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Yeter-Alat H, Belgareh-Touzé N, Le Saux A, Huvelle E, Mokdadi M, Banroques J, Tanner NK. The RNA Helicase Ded1 from Yeast Is Associated with the Signal Recognition Particle and Is Regulated by SRP21. Molecules 2024; 29:2944. [PMID: 38931009 PMCID: PMC11206880 DOI: 10.3390/molecules29122944] [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: 05/22/2024] [Revised: 06/12/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
The DEAD-box RNA helicase Ded1 is an essential yeast protein involved in translation initiation that belongs to the DDX3 subfamily. The purified Ded1 protein is an ATP-dependent RNA-binding protein and an RNA-dependent ATPase, but it was previously found to lack substrate specificity and enzymatic regulation. Here we demonstrate through yeast genetics, yeast extract pull-down experiments, in situ localization, and in vitro biochemical approaches that Ded1 is associated with, and regulated by, the signal recognition particle (SRP), which is a universally conserved ribonucleoprotein complex required for the co-translational translocation of polypeptides into the endoplasmic reticulum lumen and membrane. Ded1 is physically associated with SRP components in vivo and in vitro. Ded1 is genetically linked with SRP proteins. Finally, the enzymatic activity of Ded1 is inhibited by SRP21 in the presence of SCR1 RNA. We propose a model where Ded1 actively participates in the translocation of proteins during translation. Our results provide a new understanding of the role of Ded1 during translation.
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Affiliation(s)
- Hilal Yeter-Alat
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, 13 rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (A.L.S.); (E.H.); (M.M.); (J.B.)
- Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, 75005 Paris, France
| | - Naïma Belgareh-Touzé
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, UMR8226 CNRS, Sorbonne Université, 13 rue Pierre et Marie Curie, 75005 Paris, France;
| | - Agnès Le Saux
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, 13 rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (A.L.S.); (E.H.); (M.M.); (J.B.)
- Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, 75005 Paris, France
| | - Emmeline Huvelle
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, 13 rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (A.L.S.); (E.H.); (M.M.); (J.B.)
- Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, 75005 Paris, France
| | - Molka Mokdadi
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, 13 rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (A.L.S.); (E.H.); (M.M.); (J.B.)
- Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, 75005 Paris, France
- Laboratory of Molecular Epidemiology and Experimental Pathology, LR16IPT04, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis 1002, Tunisia
- Institut National des Sciences Appliquées et Technologies, Université de Carthage, Tunis 1080, Tunisia
| | - Josette Banroques
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, 13 rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (A.L.S.); (E.H.); (M.M.); (J.B.)
- Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, 75005 Paris, France
| | - N. Kyle Tanner
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, 13 rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (A.L.S.); (E.H.); (M.M.); (J.B.)
- Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, 75005 Paris, France
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2
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Goldstein SI, Fan AC, Wang Z, Naineni SK, Lengqvist J, Chernobrovkin A, Garcia-Gutierrez SB, Cencic R, Patel K, Huang S, Brown LE, Emili A, Porco JA. Proteomic Discovery of RNA-Protein Molecular Clamps Using a Thermal Shift Assay with ATP and RNA (TSAR). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.19.590252. [PMID: 38659867 PMCID: PMC11042367 DOI: 10.1101/2024.04.19.590252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Uncompetitive inhibition is an effective strategy for suppressing dysregulated enzymes and their substrates, but discovery of suitable ligands depends on often-unavailable structural knowledge and serendipity. Hence, despite surging interest in mass spectrometry-based target identification, proteomic studies of substrate-dependent target engagement remain sparse. Herein, we describe the Thermal Shift Assay with ATP and RNA (TSAR) as a template for proteome-wide discovery of substrate-dependent ligand binding. Using proteomic thermal shift assays, we show that simple biochemical additives can facilitate detection of target engagement in native cell lysates. We apply our approach to rocaglates, a family of molecules that specifically clamp RNA to eukaryotic translation initiation factor 4A (eIF4A), DEAD-box helicase 3X (DDX3X), and potentially other members of the DEAD-box (DDX) family of RNA helicases. To identify unexpected interactions, we optimized a target class-specific thermal denaturation window and evaluated ATP analog and RNA probe dependencies for key rocaglate-DDX interactions. We report novel DDX targets of the rocaglate clamping spectrum, confirm that DDX3X is a common target of several widely studied analogs, and provide structural insights into divergent DDX3X affinities between synthetic rocaglates. We independently validate novel targets of high-profile rocaglates, including the clinical candidate Zotatifin (eFT226), using limited proteolysis-mass spectrometry and fluorescence polarization experiments. Taken together, our study provides a model for screening uncompetitive inhibitors using a systematic chemical-proteomics approach to uncover actionable DDX targets, clearing a path towards characterization of novel molecular clamps and associated RNA helicase targets.
