1
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Liu S, Wang H, Li X, Zhang F, Lee JKJ, Li Z, Yu C, Hu JJ, Zhao X, Suematsu T, Alvarez-Cabrera AL, Liu Q, Zhang L, Huang L, Aphasizheva I, Aphasizhev R, Zhou ZH. Structural basis of gRNA stabilization and mRNA recognition in trypanosomal RNA editing. Science 2023; 381:eadg4725. [PMID: 37410820 DOI: 10.1126/science.adg4725] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/17/2023] [Indexed: 07/08/2023]
Abstract
In Trypanosoma brucei, the editosome, composed of RNA-editing substrate-binding complex (RESC) and RNA-editing catalytic complex (RECC), orchestrates guide RNA (gRNA)-programmed editing to recode cryptic mitochondrial transcripts into messenger RNAs (mRNAs). The mechanism of information transfer from gRNA to mRNA is unclear owing to a lack of high-resolution structures for these complexes. With cryo-electron microscopy and functional studies, we have captured gRNA-stabilizing RESC-A and gRNA-mRNA-binding RESC-B and RESC-C particles. RESC-A sequesters gRNA termini, thus promoting hairpin formation and blocking mRNA access. The conversion of RESC-A into RESC-B or -C unfolds gRNA and allows mRNA selection. The ensuing gRNA-mRNA duplex protrudes from RESC-B, likely exposing editing sites to RECC-catalyzed cleavage, uridine insertion or deletion, and ligation. Our work reveals a remodeling event facilitating gRNA-mRNA hybridization and assembly of a macromolecular substrate for the editosome's catalytic modality.
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Affiliation(s)
- Shiheng Liu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Hong Wang
- Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, MA, USA
| | - Xiaorun Li
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Fan Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Jane K J Lee
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Zihang Li
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Clinton Yu
- Department of Physiology and Biophysics, University of California, Irvine, CA, USA
| | - Jason J Hu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Xiaojing Zhao
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Takuma Suematsu
- Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, MA, USA
| | - Ana L Alvarez-Cabrera
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Qiushi Liu
- Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, MA, USA
| | - Liye Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- Shanghai Clinical Research and Trial Center, Shanghai 201210, China
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, CA, USA
| | - Inna Aphasizheva
- Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, MA, USA
| | - Ruslan Aphasizhev
- Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, MA, USA
- Department of Biochemistry, Boston University Medical Campus, Boston, MA, USA
| | - Z Hong Zhou
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
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2
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Malik D, Kobyłecki K, Krawczyk P, Poznański J, Jakielaszek A, Napiórkowska A, Dziembowski A, Tomecki R, Nowotny M. Structure and mechanism of CutA, RNA nucleotidyl transferase with an unusual preference for cytosine. Nucleic Acids Res 2020; 48:9387-9405. [PMID: 32785623 PMCID: PMC7498324 DOI: 10.1093/nar/gkaa647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/14/2020] [Accepted: 07/27/2020] [Indexed: 11/12/2022] Open
Abstract
Template-independent terminal ribonucleotide transferases (TENTs) catalyze the addition of nucleotide monophosphates to the 3′-end of RNA molecules regulating their fate. TENTs include poly(U) polymerases (PUPs) with a subgroup of 3′ CUCU-tagging enzymes, such as CutA in Aspergillus nidulans. CutA preferentially incorporates cytosines, processively polymerizes only adenosines and does not incorporate or extend guanosines. The basis of this peculiar specificity remains to be established. Here, we describe crystal structures of the catalytic core of CutA in complex with an incoming non-hydrolyzable CTP analog and an RNA with three adenosines, along with biochemical characterization of the enzyme. The binding of GTP or a primer with terminal guanosine is predicted to induce clashes between 2-NH2 of the guanine and protein, which would explain why CutA is unable to use these ligands as substrates. Processive adenosine polymerization likely results from the preferential binding of a primer ending with at least two adenosines. Intriguingly, we found that the affinities of CutA for the CTP and UTP are very similar and the structures did not reveal any apparent elements for specific NTP binding. Thus, the properties of CutA likely result from an interplay between several factors, which may include a conformational dynamic process of NTP recognition.
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Affiliation(s)
- Deepshikha Malik
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw 02-109, Poland
| | - Kamil Kobyłecki
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warsaw 02-106, Poland
| | - Paweł Krawczyk
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw 02-109, Poland
| | - Jarosław Poznański
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warsaw 02-106, Poland
| | - Aleksandra Jakielaszek
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw 02-109, Poland
| | - Agnieszka Napiórkowska
- Structural Biology Center, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw 02-109, Poland
| | - Andrzej Dziembowski
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw 02-109, Poland.,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, Warsaw 02-106, Poland
| | - Rafał Tomecki
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warsaw 02-106, Poland.,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, Warsaw 02-106, Poland
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw 02-109, Poland
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3
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Aphasizheva I, Alfonzo J, Carnes J, Cestari I, Cruz-Reyes J, Göringer HU, Hajduk S, Lukeš J, Madison-Antenucci S, Maslov DA, McDermott SM, Ochsenreiter T, Read LK, Salavati R, Schnaufer A, Schneider A, Simpson L, Stuart K, Yurchenko V, Zhou ZH, Zíková A, Zhang L, Zimmer S, Aphasizhev R. Lexis and Grammar of Mitochondrial RNA Processing in Trypanosomes. Trends Parasitol 2020; 36:337-355. [PMID: 32191849 PMCID: PMC7083771 DOI: 10.1016/j.pt.2020.01.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/19/2020] [Accepted: 01/22/2020] [Indexed: 12/15/2022]
Abstract
Trypanosoma brucei spp. cause African human and animal trypanosomiasis, a burden on health and economy in Africa. These hemoflagellates are distinguished by a kinetoplast nucleoid containing mitochondrial DNAs of two kinds: maxicircles encoding ribosomal RNAs (rRNAs) and proteins and minicircles bearing guide RNAs (gRNAs) for mRNA editing. All RNAs are produced by a phage-type RNA polymerase as 3' extended precursors, which undergo exonucleolytic trimming. Most pre-mRNAs proceed through 3' adenylation, uridine insertion/deletion editing, and 3' A/U-tailing. The rRNAs and gRNAs are 3' uridylated. Historically, RNA editing has attracted major research effort, and recently essential pre- and postediting processing events have been discovered. Here, we classify the key players that transform primary transcripts into mature molecules and regulate their function and turnover.
