which are subject to diverse surveillance pathways, suggesting that NAD caps in budding yeast are mostly dysfunctional.
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Affiliation(s)
- Yaqing Zhang
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany
| | - David Kuster
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany
| | - Tobias Schmidt
- DNA Repair Mechanisms and Cancer, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Daniel Kirrmaier
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany.,Cell Morphogenesis and Signal Transduction, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Gabriele Nübel
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany
| | - David Ibberson
- Deep Sequencing Core Facility, CellNetworks, Heidelberg University, 69120, Heidelberg, Germany
| | - Vladimir Benes
- Genomics Core Facility, European Molecular Biology Laboratory (EMBL), 69117, Heidelberg, Germany
| | - Hans Hombauer
- DNA Repair Mechanisms and Cancer, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany.,Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany
| | - Michael Knop
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany.,Cell Morphogenesis and Signal Transduction, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany.
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Sharma S, Grudzien-Nogalska E, Hamilton K, Jiao X, Yang J, Tong L, Kiledjian M. Mammalian Nudix proteins cleave nucleotide metabolite caps on RNAs. Nucleic Acids Res 2020; 48:6788-6798. [PMID: 32432673 PMCID: PMC7337524 DOI: 10.1093/nar/gkaa402] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/01/2020] [Accepted: 05/05/2020] [Indexed: 12/12/2022] Open
Abstract
We recently reported the presence of nicotinamide adenine dinucleotide (NAD)-capped RNAs in mammalian cells and a role for DXO and the Nudix hydrolase Nudt12 in decapping NAD-capped RNAs (deNADding) in cells. Analysis of 5'caps has revealed that in addition to NAD, mammalian RNAs also contain other metabolite caps including flavin adenine dinucleotide (FAD) and dephosphoCoA (dpCoA). In the present study we systematically screened all mammalian Nudix proteins for their potential deNADing, FAD cap decapping (deFADding) and dpCoA cap decapping (deCoAping) activity. We demonstrate that Nudt16 is a novel deNADding enzyme in mammalian cells. Additionally, we identified seven Nudix proteins-Nudt2, Nudt7, Nudt8, Nudt12, Nudt15, Nudt16 and Nudt19, to possess deCoAping activity in vitro. Moreover, our screening revealed that both mammalian Nudt2 and Nudt16 hydrolyze FAD-capped RNAs in vitro with Nudt16 regulating levels of FAD-capped RNAs in cells. All decapping activities identified hydrolyze the metabolite cap substrate within the diphosphate linkage. Crystal structure of human Nudt16 in complex with FAD at 2.7 Å resolution provide molecular insights into the binding and metal-coordinated hydrolysis of FAD by Nudt16. In summary, our study identifies novel cellular deNADding and deFADding enzymes and establishes a foundation for the selective functionality of the Nudix decapping enzymes on non-canonical metabolite caps.
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Affiliation(s)
- Sunny Sharma
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Ewa Grudzien-Nogalska
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Keith Hamilton
- Department Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Xinfu Jiao
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Jun Yang
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Liang Tong
- Department Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Megerditch Kiledjian
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
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