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Affiliation(s)
- Stanley I. Goldstein
- BU Target Discovery Laboratory (BU-TDL), Boston University, Boston, MA, USA
- Department of Chemistry, Boston University, Boston, MA, USA
- Department of Pharmacology, Physiology, and Biophysics, Boston University, Boston, MA, USA
| | - Alice C. Fan
- BU Target Discovery Laboratory (BU-TDL), Boston University, Boston, MA, USA
- Department of Chemistry, Boston University, Boston, MA, USA
| | - Zihao Wang
- Department of Chemistry, Boston University, Boston, MA, USA
| | - Sai K. Naineni
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | | | | | | | - Regina Cencic
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Kesha Patel
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Sidong Huang
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | | | - Andrew Emili
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA
| | - John A. Porco
- BU Target Discovery Laboratory (BU-TDL), Boston University, Boston, MA, USA
- Department of Chemistry, Boston University, Boston, MA, USA
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3
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Cruz VE, Weirich CS, Peddada N, Erzberger JP. The DEAD-box ATPase Dbp10/DDX54 initiates peptidyl transferase center formation during 60S ribosome biogenesis. Nat Commun 2024; 15:3296. [PMID: 38632236 PMCID: PMC11024185 DOI: 10.1038/s41467-024-47616-7] [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: 12/12/2023] [Accepted: 04/04/2024] [Indexed: 04/19/2024] Open
Abstract
DEAD-box ATPases play crucial roles in guiding rRNA restructuring events during the biogenesis of large (60S) ribosomal subunits, but their precise molecular functions are currently unknown. In this study, we present cryo-EM reconstructions of nucleolar pre-60S intermediates that reveal an unexpected, alternate secondary structure within the nascent peptidyl-transferase-center (PTC). Our analysis of three sequential nucleolar pre-60S intermediates reveals that the DEAD-box ATPase Dbp10/DDX54 remodels this alternate base pairing and enables the formation of the rRNA junction that anchors the mature form of the universally conserved PTC A-loop. Post-catalysis, Dbp10 captures rRNA helix H61, initiating the concerted exchange of biogenesis factors during late nucleolar 60S maturation. Our findings show that Dbp10 activity is essential for the formation of the ribosome active site and reveal how this function is integrated with subsequent assembly steps to drive the biogenesis of the large ribosomal subunit.
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Affiliation(s)
- Victor E Cruz
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
- O'Donnell Brain Institute/CAND, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Christine S Weirich
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Nagesh Peddada
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
- Center for the Genetics of Host Defense, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Jan P Erzberger
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
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4
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Cruz VE, Weirich CS, Peddada N, Erzberger JP. The DEAD-box ATPase Dbp10/DDX54 initiates peptidyl transferase center formation during 60S ribosome biogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.01.565222. [PMID: 37961218 PMCID: PMC10635065 DOI: 10.1101/2023.11.01.565222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
DEAD-box ATPases play crucial roles in guiding rRNA restructuring events during the biogenesis of large (60S) ribosomal subunits, but their precise molecular functions are currently unknown. In this study, we present cryo-EM reconstructions of nucleolar pre-60S intermediates that reveal an unexpected, alternate secondary structure within the nascent peptidyl-transferase-center (PTC). Our analysis of three sequential nucleolar pre-60S intermediates reveals that the DEAD-box ATPase Dbp10/DDX54 remodels this alternate base pairing and enables the formation of the rRNA junction that anchors the mature form of the universally conserved PTC A-loop. Post-catalysis, Dbp10 captures rRNA helix H61, initiating the concerted exchange of biogenesis factors during late nucleolar 60S maturation. Our findings show that Dbp10 activity is essential for the formation of the ribosome active site and reveal how this function is integrated with subsequent assembly steps to drive the biogenesis of the large ribosomal subunit.
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5
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Bohnsack KE, Yi S, Venus S, Jankowsky E, Bohnsack MT. Cellular functions of eukaryotic RNA helicases and their links to human diseases. Nat Rev Mol Cell Biol 2023; 24:749-769. [PMID: 37474727 DOI: 10.1038/s41580-023-00628-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/22/2023]
Abstract
RNA helicases are highly conserved proteins that use nucleoside triphosphates to bind or remodel RNA, RNA-protein complexes or both. RNA helicases are classified into the DEAD-box, DEAH/RHA, Ski2-like, Upf1-like and RIG-I families, and are the largest class of enzymes active in eukaryotic RNA metabolism - virtually all aspects of gene expression and its regulation involve RNA helicases. Mutation and dysregulation of these enzymes have been linked to a multitude of diseases, including cancer and neurological disorders. In this Review, we discuss the regulation and functional mechanisms of RNA helicases and their roles in eukaryotic RNA metabolism, including in transcription regulation, pre-mRNA splicing, ribosome assembly, translation and RNA decay. We highlight intriguing models that link helicase structure, mechanisms of function (such as local strand unwinding, translocation, winching, RNA clamping and displacing RNA-binding proteins) and biological roles, including emerging connections between RNA helicases and cellular condensates formed through liquid-liquid phase separation. We also discuss associations of RNA helicases with human diseases and recent efforts towards the design of small-molecule inhibitors of these pivotal regulators of eukaryotic gene expression.
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Affiliation(s)
- Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
| | - Soon Yi
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah Venus
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Moderna, Cambridge, MA, USA.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
- Göttingen Centre for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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6
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Yeter-Alat H, Belgareh-Touzé N, Huvelle E, Banroques J, Tanner NK. The DEAD-Box RNA Helicase Ded1 Is Associated with Translating Ribosomes. Genes (Basel) 2023; 14:1566. [PMID: 37628617 PMCID: PMC10454743 DOI: 10.3390/genes14081566] [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: 06/27/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
DEAD-box RNA helicases are ATP-dependent RNA binding proteins and RNA-dependent ATPases that possess weak, nonprocessive unwinding activity in vitro, but they can form long-lived complexes on RNAs when the ATPase activity is inhibited. Ded1 is a yeast DEAD-box protein, the functional ortholog of mammalian DDX3, that is considered important for the scanning efficiency of the 48S pre-initiation complex ribosomes to the AUG start codon. We used a modified PAR-CLIP technique, which we call quicktime PAR-CLIP (qtPAR-CLIP), to crosslink Ded1 to 4-thiouridine-incorporated RNAs in vivo using UV light centered at 365 nm. The irradiation conditions are largely benign to the yeast cells and to Ded1, and we are able to obtain a high efficiency of crosslinking under physiological conditions. We find that Ded1 forms crosslinks on the open reading frames of many different mRNAs, but it forms the most extensive interactions on relatively few mRNAs, and particularly on mRNAs encoding certain ribosomal proteins and translation factors. Under glucose-depletion conditions, the crosslinking pattern shifts to mRNAs encoding metabolic and stress-related proteins, which reflects the altered translation. These data are consistent with Ded1 functioning in the regulation of translation elongation, perhaps by pausing or stabilizing the ribosomes through its ATP-dependent binding.