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Affiliation(s)
- Inna Aphasizheva
- Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, MA 02118, USA.
| | - Juan Alfonzo
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Jason Carnes
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA 98109, USA
| | - Igor Cestari
- Institute of Parasitology, McGill University, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, H9X3V9, Québec, Canada
| | - Jorge Cruz-Reyes
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - H Ulrich Göringer
- Department of Molecular Genetics, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Stephen Hajduk
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences and Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Susan Madison-Antenucci
- Parasitology Laboratory, Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Dmitri A Maslov
- Department of Molecular, Cell, and Systems Biology, University of California - Riverside, Riverside, CA 92521, USA
| | - Suzanne M McDermott
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA 98109, USA
| | - Torsten Ochsenreiter
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, Bern CH-3012, Switzerland
| | - Laurie K Read
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
| | - Reza Salavati
- Institute of Parasitology, McGill University, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, H9X3V9, Québec, Canada
| | - Achim Schnaufer
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Bern CH-3012, Switzerland
| | - Larry Simpson
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA90095, USA
| | - Kenneth Stuart
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA 98109, USA
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic; Martsinovsky Institute of Medical Parasitology, Sechenov University, Moscow, Russia
| | - Z Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA90095, USA
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences and Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Liye Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Sara Zimmer
- University of Minnesota Medical School, Duluth campus, Duluth, MN 55812, USA
| | - Ruslan Aphasizhev
- Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, MA 02118, USA
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4
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Kroupova A, Ivascu A, Reimão-Pinto MM, Ameres SL, Jinek M. Structural basis for acceptor RNA substrate selectivity of the 3' terminal uridylyl transferase Tailor. Nucleic Acids Res 2019; 47:1030-1042. [PMID: 30462292 PMCID: PMC6344859 DOI: 10.1093/nar/gky1164] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/12/2018] [Indexed: 11/16/2022] Open
Abstract
Non-templated 3′-uridylation of RNAs has emerged as an important mechanism for regulating the processing, stability and biological function of eukaryotic transcripts. In Drosophila, oligouridine tailing by the terminal uridylyl transferase (TUTase) Tailor of numerous RNAs induces their degradation by the exonuclease Dis3L2, which serves functional roles in RNA surveillance and mirtron RNA biogenesis. Tailor preferentially uridylates RNAs terminating in guanosine or uridine nucleotides but the structural basis underpinning its RNA substrate selectivity is unknown. Here, we report crystal structures of Tailor bound to a donor substrate analog or mono- and oligouridylated RNA products. These structures reveal specific amino acid residues involved in donor and acceptor substrate recognition, and complementary biochemical assays confirm the critical role of an active site arginine in conferring selectivity toward 3′-guanosine terminated RNAs. Notably, conservation of these active site features suggests that other eukaryotic TUTases, including mammalian TUT4 and TUT7, might exhibit similar, hitherto unknown, substrate selectivity. Together, these studies provide critical insights into the specificity of 3′-uridylation in eukaryotic post-transcriptional gene regulation.
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Affiliation(s)
- Alena Kroupova
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
| | - Anastasia Ivascu
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
| | - Madalena M Reimão-Pinto
- Institute of Molecular Biotechnology, IMBA, Vienna Biocenter Campus (VBC), Vienna 1030, Austria
| | - Stefan L Ameres
- Institute of Molecular Biotechnology, IMBA, Vienna Biocenter Campus (VBC), Vienna 1030, Austria
| | - Martin Jinek
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
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5
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De Almeida C, Scheer H, Zuber H, Gagliardi D. RNA uridylation: a key posttranscriptional modification shaping the coding and noncoding transcriptome. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 9. [PMID: 28984054 DOI: 10.1002/wrna.1440] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/03/2017] [Accepted: 08/07/2017] [Indexed: 12/27/2022]
Abstract
RNA uridylation is a potent and widespread posttranscriptional regulator of gene expression. RNA uridylation has been detected in a range of eukaryotes including trypanosomes, animals, plants, and fungi, but with the noticeable exception of budding yeast. Virtually all classes of eukaryotic RNAs can be uridylated and uridylation can also tag viral RNAs. The untemplated addition of a few uridines at the 3' end of a transcript can have a decisive impact on RNA's fate. In rare instances, uridylation is an intrinsic step in the maturation of noncoding RNAs like for the U6 spliceosomal RNA or mitochondrial guide RNAs in trypanosomes. Uridylation can also switch specific miRNA precursors from a degradative to a processing mode. This switch depends on the number of uridines added which is regulated by the cellular context. Yet, the typical consequence of uridylation on mature noncoding RNAs or their precursors is to accelerate decay. Importantly, mRNAs are also tagged by uridylation. In fact, the advent of novel high throughput sequencing protocols has recently revealed the pervasiveness of mRNA uridylation, from plants to humans. As for noncoding RNAs, the main function to date for mRNA uridylation is to promote degradation. Yet, additional roles begin to be ascribed to U-tailing such as the control of mRNA deadenylation, translation control and possibly storage. All these new findings illustrate that we are just beginning to appreciate the diversity of roles played by RNA uridylation and its full temporal and spatial implication in regulating gene expression. WIREs RNA 2018, 9:e1440. doi: 10.1002/wrna.1440 This article is categorized under: RNA Processing > 3' End Processing RNA Processing > RNA Editing and Modification RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms.