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Affiliation(s)
- Hilal Yeter-Alat
- Expression Génétique Microbienne, Université de Paris Cité & CNRS, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (E.H.); (J.B.)
- Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, CNRS UMR8261, EGM, 75005 Paris, France
| | - Naïma Belgareh-Touzé
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, UMR8226 CNRS, Institut de Biologie Physico-Chimique, Sorbonne Université, 13 Rue Pierre et Marie Curie, 75005 Paris, France;
| | - Emmeline Huvelle
- Expression Génétique Microbienne, Université de Paris Cité & CNRS, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (E.H.); (J.B.)
- Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, CNRS UMR8261, EGM, 75005 Paris, France
| | - Josette Banroques
- Expression Génétique Microbienne, Université de Paris Cité & CNRS, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (E.H.); (J.B.)
- Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, CNRS UMR8261, EGM, 75005 Paris, France
| | - N. Kyle Tanner
- Expression Génétique Microbienne, Université de Paris Cité & CNRS, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France; (H.Y.-A.); (E.H.); (J.B.)
- Institut de Biologie Physico-Chimique, Paris Sciences et Lettres University, CNRS UMR8261, EGM, 75005 Paris, France
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7
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Analysis and prediction of protein stability based on interaction network, gene ontology, and KEGG pathway enrichment scores. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140889. [PMID: 36610583 DOI: 10.1016/j.bbapap.2023.140889] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/18/2022] [Accepted: 01/02/2023] [Indexed: 01/06/2023]
Abstract
Metabolic stability of proteins plays a vital role in various dedicated cellular processes. Traditional methods of measuring the metabolic stability are time-consuming and expensive. Therefore, we developed a more efficient computational approach to understand the protein dynamic action mechanisms in biological process networks. In this study, we collected 341 short-lived proteins and 824 non-short-lived proteins from U2OS; 342 short-lived proteins and 821 non-short-lived proteins from HEK293T; 424 short-lived proteins and 1153 non-short-lived proteins from HCT116; and 384 short-lived proteins and 992 non-short-lived proteins from RPE1. The proteins were encoded by GO and KEGG enrichment scores based on the genes and their neighbors in STRING, resulting in 20,681 GO term features and 297 KEGG pathway features. We also incorporated the protein interaction information from STRING into the features and obtained 19,247 node features. Boruta and mRMR methods were used for feature filtering, and IFS method was used to obtain the best feature subsets and create the models with the highest performance. The present study identified 42 features that did not appear in previous studies and classified them into eight groups according to their functional annotation. By reviewing the literature, we found that the following three functional groups were critical in determining the stability of proteins: synaptic transmission, post-translational modifications, and cell fate determination. These findings may serve as a valuable reference for developing drugs that target protein stability.
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8
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Khreiss A, Capeyrou R, Lebaron S, Albert B, Bohnsack K, Bohnsack M, Henry Y, Henras A, Humbert O. The DEAD-box protein Dbp6 is an ATPase and RNA annealase interacting with the peptidyl transferase center (PTC) of the ribosome. Nucleic Acids Res 2023; 51:744-764. [PMID: 36610750 PMCID: PMC9881158 DOI: 10.1093/nar/gkac1196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/21/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
Ribosomes are ribozymes, hence correct folding of the rRNAs during ribosome biogenesis is crucial to ensure catalytic activity. RNA helicases, which can modulate RNA-RNA and RNA/protein interactions, are proposed to participate in rRNA tridimensional folding. Here, we analyze the biochemical properties of Dbp6, a DEAD-box RNA helicase required for the conversion of the initial 90S pre-ribosomal particle into the first pre-60S particle. We demonstrate that in vitro, Dbp6 shows ATPase as well as annealing and clamping activities negatively regulated by ATP. Mutations in Dbp6 core motifs involved in ATP binding and ATP hydrolysis are lethal and impair Dbp6 ATPase activity but increase its RNA binding and RNA annealing activities. These data suggest that correct regulation of these activities is important for Dbp6 function in vivo. Using in vivo cross-linking (CRAC) experiments, we show that Dbp6 interacts with 25S rRNA sequences located in the 5' domain I and in the peptidyl transferase center (PTC), and also crosslinks to snoRNAs hybridizing to the immature PTC. We propose that the ATPase and RNA clamping/annealing activities of Dbp6 modulate interactions of snoRNAs with the immature PTC and/or contribute directly to the folding of this region.