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Affiliation(s)
- Caroline De Almeida
- Institut de Biologie Moleculaire des Plantes (IBMP), CNRS, University of Strasbourg, Strasbourg, France
| | - Hélène Scheer
- Institut de Biologie Moleculaire des Plantes (IBMP), CNRS, University of Strasbourg, Strasbourg, France
| | - Hélène Zuber
- Institut de Biologie Moleculaire des Plantes (IBMP), CNRS, University of Strasbourg, Strasbourg, France
| | - Dominique Gagliardi
- Institut de Biologie Moleculaire des Plantes (IBMP), CNRS, University of Strasbourg, Strasbourg, France
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6
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Faehnle CR, Walleshauser J, Joshua-Tor L. Multi-domain utilization by TUT4 and TUT7 in control of let-7 biogenesis. Nat Struct Mol Biol 2017; 24:658-665. [PMID: 28671666 PMCID: PMC5542866 DOI: 10.1038/nsmb.3428] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 06/07/2017] [Indexed: 12/20/2022]
Abstract
The uridyl transferases TUT4 and TUT7 switch between two modes of activity that either promotes let-7 expression (monoU) or marks it for degradation (oligoU). Lin28 modulates the switch via recruitment of TUT4(7) to pre-let-7 in stem cells and human cancers. We found TUT4(7) utilize two multi-domain functional modules during the switch from mono- to oligoU. The catalytic module (CM) is essential for both activities, while the Lin28-interacting module (LIM) is indispensible for oligoU. The TUT7 CM structure trapped in the monoU state, revealed a duplex RNA binding pocket that orients group II pre-let-7 hairpins to position the 1-nt overhang favor monoU addition. Conversely, the switch to oligoU requires the ZK domain of Lin28 to drive the formation of a stable ternary complex between pre-let-7 and the inactive LIM. Finally, ZK2 of TUT4(7) aids oligoU addition by engaging the growing oligoU tail through uracil-specific interactions.
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Affiliation(s)
- Christopher R Faehnle
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.,Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Jack Walleshauser
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.,Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.,Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Leemor Joshua-Tor
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.,Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.,Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
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7
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Cheng KJ, Demir Ö, Amaro RE. A Comparative Study of the Structural Dynamics of Four Terminal Uridylyl Transferases. Genes (Basel) 2017. [PMID: 28632168 PMCID: PMC5485530 DOI: 10.3390/genes8060166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
African trypanosomiasis occurs in 36 countries in sub-Saharan Africa with 10,000 reported cases annually. No definitive remedy is currently available and if left untreated, the disease becomes fatal. Structural and biochemical studies of trypanosomal terminal uridylyl transferases (TUTases) demonstrated their functional role in extensive uridylate insertion/deletion of RNA. Trypanosoma brucei RNA Editing TUTase 1 (TbRET1) is involved in guide RNA 3’ end uridylation and maturation, while TbRET2 is responsible for U-insertion at RNA editing sites. Two additional TUTases called TbMEAT1 and TbTUT4 have also been reported to share similar function. TbRET1 and TbRET2 are essential enzymes for the parasite viability making them potential drug targets. For this study, we clustered molecular dynamics (MD) trajectories of four TUTases based on active site shape measured by Pocket Volume Measurer (POVME) program. Among the four TUTases, TbRET1 exhibited the largest average pocket volume, while TbMEAT1’s and TbTUT4’s active sites displayed the most flexibility. A side pocket was also identified within the active site in all TUTases with TbRET1 having the most pronounced. Our results indicate that TbRET1’s larger side pocket can be exploited to achieve selective inhibitor design as FTMap identifies it as a druggable pocket.
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Affiliation(s)
- Kevin J Cheng
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Özlem Demir
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Rommie E Amaro
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA.
- National Biomedical Computation Resource, University of California, San Diego, La Jolla, CA 92093, USA.
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8
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Chung CZ, Seidl LE, Mann MR, Heinemann IU. Tipping the balance of RNA stability by 3' editing of the transcriptome. Biochim Biophys Acta Gen Subj 2017; 1861:2971-2979. [PMID: 28483641 DOI: 10.1016/j.bbagen.2017.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/02/2017] [Indexed: 11/26/2022]
Abstract
BACKGROUND The regulation of active microRNAs (miRNAs) and maturation of messenger RNAs (mRNAs) that are competent for translation is a crucial point in the control of all cellular processes, with established roles in development and differentiation. Terminal nucleotidyltransferases (TNTases) are potent regulators of RNA metabolism. TNTases promote the addition of single or multiple nucleotides to an RNA transcript that can rapidly alter transcript stability. The well-known polyadenylation promotes transcript stability while the newly discovered but ubiquitious 3'-end polyuridylation marks RNA for degradation. Monoadenylation and uridylation are essential control mechanisms balancing mRNA and miRNA homeostasis. SCOPE OF REVIEW This review discusses the multiple functions of non-canonical TNTases, focusing on their substrate range, biological functions, and evolution. TNTases directly control mRNA and miRNA levels, with diverse roles in transcriptome stabilization, maturation, silencing, or degradation. We will summarize the current state of knowledge on non-canonical nucleotidyltransferases and their function in regulating miRNA and mRNA metabolism. We will review the discovery of uridylation as an RNA degradation pathway and discuss the evolution of nucleotidyltransferases along with their use in RNA labeling and future applications as therapeutic targets. MAJOR CONCLUSIONS The biochemically and evolutionarily highly related adenylyl- and uridylyltransferases play antagonizing roles in the cell. In general, RNA adenylation promotes stability, while uridylation marks RNA for degradation. Uridylyltransferases evolved from adenylyltransferases in multiple independent evolutionary events by the insertion of a histidine residue into the active site, altering nucleotide, but not RNA specificity. GENERAL SIGNIFICANCE Understanding the mechanisms regulating RNA stability in the cell and controlling the transcriptome is essential for efforts aiming to influence cellular fate. Selectively enhancing or reducing RNA stability allows for alterations in the transcriptome, proteome, and downstream cellular processes. Genetic, biochemical, and clinical data suggest TNTases are potent targets for chemotherapeutics and have been exploited for RNA labeling applications. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue.