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Affiliation(s)
- Ali Khreiss
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Régine Capeyrou
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Simon Lebaron
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Benjamin Albert
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany,Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, 37077 Göttingen, Germany
| | - Yves Henry
- Correspondence may also be addressed to Yves Henry. Tel: +33 5 61 33 59 53; Fax: +33 5 61 33 58 86;
| | - Anthony K Henras
- Correspondence may also be addressed to Anthony Henras. Tel: +33 5 61 33 59 55; Fax: +33 5 61 33 58 86;
| | - Odile Humbert
- To whom correspondence should be addressed. Tel: +33 5 61 33 59 52; Fax: +33 5 61 33 58 86;
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9
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Cruz VE, Sekulski K, Peddada N, Sailer C, Balasubramanian S, Weirich CS, Stengel F, Erzberger JP. Sequence-specific remodeling of a topologically complex RNP substrate by Spb4. Nat Struct Mol Biol 2022; 29:1228-1238. [PMID: 36482249 PMCID: PMC10680166 DOI: 10.1038/s41594-022-00874-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 10/14/2022] [Indexed: 12/13/2022]
Abstract
DEAD-box ATPases are ubiquitous enzymes essential in all aspects of RNA biology. However, the limited in vitro catalytic activities described for these enzymes are at odds with their complex cellular roles, most notably in driving large-scale RNA remodeling steps during the assembly of ribonucleoproteins (RNPs). We describe cryo-EM structures of 60S ribosomal biogenesis intermediates that reveal how context-specific RNA unwinding by the DEAD-box ATPase Spb4 results in extensive, sequence-specific remodeling of rRNA secondary structure. Multiple cis and trans interactions stabilize Spb4 in a post-catalytic, high-energy intermediate that drives the organization of the three-way junction at the base of rRNA domain IV. This mechanism explains how limited strand separation by DEAD-box ATPases is leveraged to provide non-equilibrium directionality and ensure efficient and accurate RNP assembly.
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Affiliation(s)
- Victor Emmanuel Cruz
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Kamil Sekulski
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Nagesh Peddada
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Carolin Sailer
- Department of Biology, University of Konstanz, Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany
- Department of Biomedical Sciences, University of Copenhagen, København, Denmark
| | - Sahana Balasubramanian
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
- Cell Biology & Molecular Physiology Department, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christine S Weirich
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Florian Stengel
- Department of Biology, University of Konstanz, Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany
| | - Jan P Erzberger
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA.
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10
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Brai A, Trivisani CI, Poggialini F, Pasqualini C, Vagaggini C, Dreassi E. DEAD-Box Helicase DDX3X as a Host Target against Emerging Viruses: New Insights for Medicinal Chemical Approaches. J Med Chem 2022; 65:10195-10216. [PMID: 35899912 DOI: 10.1021/acs.jmedchem.2c00755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In recent years, globalization, global warming, and population aging have contributed to the spread of emerging viruses, such as coronaviruses (COVs), West Nile (WNV), Dengue (DENV), and Zika (ZIKV). The number of reported infections is increasing, and considering the high viral mutation rate, it is conceivable that it will increase significantly in the coming years. The risk caused by viruses is now more evident due to the COVID-19 pandemic, which highlighted the need to find new broad-spectrum antiviral agents able to tackle the present pandemic and future epidemics. DDX3X helicase is a host factor required for viral replication. Selective inhibitors have been identified and developed into broad-spectrum antivirals active against emerging pathogens, including SARS-CoV-2 and most importantly against drug-resistant strains. This perspective describes the inhibitors identified in the last years, highlighting their therapeutic potential as innovative broad-spectrum antivirals.
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Affiliation(s)
- Annalaura Brai
- Department of Biotechnology, Chemistry & Pharmacy, University of Siena, I-53100 Siena Italy
| | | | - Federica Poggialini
- Department of Biotechnology, Chemistry & Pharmacy, University of Siena, I-53100 Siena Italy
| | - Claudia Pasqualini
- Department of Biotechnology, Chemistry & Pharmacy, University of Siena, I-53100 Siena Italy
| | - Chiara Vagaggini
- Department of Biotechnology, Chemistry & Pharmacy, University of Siena, I-53100 Siena Italy
| | - Elena Dreassi
- Department of Biotechnology, Chemistry & Pharmacy, University of Siena, I-53100 Siena Italy
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11
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Venus S, Jankowsky E. Measuring the impact of cofactors on RNA helicase activities. Methods 2022; 204:376-385. [PMID: 35429628 PMCID: PMC9306305 DOI: 10.1016/j.ymeth.2022.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/03/2022] [Accepted: 04/12/2022] [Indexed: 12/25/2022] Open
Abstract
RNA helicases are the largest class of enzymes in eukaryotic RNA metabolism. In cells, protein cofactors regulate RNA helicase functions and impact biochemical helicase activities. Understanding how cofactors affect enzymatic activities of RNA helicases is thus critical for delineating physical roles and regulation of RNA helicases in cells. Here, we discuss approaches and conceptual considerations for the design of experiments to interrogate cofactor effects on RNA helicase activities in vitro. We outline the mechanistic frame for helicase reactions, discuss optimization of experimental setup and reaction parameters for measuring cofactor effects on RNA helicase activities, and provide basic guides to data analysis and interpretation. The described approaches are also instructive for determining the impact of small molecule inhibitors of RNA helicases.
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12
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Yang C, Dominique GM, Champion MM, Huber PW. Remnants of the Balbiani body are required for formation of RNA transport granules in Xenopus oocytes. iScience 2022; 25:103878. [PMID: 35243240 PMCID: PMC8861640 DOI: 10.1016/j.isci.2022.103878] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 12/24/2021] [Accepted: 02/02/2022] [Indexed: 11/29/2022] Open
Abstract
The Balbiani body (Bb), an organelle comprised of mitochondria, ER, and RNA, is found in the oocytes of most organisms. In Xenopus, the structure is initially positioned immediately adjacent to the nucleus, extends toward the vegetal pole, and eventually disperses, leaving behind a region highly enriched in mitochondria. This area is later transversed by RNP complexes that are being localized to the vegetal cortex. Inhibition of mitochondrial ATP synthesis prevents perinuclear formation of the transport complexes that can be reversed by a nonhydrolyzable ATP analog, indicating the nucleotide is acting as a hydrotrope. The protein composition, sensitivity to hexanediol, and coalescence in the absence of transport provide evidence that the transport RNP complexes are biocondensates. The breakdown of the Bb engenders regions of clustered mitochondria that are used not to meet extraordinary energy demands, but rather to promote a liquid-liquid phase separation.