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Affiliation(s)
- Christina Z Chung
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Lauren E Seidl
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Mitchell R Mann
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Ilka U Heinemann
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
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9
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Aphasizhev R, Suematsu T, Zhang L, Aphasizheva I. Constructive edge of uridylation-induced RNA degradation. RNA Biol 2016; 13:1078-1083. [PMID: 27715485 PMCID: PMC5100348 DOI: 10.1080/15476286.2016.1229736] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/06/2016] [Accepted: 08/24/2016] [Indexed: 12/18/2022] Open
Abstract
RNA uridylation is a significant transcriptome-shaping factor in protists, fungi, metazoans, and plants. The 3' U-additions are catalyzed by terminal uridyltransferases (TUTases), a diverse group of enzymes that along with non-canonical poly(A) polymerases form a distinct group in the superfamily of DNA polymerase β-like nucleotidyl transferases. Within and across studied organisms and subcellular compartments, TUTases differ in nucleotide triphosphate selectivity, interacting partners, and RNA targets. A general premise linking RNA uridylation to 3'-5' degradation received support from several studies of small RNAs and mRNA turnover. However, recent work on kinetoplastid protists typified by Trypanosoma brucei provides evidence that RNA uridylation may play a more nuanced role in generating functional small RNAs. In this pathogen's mitochondrion, most mRNAs are internally edited by U-insertions and deletions, and subjected to 3' adenylation/uridylation; guide RNAs (gRNAs) required for editing are U-tailed. The prominent role of uridylation in mitochondrial RNA metabolism stimulated identification of the first TUTase, RNA editing TUTase 1 (RET1). Here we discuss functional studies of mitochondrial uridylation in trypanosomes that have revealed an unorthodox pathway of small RNA biogenesis. The current model accentuates physical coupling of RET1 and 3'-5' RNase II/RNB-type exonuclease DSS1 within a stable complex termed the mitochondrial 3' processome (MPsome). In the confines of this complex, RET1 initially uridylates a long precursor to activate its 3'-5' degradation by DSS1, and then uridylates trimmed guide RNA to disengage the processing complex from the mature molecule. We also discuss a potential role of antisense transcription in the MPsome pausing at a fixed distance from gRNA's 5' end. This step likely defines the mature 3' end by enabling kinetic competition between TUTase and exonuclease activities.
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Affiliation(s)
- Ruslan Aphasizhev
- Department of Molecular and Cell Biology, Boston University School of Dental Medicine, Boston, MA, USA
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Takuma Suematsu
- Department of Molecular and Cell Biology, Boston University School of Dental Medicine, Boston, MA, USA
| | - Liye Zhang
- Section of Computational Biomedicine, Boston University School of Medicine, Boston, MA, USA
| | - Inna Aphasizheva
- Department of Molecular and Cell Biology, Boston University School of Dental Medicine, Boston, MA, USA
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10
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Rajappa-Titu L, Suematsu T, Munoz-Tello P, Long M, Demir Ö, Cheng KJ, Stagno JR, Luecke H, Amaro RE, Aphasizheva I, Aphasizhev R, Thore S. RNA Editing TUTase 1: structural foundation of substrate recognition, complex interactions and drug targeting. Nucleic Acids Res 2016; 44:10862-10878. [PMID: 27744351 PMCID: PMC5159558 DOI: 10.1093/nar/gkw917] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 09/27/2016] [Accepted: 10/04/2016] [Indexed: 11/13/2022] Open
Abstract
Terminal uridyltransferases (TUTases) execute 3′ RNA uridylation across protists, fungi, metazoan and plant species. Uridylation plays a particularly prominent role in RNA processing pathways of kinetoplastid protists typified by the causative agent of African sleeping sickness, Trypanosoma brucei. In mitochondria of this pathogen, most mRNAs are internally modified by U-insertion/deletion editing while guide RNAs and rRNAs are U-tailed. The founding member of TUTase family, RNA editing TUTase 1 (RET1), functions as a subunit of the 3′ processome in uridylation of gRNA precursors and mature guide RNAs. Along with KPAP1 poly(A) polymerase, RET1 also participates in mRNA translational activation. RET1 is divergent from human TUTases and is essential for parasite viability in the mammalian host and the insect vector. Given its robust in vitro activity, RET1 represents an attractive target for trypanocide development. Here, we report high-resolution crystal structures of the RET1 catalytic core alone and in complex with UTP analogs. These structures reveal a tight docking of the conserved nucleotidyl transferase bi-domain module with a RET1-specific C2H2 zinc finger and RNA recognition (RRM) domains. Furthermore, we define RET1 region required for incorporation into the 3′ processome, determinants for RNA binding, subunit oligomerization and processive UTP incorporation, and predict druggable pockets.
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Affiliation(s)
- Lional Rajappa-Titu
- Department of Molecular Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Takuma Suematsu
- Department of Molecular and Cell Biology, Boston University School of Dental Medicine, Boston, MA 02118, USA
| | - Paola Munoz-Tello
- Department of Molecular Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Marius Long
- Department of Molecular Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Özlem Demir
- Department of Chemistry & Biochemistry and the National Biomedical Computation Resource, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kevin J Cheng
- Department of Chemistry & Biochemistry and the National Biomedical Computation Resource, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jason R Stagno
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Hartmut Luecke
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Rommie E Amaro
- Department of Chemistry & Biochemistry and the National Biomedical Computation Resource, University of California, San Diego, La Jolla, CA 92093, USA
| | - Inna Aphasizheva
- Department of Molecular and Cell Biology, Boston University School of Dental Medicine, Boston, MA 02118, USA
| | - Ruslan Aphasizhev
- Department of Molecular and Cell Biology, Boston University School of Dental Medicine, Boston, MA 02118, USA .,Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Stéphane Thore
- Department of Molecular Biology, University of Geneva, 1211 Geneva, Switzerland .,INSERM, U1212, ARNA Laboratory, Bordeaux 33000, France.,CNRS UMR5320, ARNA Laboratory, Bordeaux 33000, France.,University of Bordeaux, ARNA Laboratory, Bordeaux 33000, France
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11
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Lapkouski M, Hällberg BM. Structure of mitochondrial poly(A) RNA polymerase reveals the structural basis for dimerization, ATP selectivity and the SPAX4 disease phenotype. Nucleic Acids Res 2015; 43:9065-75. [PMID: 26319014 PMCID: PMC4605311 DOI: 10.1093/nar/gkv861] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/14/2015] [Indexed: 01/23/2023] Open
Abstract
Polyadenylation, performed by poly(A) polymerases (PAPs), is a ubiquitous post-transcriptional modification that plays key roles in multiple aspects of RNA metabolism. Although cytoplasmic and nuclear PAPs have been studied extensively, the mechanism by which mitochondrial PAP (mtPAP) selects adenosine triphosphate over other nucleotides is unknown. Furthermore, mtPAP is unique because it acts as a dimer. However, mtPAP's dimerization requirement remains enigmatic. Here, we show the structural basis for mtPAP's nucleotide selectivity, dimerization and catalysis. Our structures reveal an intricate dimerization interface that features an RNA-recognition module formed through strand complementation. Further, we propose the structural basis for the N478D mutation that drastically reduces the length of poly(A) tails on mitochondrial mRNAs in patients with spastic ataxia 4 (SPAX4), a severe and progressive neurodegenerative disease.
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Affiliation(s)
- Mikalai Lapkouski
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden Röntgen-Ångström-Cluster, Karolinska Institutet Outstation, Centre for Structural Systems Biology, DESY-Campus, 22607 Hamburg, Germany
| | - B Martin Hällberg
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden Röntgen-Ångström-Cluster, Karolinska Institutet Outstation, Centre for Structural Systems Biology, DESY-Campus, 22607 Hamburg, Germany European Molecular Biology Laboratory, Hamburg Unit, 22607 Hamburg, Germany
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12
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Simpson L, Douglass SM, Lake JA, Pellegrini M, Li F. Comparison of the Mitochondrial Genomes and Steady State Transcriptomes of Two Strains of the Trypanosomatid Parasite, Leishmania tarentolae. PLoS Negl Trop Dis 2015. [PMID: 26204118 PMCID: PMC4512693 DOI: 10.1371/journal.pntd.0003841] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
U-insertion/deletion RNA editing is a post-transcriptional mitochondrial RNA modification phenomenon required for viability of trypanosomatid parasites. Small guide RNAs encoded mainly by the thousands of catenated minicircles contain the information for this editing. We analyzed by NGS technology the mitochondrial genomes and transcriptomes of two strains, the old lab UC strain and the recently isolated LEM125 strain. PacBio sequencing provided complete minicircle sequences which avoided the assembly problem of short reads caused by the conserved regions. Minicircles were identified by a characteristic size, the presence of three short conserved sequences, a region of inherently bent DNA and the presence of single gRNA genes at a fairly defined location. The LEM125 strain contained over 114 minicircles encoding different gRNAs and the UC strain only ~24 minicircles. Some LEM125 minicircles contained no identifiable gRNAs. Approximate copy numbers of the different minicircle classes in the network were determined by the number of PacBio CCS reads that assembled to each class. Mitochondrial RNA libraries from both strains were mapped against the minicircle and maxicircle sequences. Small RNA reads mapped to the putative gRNA genes but also to multiple regions outside the genes on both strands and large RNA reads mapped in many cases over almost the entire minicircle on both strands. These data suggest that minicircle transcription is complete and bidirectional, with 3’ processing yielding the mature gRNAs. Steady state RNAs in varying abundances are derived from all maxicircle genes, including portions of the repetitive divergent region. The relative extents of editing in both strains correlated with the presence of a cascade of cognate gRNAs. These data should provide the foundation for a deeper understanding of this dynamic genetic system as well as the evolutionary variation of editing in different strains. U-insertion/deletion RNA editing is a unique post-transcriptional mRNA modification process that occurs in trypanosomatid parasites and is required for viability. The participation of guide RNAs which are transcribed from the thousands of catenated minicircles in determining the precise sites and number of U’s inserted and deleted to create translatable mRNAs is novel and significant in terms of the recently realized importance of small RNAs in biology. This study contributes the necessary bioinformatics foundation for a deeper understanding of this important genetic system in molecular detail using a model trypanosomatid, Leishmania tarentolae. We used Next Generation Sequencing methods to determine the complete maxicircle and minicircle genomes and to map maxicircle pre-edited and edited transcripts and minicircle transcripts. The transcription of minicircle-encoded guide RNAs was confirmed and novel information about minicircle gene expression was obtained. The biological context involved a comparison of two strains of the parasites, one recently isolated and having an intact mitochondrial genetic system and the other an old lab strain that has developed a partially defective mitochondrial genome. The data are important for an understanding of the mitochondrial genomic complexity and expression of this dynamic genetic system.