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Affiliation(s)
- Chao Yang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Gena M. Dominique
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Matthew M. Champion
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Paul W. Huber
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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13
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Weis K, Hondele M. The Role of DEAD-Box ATPases in Gene Expression and the Regulation of RNA-Protein Condensates. Annu Rev Biochem 2022; 91:197-219. [PMID: 35303788 DOI: 10.1146/annurev-biochem-032620-105429] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DEAD-box ATPases constitute a very large protein family present in all cells, often in great abundance. From bacteria to humans, they play critical roles in many aspects of RNA metabolism, and due to their widespread importance in RNA biology, they have been characterized in great detail at both the structural and biochemical levels. DEAD-box proteins function as RNA-dependent ATPases that can unwind short duplexes of RNA, remodel ribonucleoprotein (RNP) complexes, or act as clamps to promote RNP assembly. Yet, it often remains enigmatic how individual DEAD-box proteins mechanistically contribute to specific RNA-processing steps. Here, we review the role of DEAD-box ATPases in the regulation of gene expression and propose that one common function of these enzymes is in the regulation of liquid-liquid phase separation of RNP condensates. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Karsten Weis
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland;
| | - Maria Hondele
- Biozentrum, University of Basel, Basel, Switzerland;
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14
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Loh D, Reiter RJ. Melatonin: Regulation of Biomolecular Condensates in Neurodegenerative Disorders. Antioxidants (Basel) 2021; 10:1483. [PMID: 34573116 PMCID: PMC8465482 DOI: 10.3390/antiox10091483] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Biomolecular condensates are membraneless organelles (MLOs) that form dynamic, chemically distinct subcellular compartments organizing macromolecules such as proteins, RNA, and DNA in unicellular prokaryotic bacteria and complex eukaryotic cells. Separated from surrounding environments, MLOs in the nucleoplasm, cytoplasm, and mitochondria assemble by liquid-liquid phase separation (LLPS) into transient, non-static, liquid-like droplets that regulate essential molecular functions. LLPS is primarily controlled by post-translational modifications (PTMs) that fine-tune the balance between attractive and repulsive charge states and/or binding motifs of proteins. Aberrant phase separation due to dysregulated membrane lipid rafts and/or PTMs, as well as the absence of adequate hydrotropic small molecules such as ATP, or the presence of specific RNA proteins can cause pathological protein aggregation in neurodegenerative disorders. Melatonin may exert a dominant influence over phase separation in biomolecular condensates by optimizing membrane and MLO interdependent reactions through stabilizing lipid raft domains, reducing line tension, and maintaining negative membrane curvature and fluidity. As a potent antioxidant, melatonin protects cardiolipin and other membrane lipids from peroxidation cascades, supporting protein trafficking, signaling, ion channel activities, and ATPase functionality during condensate coacervation or dissolution. Melatonin may even control condensate LLPS through PTM and balance mRNA- and RNA-binding protein composition by regulating N6-methyladenosine (m6A) modifications. There is currently a lack of pharmaceuticals targeting neurodegenerative disorders via the regulation of phase separation. The potential of melatonin in the modulation of biomolecular condensate in the attenuation of aberrant condensate aggregation in neurodegenerative disorders is discussed in this review.
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Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX 78229, USA
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15
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Tilly BC, Chalkley GE, van der Knaap JA, Moshkin YM, Kan TW, Dekkers DH, Demmers JA, Verrijzer CP. In vivo analysis reveals that ATP-hydrolysis couples remodeling to SWI/SNF release from chromatin. eLife 2021; 10:69424. [PMID: 34313222 PMCID: PMC8352592 DOI: 10.7554/elife.69424] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/26/2021] [Indexed: 12/23/2022] Open
Abstract
ATP-dependent chromatin remodelers control the accessibility of genomic DNA through nucleosome mobilization. However, the dynamics of genome exploration by remodelers, and the role of ATP hydrolysis in this process remain unclear. We used live-cell imaging of Drosophila polytene nuclei to monitor Brahma (BRM) remodeler interactions with its chromosomal targets. In parallel, we measured local chromatin condensation and its effect on BRM association. Surprisingly, only a small portion of BRM is bound to chromatin at any given time. BRM binds decondensed chromatin but is excluded from condensed chromatin, limiting its genomic search space. BRM-chromatin interactions are highly dynamic, whereas histone-exchange is limited and much slower. Intriguingly, loss of ATP hydrolysis enhanced chromatin retention and clustering of BRM, which was associated with reduced histone turnover. Thus, ATP hydrolysis couples nucleosome remodeling to remodeler release, driving a continuous transient probing of the genome.
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Affiliation(s)
- Ben C Tilly
- Department of Biochemistry, Rotterdam, Netherlands
| | | | | | | | | | - Dick Hw Dekkers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Jeroen Aa Demmers
- Department of Biochemistry, Rotterdam, Netherlands.,Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands
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16
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Whitford DS, Whitman BT, Owttrim GW. Genera specific distribution of DEAD-box RNA helicases in cyanobacteria. Microb Genom 2021; 7. [PMID: 33539277 PMCID: PMC8190605 DOI: 10.1099/mgen.0.000517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Although RNA helicases are essentially ubiquitous and perform roles in all stages of RNA metabolism, phylogenetic analysis of the DEAD (Asp-Glu-Ala-Asp)-box RNA helicase family in a single phylum has not been performed. Here, we performed a phylogenetic analysis on DEAD-box helicases from all currently available cyanobacterial genomes, comprising a total of 362 helicase protein sequences from 280 strains. DEAD-box helicases belonging to three distinct clades were observed. Two clades, the CsdA (cold shock DEAD-box A)-like and RhlE (RNA helicase E)-like helicases, cluster with the homologous proteins from Escherichia coli. The third clade, the CrhR (cyanobacterial RNA helicase Redox)-like helicases, is unique to cyanobacteria and characterized by a conserved sequence motif in the C-terminal extension. Restricted distribution is observed across cyanobacterial diversity with respect to both helicase type and strain. CrhR-like and CsdA-like helicases essentially never occur together, while RhlE always occurs with either a CrhR-like or CsdA-like helicase. CrhR-like and RhlE-like proteins occurred in filamentous cyanobacteria of the orders Nostocales, Oscillatoriales and Synechococcales. Similarly, CsdA- and RhlE-like proteins are restricted to unicellular cyanobacteria of the genera Cyanobium and Synechococcus. In addition, the unexpected occurrence of RhlE in two Synechococcus strains suggests recent acquisition and evolutionary divergence. This study, therefore, raises physiological and evolutionary questions as to why DEAD-box RNA helicases encoded in cyanobacterial lineages display restricted distributions, suggesting niches that require either CrhR or CsdA RNA helicase activity but not both. Extensive conservation of gene synteny surrounding the previously described rimO–crhR operon is also observed, indicating a role in the maintenance of photosynthesis. The analysis provides insights into the evolution, origin and dissemination of sequences within a single gene family to yield divergent functional roles.
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Affiliation(s)
- Denise S Whitford
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Brendan T Whitman
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
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17
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Chang-Gu B, Bradburn D, Yangyuoru PM, Russell R. The DHX36-specific-motif (DSM) enhances specificity by accelerating recruitment of DNA G-quadruplex structures. Biol Chem 2020; 402:593-604. [PMID: 33857359 DOI: 10.1515/hsz-2020-0302] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 12/07/2020] [Indexed: 01/15/2023]
Abstract
DHX36 is a eukaryotic DEAH/RHA family helicase that disrupts G-quadruplex structures (G4s) with high specificity, contributing to regulatory roles of G4s. Here we used a DHX36 truncation to examine the roles of the 13-amino acid DHX36-specific motif (DSM) in DNA G4 recognition and disruption. We found that the DSM promotes G4 recognition and specificity by increasing the G4 binding rate of DHX36 without affecting the dissociation rate. Further, for most of the G4s measured, the DSM has little or no effect on the G4 disruption step by DHX36, implying that contacts with the G4 are maintained through the transition state for G4 disruption. This result suggests that partial disruption of the G4 from the 3' end is sufficient to reach the overall transition state for G4 disruption, while the DSM remains unperturbed at the 5' end. Interestingly, the DSM does not contribute to G4 binding kinetics or thermodynamics at low temperature, indicating a highly modular function. Together, our results animate recent DHX36 crystal structures, suggesting a model in which the DSM recruits G4s in a modular and flexible manner by contacting the 5' face early in binding, prior to rate-limiting capture and disruption of the G4 by the helicase core.
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Affiliation(s)
- Bruce Chang-Gu
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX78712, USA
| | - Devin Bradburn
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX78712, USA.,Department of Biology, Stanford University, Stanford, CA94305, USA
| | - Philip M Yangyuoru
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX78712, USA.,Department of Chemistry, Northern Michigan University, Marquette, MI49855, USA
| | - Rick Russell
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX78712, USA
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18
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Key Points to Consider When Studying RNA Remodeling by Proteins. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2020; 2209:1-16. [PMID: 33201459 DOI: 10.1007/978-1-0716-0935-4_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Cellular RNAs depend on proteins for efficient folding to specific functional structures and for transitions between functional structures. This dependence arises from intrinsic properties of RNA structure. Specifically, RNAs possess stable local structure, largely in the form of helices, and there are abundant opportunities for RNAs to form alternative helices and tertiary contacts and therefore to populate alternative structures. Proteins with RNA chaperone activity, either ATP-dependent or ATP-independent, can promote structural transitions by interacting with single-stranded RNA (ssRNA) to compete away partner interactions and then release ssRNA so that it can form new interactions. In this chapter we review the basic properties of RNA and the proteins that function as chaperones and remodelers. We then use these properties as a foundation to explore key points for the design and interpretation of experiments that probe RNA rearrangements and their acceleration by proteins.