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Affiliation(s)
- Larry Simpson
- Department of Microbiology, Immunology and Molecular Genetics, Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| | - Stephen M. Douglass
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - James A. Lake
- Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Matteo Pellegrini
- Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Feng Li
- Dental Research Institute, School of Dentistry, University of California, Los Angeles, Los Angeles, California, United States of America
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13
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Polyuridylation in Eukaryotes: A 3'-End Modification Regulating RNA Life. BIOMED RESEARCH INTERNATIONAL 2015; 2015:968127. [PMID: 26078976 PMCID: PMC4442281 DOI: 10.1155/2015/968127] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/23/2015] [Accepted: 04/15/2015] [Indexed: 12/22/2022]
Abstract
In eukaryotes, mRNA polyadenylation is a well-known modification that is essential for many aspects of the protein-coding RNAs life cycle. However, modification of the 3′ terminal nucleotide within various RNA molecules is a general and conserved process that broadly modulates RNA function in all kingdoms of life. Numerous types of modifications have been characterized, which are generally specific for a given type of RNA such as the CCA addition found in tRNAs. In recent years, the addition of nontemplated uridine nucleotides or uridylation has been shown to occur in various types of RNA molecules and in various cellular compartments with significantly different outcomes. Indeed, uridylation is able to alter RNA half-life both in positive and in negative ways, highlighting the importance of the enzymes in charge of performing this modification. The present review aims at summarizing the current knowledge on the various processes leading to RNA 3′-end uridylation and on their potential impacts in various diseases.
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14
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Yates LA, Durrant BP, Barber M, Harlos K, Fleurdépine S, Norbury CJ, Gilbert RJC. Improved crystallization and diffraction of caffeine-induced death suppressor protein 1 (Cid1). ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2015; 71:346-53. [PMID: 25760713 PMCID: PMC4356314 DOI: 10.1107/s2053230x15001351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 01/21/2015] [Indexed: 11/25/2022]
Abstract
The use of truncation and RNA-binding mutations of caffeine induced death suppressor protein 1 (Cid1) as a means to enhance crystallogenesis leading to an improvement of X-ray diffraction resolution by 1.5 Å is reported. The post-transcriptional addition of uridines to the 3′-end of RNAs is an important regulatory process that is critical for coding and noncoding RNA stability. In fission yeast and metazoans this untemplated 3′-uridylylation is catalysed by a single family of terminal uridylyltransferases (TUTs) whose members are adapted to specific RNA targets. In Schizosaccharomyces pombe the TUT Cid1 is responsible for the uridylylation of polyadenylated mRNAs, targeting them for destruction. In metazoans, the Cid1 orthologues ZCCHC6 and ZCCHC11 uridylate histone mRNAs, targeting them for degradation, but also uridylate microRNAs, altering their maturation. Cid1 has been studied as a model TUT that has provided insights into the larger and more complex metazoan enzyme system. In this paper, two strategies are described that led to improvements both in the crystallogenesis of Cid1 and in the resolution of diffraction by ∼1.5 Å. These advances have allowed high-resolution crystallographic studies of this TUT system to be initiated.
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Affiliation(s)
- Luke A Yates
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
| | - Benjamin P Durrant
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
| | - Michael Barber
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
| | - Sophie Fleurdépine
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
| | - Chris J Norbury
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
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15
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Yates LA, Durrant BP, Fleurdépine S, Harlos K, Norbury CJ, Gilbert RJC. Structural plasticity of Cid1 provides a basis for its distributive RNA terminal uridylyl transferase activity. Nucleic Acids Res 2015; 43:2968-79. [PMID: 25712096 PMCID: PMC4357723 DOI: 10.1093/nar/gkv122] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Terminal uridylyl transferases (TUTs) are responsible for the post-transcriptional addition of uridyl residues to RNA 3′ ends, leading in some cases to altered stability. The Schizosaccharomyces pombe TUT Cid1 is a model enzyme that has been characterized structurally at moderate resolution and provides insights into the larger and more complex mammalian TUTs, ZCCHC6 and ZCCHC11. Here, we report a higher resolution (1.74 Å) crystal structure of Cid1 that provides detailed evidence for uracil selection via the dynamic flipping of a single histidine residue. We also describe a novel closed conformation of the enzyme that may represent an intermediate stage in a proposed product ejection mechanism. The structural insights gained, combined with normal mode analysis and biochemical studies, demonstrate that the plasticity of Cid1, particularly about a hinge region (N164–N165), is essential for catalytic activity, and provide an explanation for its distributive uridylyl transferase activity. We propose a model clarifying observed differences between the in vitro apparently processive activity and in vivo distributive monouridylylation activity of Cid1. We suggest that modulating the flexibility of such enzymes—for example by the binding of protein co-factors—may allow them alternatively to add single or multiple uridyl residues to the 3′ termini of RNA molecules.
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Affiliation(s)
- Luke A Yates
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Benjamin P Durrant
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Sophie Fleurdépine
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Chris J Norbury
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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16
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Munoz-Tello P, Gabus C, Thore S. A critical switch in the enzymatic properties of the Cid1 protein deciphered from its product-bound crystal structure. Nucleic Acids Res 2013; 42:3372-80. [PMID: 24322298 PMCID: PMC3950679 DOI: 10.1093/nar/gkt1278] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The addition of uridine nucleotide by the poly(U) polymerase (PUP) enzymes has a demonstrated impact on various classes of RNAs such as microRNAs (miRNAs), histone-encoding RNAs and messenger RNAs. Cid1 protein is a member of the PUP family. We solved the crystal structure of Cid1 in complex with non-hydrolyzable UMPNPP and a short dinucleotide compound ApU. These structures revealed new residues involved in substrate/product stabilization. In particular, one of the three catalytic aspartate residues explains the RNA dependence of its PUP activity. Moreover, other residues such as residue N165 or the β-trapdoor are shown to be critical for Cid1 activity. We finally suggest that the length and sequence of Cid1 substrate RNA influence the balance between Cid1's processive and distributive activities. We propose that particular processes regulated by PUPs require the enzymes to switch between the two types of activity as shown for the miRNA biogenesis where PUPs can either promote DICER cleavage via short U-tail or trigger miRNA degradation by adding longer poly(U) tail. The enzymatic properties of these enzymes may be critical for determining their particular function in vivo.