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19
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Wu CY, Nagy PD. Role reversal of functional identity in host factors: Dissecting features affecting pro-viral versus antiviral functions of cellular DEAD-box helicases in tombusvirus replication. PLoS Pathog 2020; 16:e1008990. [PMID: 33035275 PMCID: PMC7577489 DOI: 10.1371/journal.ppat.1008990] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 10/21/2020] [Accepted: 09/14/2020] [Indexed: 12/22/2022] Open
Abstract
Positive-stranded (+)RNA viruses greatly exploit host cells to support viral replication. However, unlike many other pathogens, (+)RNA viruses code for only a limited number of genes, making them highly dependent on numerous co-opted host factors for supporting viral replication and other viral processes during their infections. This excessive dependence on subverted host factors, however, renders (+)RNA viruses vulnerable to host restriction factors that could block virus replication. Interestingly, cellular ATP-dependent DEAD-box RNA helicases could promote or inhibit the replication of Tomato bushy stunt virus (TBSV) replication. However, it is currently unknown what features make a particular DEAD-box helicase either pro-viral or antiviral. In this work, we succeeded in reversing the viral function of the antiviral DDX17-like RH30 DEAD-box helicase by converting it to a pro-viral helicase. We also turned the pro-viral DDX3-like RH20 helicase into an antiviral helicase through deletion of a unique N-terminal domain. We demonstrate that in the absence of the N-terminal domain, the core helicase domain becomes unhinged, showing altered specificity in unwinding viral RNA duplexes containing cis-acting replication elements. The discovery of the sequence plasticity of DEAD-box helicases that can alter recognition of different cis-acting RNA elements in the viral genome illustrates the evolutionary potential of RNA helicases in the arms race between viruses and their hosts, including key roles of RNA helicases in plant innate immunity. Overall, these findings open up the possibility to turn the pro-viral host factors into antiviral factors, thus increasing the potential antiviral arsenal of the host for the benefit of agriculture and health science. The largest group of eukaryotic viruses, the positive-strand RNA viruses, depends greatly on co-opting host components to support their replication. This dependence on host factors by these viruses also makes them vulnerable to antiviral factors. This is well-illustrated in case of tombusviruses, a small RNA viruses of plants. Tombusviruses co-opt many host factors to support various steps in their replication. Among these host factors are cellular DEAD-box helicases, which help remodeling viral RNA structures during the RNA replication process. However, similar cellular helicases remodel the viral RNAs incorrectly, making them antiviral or restriction factors. To gain insights into what makes a particular DEAD-box helicase pro-viral or antiviral, in this work, we converted the antiviral plant RH30 helicase into a pro-viral helicase through modifying the N-terminal sequences. We also succeeded to turn the originally pro-viral plant RH20 helicase into an antiviral helicase using a similar strategy. By characterizing the newly acquired functions of these helicases, we obtained valuable insights into what features make these helicases either pro-viral or antiviral. These discoveries have implications to better understand the arms race between viruses and hosts. In addition, it opens up the opportunity to generate new antiviral tools by converting pro-viral host factors into antiviral factors, thus enhancing our molecular tools against the ever-evolving RNA viruses.
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Affiliation(s)
- Cheng-Yu Wu
- Department of Plant Pathology, University of Kentucky, Lexington, Lexington, United States of America
| | - Peter D. Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Lexington, United States of America
- * E-mail:
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20
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In-silico analysis of eukaryotic translation initiation factors (eIFs) in response to environmental stresses in rice (Oryza sativa). Biologia (Bratisl) 2020. [DOI: 10.2478/s11756-020-00467-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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21
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DEAD-box RNA Helicase DDX3: Functional Properties and Development of DDX3 Inhibitors as Antiviral and Anticancer Drugs. Molecules 2020; 25:molecules25041015. [PMID: 32102413 PMCID: PMC7070539 DOI: 10.3390/molecules25041015] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/05/2020] [Accepted: 02/21/2020] [Indexed: 12/11/2022] Open
Abstract
This short review is focused on enzymatic properties of human ATP-dependent RNA helicase DDX3 and the development of antiviral and anticancer drugs targeting cellular helicases. DDX3 belongs to the DEAD-box proteins, a large family of RNA helicases that participate in all aspects of cellular processes, such as cell cycle progression, apoptosis, innate immune response, viral replication, and tumorigenesis. DDX3 has a variety of functions in the life cycle of different viruses. DDX3 helicase is required to facilitate both the Rev-mediated export of unspliced/partially spliced human immunodeficiency virus (HIV) RNA from nucleus and Tat-dependent translation of viral genes. DDX3 silencing blocks the replication of HIV, HCV, and some other viruses. On the other hand, DDX displays antiviral effect against Dengue virus and hepatitis B virus through the stimulation of interferon beta production. The role of DDX3 in different types of cancer is rather controversial. DDX3 acts as an oncogene in one type of cancer, but demonstrates tumor suppressor properties in other types. The human DDX3 helicase is now considered as a new attractive target for the development of novel pharmaceutical drugs. The most interesting inhibitors of DDX3 helicase and the mechanisms of their actions as antiviral or anticancer drugs are discussed in this short review.
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22
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Licatalosi DD, Ye X, Jankowsky E. Approaches for measuring the dynamics of RNA-protein interactions. WILEY INTERDISCIPLINARY REVIEWS. RNA 2020; 11:e1565. [PMID: 31429211 PMCID: PMC7006490 DOI: 10.1002/wrna.1565] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/20/2019] [Accepted: 07/25/2019] [Indexed: 12/17/2022]
Abstract
RNA-protein interactions are pivotal for the regulation of gene expression from bacteria to human. RNA-protein interactions are dynamic; they change over biologically relevant timescales. Understanding the regulation of gene expression at the RNA level therefore requires knowledge of the dynamics of RNA-protein interactions. Here, we discuss the main experimental approaches to measure dynamic aspects of RNA-protein interactions. We cover techniques that assess dynamics of cellular RNA-protein interactions that accompany biological processes over timescales of hours or longer and techniques measuring the kinetic dynamics of RNA-protein interactions in vitro. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Evolution and Genomics > Ribonomics.