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Affiliation(s)
- Paola Munoz-Tello
- Department of Molecular Biology, University of Geneva, Geneva, 1211, Switzerland
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17
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Thornton JE, Chang HM, Piskounova E, Gregory RI. Lin28-mediated control of let-7 microRNA expression by alternative TUTases Zcchc11 (TUT4) and Zcchc6 (TUT7). RNA (NEW YORK, N.Y.) 2012; 18:1875-85. [PMID: 22898984 PMCID: PMC3446710 DOI: 10.1261/rna.034538.112] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The pluripotency factor Lin28 recruits a 3' terminal uridylyl transferase (TUTase) to selectively block let-7 microRNA biogenesis in undifferentiated cells. Zcchc11 (TUTase4/TUT4) was previously identified as an enzyme responsible for Lin28-mediated pre-let-7 uridylation and control of let-7 expression. Here we investigate the protein and RNA determinants for this interaction. Biochemical dissection and reconstitution assays reveal the TUTase domains necessary and sufficient for Lin28-enhanced pre-let-7 uridylation. A single C2H2-type zinc finger domain of Zcchc11 was found to be responsible for the functional interaction with Lin28. We identify Zcchc6 (TUTase7) as an alternative TUTase that functions with Lin28 in vitro, and accordingly, we find Zcchc11 and Zcchc6 redundantly control let-7 biogenesis in embryonic stem cells. Our study indicates that Lin28 uses two different TUTases to control let-7 expression and has important implications for stem cell biology as well as cancer.
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Affiliation(s)
- James E. Thornton
- Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Harvard Stem Cell Institute, Boston, Massachusetts 02115, USA
| | - Hao-Ming Chang
- Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Harvard Stem Cell Institute, Boston, Massachusetts 02115, USA
| | - Elena Piskounova
- Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Harvard Stem Cell Institute, Boston, Massachusetts 02115, USA
| | - Richard I. Gregory
- Stem Cell Program, Boston Children's Hospital, Boston, Massachusetts 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Harvard Stem Cell Institute, Boston, Massachusetts 02115, USA
- Corresponding authorE-mail
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18
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Chang JH, Tong L. Mitochondrial poly(A) polymerase and polyadenylation. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1819:992-7. [PMID: 22172994 PMCID: PMC3307840 DOI: 10.1016/j.bbagrm.2011.10.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/25/2011] [Accepted: 10/27/2011] [Indexed: 01/22/2023]
Abstract
Polyadenylation of mitochondrial RNAs in higher eukaryotic organisms have diverse effects on their function and metabolism. Polyadenylation completes the UAA stop codon of a majority of mitochondrial mRNAs in mammals, regulates the translation of the mRNAs, and has diverse effects on their stability. In contrast, polyadenylation of most mitochondrial mRNAs in plants leads to their degradation, consistent with the bacterial origin of this organelle. PAPD1 (mtPAP, TUTase1), a noncanonical poly(A) polymerase (ncPAP), is responsible for producing the poly(A) tails in mammalian mitochondria. The crystal structure of human PAPD1 was reported recently, offering molecular insights into its catalysis. This article is part of a Special Issue entitled: Mitochondrial Gene Expression.
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Affiliation(s)
- Jeong Ho Chang
- Department of Biological Sciences, Columbia University, New York, NY10027, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY10027, USA
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19
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Lunde BM, Magler I, Meinhart A. Crystal structures of the Cid1 poly (U) polymerase reveal the mechanism for UTP selectivity. Nucleic Acids Res 2012; 40:9815-24. [PMID: 22885303 PMCID: PMC3479196 DOI: 10.1093/nar/gks740] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Polyuridylation is emerging as a ubiquitous post-translational modification with important roles in multiple aspects of RNA metabolism. These poly (U) tails are added by poly (U) polymerases with homology to poly (A) polymerases; nevertheless, the selection for UTP over ATP remains enigmatic. We report the structures of poly (U) polymerase Cid1 from Schizoscaccharomyces pombe alone and in complex with UTP, CTP, GTP and 3′-dATP. These structures reveal that each of the 4 nt can be accommodated at the active site; however, differences exist that suggest how the polymerase selects UTP over the other nucleotides. Furthermore, we find that Cid1 shares a number of common UTP recognition features with the kinetoplastid terminal uridyltransferases. Kinetic analysis of Cid1’s activity for its preferred substrates, UTP and ATP, reveal a clear preference for UTP over ATP. Ultimately, we show that a single histidine in the active site plays a pivotal role for poly (U) activity. Notably, this residue is typically replaced by an asparagine residue in Cid1-family poly (A) polymerases. By mutating this histidine to an asparagine residue in Cid1, we diminished Cid1’s activity for UTP addition and improved ATP incorporation, supporting that this residue is important for UTP selectivity.
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Affiliation(s)
- Bradley M Lunde
- Department of Biomolecular Mechanisms, Max-Planck-Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
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20
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Wolkowicz UM, Cook AG. NF45 dimerizes with NF90, Zfr and SPNR via a conserved domain that has a nucleotidyltransferase fold. Nucleic Acids Res 2012; 40:9356-68. [PMID: 22833610 PMCID: PMC3467086 DOI: 10.1093/nar/gks696] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Nuclear factors NF90 and NF45 form a complex involved in a variety of cellular processes and are thought to affect gene expression both at the transcriptional and translational level. In addition, this complex affects the replication of several viruses through direct interactions with viral RNA. NF90 and NF45 dimerize through their common 'DZF' domain (domain associated with zinc fingers). NF90 has additional double-stranded RNA-binding domains that likely mediate its association with target RNAs. We present the crystal structure of the NF90/NF45 dimerization complex at 1.9-Å resolution. The DZF domain shows structural similarity to the template-free nucleotidyltransferase family of RNA modifying enzymes. However, both NF90 and NF45 have lost critical catalytic residues during evolution and are therefore not functional enzymes. Residues on NF90 that make up its interface with NF45 are conserved in two related proteins, spermatid perinuclear RNA-binding protein (SPNR) and zinc-finger RNA-binding protein (Zfr). Using a co-immunoprecipitation assay and site-specific mutants, we demonstrate that NF45 is also able to recognize SPNR and Zfr through the same binding interface, revealing that NF45 is able to form a variety of cellular complexes with other DZF-domain proteins.
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Affiliation(s)
- Urszula M Wolkowicz
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Edinburgh, Midlothian EH9 3JR, UK
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21
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Munoz-Tello P, Gabus C, Thore S. Functional implications from the Cid1 poly(U) polymerase crystal structure. Structure 2012; 20:977-86. [PMID: 22608966 DOI: 10.1016/j.str.2012.04.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/17/2012] [Accepted: 04/17/2012] [Indexed: 01/08/2023]
Abstract
In eukaryotes, mRNA degradation begins with poly(A) tail removal, followed by decapping, and the mRNA body is degraded by exonucleases. In recent years, the major influence of 3'-end uridylation as a regulatory step within several RNA degradation pathways has generated significant attention toward the responsible enzymes, which are called poly(U) polymerases (PUPs). We determined the atomic structure of the Cid1 protein, the founding member of the PUP family, in its UTP-bound form, allowing unambiguous positioning of the UTP molecule. Our data also suggest that the RNA substrate accommodation and product translocation by the Cid1 protein rely on local and global movements of the enzyme. Supplemented by point mutations, the atomic model is used to propose a catalytic cycle. Our study underlines the Cid1 RNA binding properties, a feature with critical implications for miRNAs, histone mRNAs, and, more generally, cellular RNA degradation.
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Affiliation(s)
- Paola Munoz-Tello
- Department of Molecular Biology, University of Geneva, 30 Quai Ernest Ansermet, Geneva 1211, Switzerland
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22
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Aphasizhev R, Aphasizheva I. Uridine insertion/deletion editing in trypanosomes: a playground for RNA-guided information transfer. WILEY INTERDISCIPLINARY REVIEWS. RNA 2011; 2:669-85. [PMID: 21823228 PMCID: PMC3154072 DOI: 10.1002/wrna.82] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
RNA editing is a collective term referring to enzymatic processes that change RNA sequence apart from splicing, 5' capping or 3' extension. In this article, we focus on uridine insertion/deletion mRNA editing found exclusively in mitochondria of kinetoplastid protists. This type of editing corrects frameshifts, introduces start and stops codons, and often adds much of the coding sequence to create an open reading frame. The mitochondrial genome of trypanosomatids, the most extensively studied clade within the order Kinetoplastida, is composed of ∼50 maxicircles with limited coding capacity and thousands of minicircles. To produce functional mRNAs, a multitude of nuclear-encoded factors mediate interactions of maxicircle-encoded pre-mRNAs with a vast repertoire of minicircle-encoded guide RNAs. Editing reactions of mRNA cleavage, U-insertions or U-deletions, and ligation are catalyzed by the RNA editing core complex (RECC, the 20S editosome) while each step of this enzymatic cascade is directed by guide RNAs. These 50-60 nucleotide (nt) molecules are 3' uridylated by RET1 TUTase and stabilized via association with the gRNA binding complex (GRBC). Remarkably, the information transfer between maxicircle and minicircle transcriptomes does not rely on template-dependent polymerization of nucleic acids. Instead, intrinsic substrate specificities of key enzymes are largely responsible for the fidelity of editing. Conversely, the efficiency of editing is enhanced by assembling enzymes and RNA binding proteins into stable multiprotein complexes. WIREs RNA 2011 2 669-685 DOI: 10.1002/wrna.82 For further resources related to this article, please visit the WIREs website.
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MESH Headings
- Endonucleases/chemistry
- Endonucleases/genetics
- Endonucleases/metabolism
- Models, Biological
- Models, Molecular
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
- RNA Editing/genetics
- RNA Editing/physiology
- RNA Helicases/chemistry
- RNA Helicases/genetics
- RNA Helicases/metabolism
- RNA, Guide, Kinetoplastida/genetics
- RNA, Guide, Kinetoplastida/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Protozoan/chemistry
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Trypanosoma/genetics
- Trypanosoma/metabolism
- Uridine/chemistry
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Affiliation(s)
- Ruslan Aphasizhev
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, USA.
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Aphasizhev R, Aphasizheva I. Mitochondrial RNA processing in trypanosomes. Res Microbiol 2011; 162:655-63. [PMID: 21596134 DOI: 10.1016/j.resmic.2011.04.015] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 04/04/2011] [Indexed: 01/20/2023]
Abstract
The mitochondrial genome of trypanosomes is composed of ∼50 maxicircles and thousands of minicircles. Maxi-(∼25 kb) and mini-(∼1 kb)circles are catenated and packed into a dense structure called a kinetoplast. Both types of circular DNA are transcribed by a phage-like RNA polymerase: maxicircles yield multicistronic rRNA and mRNA precursors, while guide RNA (gRNA) precursors are produced from minicircles. To function in mitochondrial translation, pre-mRNAs must undergo a nucleolytic processing and 3' modifications, and often uridine insertion/deletion editing. gRNAs, which represent short (50-60 nt) RNAs directing editing reactions, are produced by 3' nucleolytic processing of a much longer precursor followed by 3' uridylation. Ribosomal RNAs are excised from precursors and their 3' ends are also trimmed and uridylated. All tRNAs are imported from the cytoplasm and some are further modified and edited in the mitochondrial matrix. Historically, the fascinating phenomenon of RNA editing has been extensively studied as an isolated pathway in which nuclear-encoded proteins mediate interactions of maxi- and minicircle transcripts to create open reading frames. However, recent studies unraveled a highly integrated network of mitochondrial genome expression including critical pre- and post-editing 3' mRNA processing, and gRNA and rRNA maturation steps. Here we focus on RNA 3' adenylation and uridylation as processes essential for biogenesis, stability and functioning of mitochondrial RNAs.
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Affiliation(s)
- Ruslan Aphasizhev
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, B240 Medical Sciences I, Irvine, CA 92697, USA.
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