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Affiliation(s)
- Donny D Licatalosi
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Xuan Ye
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, Ohio
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23
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Ren R, Ghassabi Kondalaji S, Bowman GD. The Chd1 chromatin remodeler forms long-lived complexes with nucleosomes in the presence of ADP·BeF 3 - and transition state analogs. J Biol Chem 2019; 294:18181-18191. [PMID: 31636125 DOI: 10.1074/jbc.ra119.009782] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/17/2019] [Indexed: 01/03/2023] Open
Abstract
Chromatin remodelers use helicase-like ATPase domains to reorganize histone-DNA contacts within the nucleosome. Like other remodelers, the chromodomain helicase DNA-binding protein 1 (Chd1) remodeler repositions nucleosomes by altering DNA topology at its internal binding site on the nucleosome, coupling different degrees of DNA twist and DNA movement to distinct nucleotide-bound states of the ATPase motor. In this work, we used a competition assay to study how variations in the bound nucleotide, Chd1, and the nucleosome substrate affect stability of Chd1-nucleosome complexes. We found that Chd1-nucleosome complexes formed in nucleotide-free or ADP conditions were relatively unstable and dissociated within 30 s, whereas those with the nonhydrolyzable ATP analog AMP-PNP had a mean lifetime of 4.8 ± 0.7 min. Chd1-nucleosome complexes were remarkably stable with ADP·BeF3 - and the transition state analogs ADP·AlFX and ADP·MgFX, being resistant to competitor nucleosome over a 24-h period. For the tight ADP·BeF3 --stabilized complex, Mg2+ was a critical component that did not freely exchange, and formation of these long-lived complexes had a slow, concentration-dependent step. The ADP·BeF3 --stabilized complex did not require the Chd1 DNA-binding domain nor the histone H4 tail and appeared relatively insensitive to sequence differences on either side of the Widom 601 sequence. Interestingly, the complex remained stable in ADP·BeF3 - even when nucleosomes contained single-stranded gaps that disrupted most DNA contacts with the guide strand. This finding suggests that binding via the tracking strand alone is sufficient for stabilizing the complex in a hydrolysis-competent state.
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Affiliation(s)
- Ren Ren
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218
| | | | - Gregory D Bowman
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218.
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24
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de Bisschop G, Ameur M, Ulryck N, Benattia F, Ponchon L, Sargueil B, Chamond N. HIV-1 gRNA, a biological substrate, uncovers the potency of DDX3X biochemical activity. Biochimie 2019; 164:83-94. [PMID: 30910425 DOI: 10.1016/j.biochi.2019.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/12/2019] [Indexed: 11/30/2022]
Abstract
DEAD-box helicases play central roles in the metabolism of many RNAs and ribonucleoproteins by assisting their synthesis, folding, function and even their degradation or disassembly. They have been implicated in various phenomena, and it is often difficult to rationalize their molecular roles from in vivo studies. Once purified in vitro, most of them only exhibit a marginal activity and poor specificity. The current model is that they gain specificity and activity through interaction of their intrinsically disordered domains with specific RNA or proteins. DDX3 is a DEAD-box cellular helicase that has been involved in several steps of the HIV viral cycle, including transcription, RNA export to the cytoplasm and translation. In this study, we investigated DDX3 biochemical properties in the context of a biological substrate. DDX3 was overexpressed, purified and its enzymatic activities as well as its RNA binding properties were characterized using both model substrates and a biological substrate, HIV-1 gRNA. Biochemical characterization of DDX3 in the context of a biological substrate identifies HIV-1 gRNA as a rare example of specific substrate and unravels the extent of DDX3 ATPase activity. Analysis of DDX3 binding capacity indicates an unexpected dissociation between its binding capacity and its biochemical activity. We further demonstrate that interaction of DDX3 with HIV-1 gRNA relies both on specific RNA determinants and on the disordered N- and C-terminal regions of the protein. These findings shed a new light regarding the potentiality of DDX3 biochemical activity supporting its multiple cellular functions.
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Affiliation(s)
| | - Mélissa Ameur
- CiTCOM, Université Paris Descartes, CNRS UMR 8038, Paris, France
| | - Nathalie Ulryck
- CiTCOM, Université Paris Descartes, CNRS UMR 8038, Paris, France
| | - Fatima Benattia
- CiTCOM, Université Paris Descartes, CNRS UMR 8038, Paris, France
| | - Luc Ponchon
- CiTCOM, Université Paris Descartes, CNRS UMR 8038, Paris, France
| | - Bruno Sargueil
- CiTCOM, Université Paris Descartes, CNRS UMR 8038, Paris, France.
| | - Nathalie Chamond
- CiTCOM, Université Paris Descartes, CNRS UMR 8038, Paris, France.
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25
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Wong EV, Gray S, Cao W, Montpetit R, Montpetit B, De La Cruz EM. Nup159 Weakens Gle1 Binding to Dbp5 But Does Not Accelerate ADP Release. J Mol Biol 2018; 430:2080-2095. [PMID: 29782832 DOI: 10.1016/j.jmb.2018.05.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/03/2018] [Accepted: 05/15/2018] [Indexed: 12/17/2022]
Abstract
Dbp5, DDX19 in humans, is an essential DEAD-box protein involved in mRNA export, which has also been linked to other cellular processes, including rRNA export and translation. Dbp5 ATPase activity is regulated by several factors, including RNA, the nucleoporin proteins Nup159 and Gle1, and the endogenous small-molecule inositol hexakisphosphate (InsP6). To better understand how these factors modulate Dbp5 activity and how this modulation relates to in vivo RNA metabolism, a detailed characterization of the Dbp5 mechanochemical cycle in the presence of those regulators individually or together is necessary. In this study, we test the hypothesis that Nup159 controls the ADP-bound state of Dbp5. In addition, the contributions of Mg2+ to the kinetics and thermodynamics of ADP binding to Dbp5 were assessed. Using a solution based in vitro approach, Mg2+ was found to slow ADP and ATP release from Dbp5 and increased the overall ADP and ATP affinities, as observed with other NTPases. Furthermore, Nup159 did not accelerate ADP release, while Gle1 actually slowed ADP release independent of Mg2+. These findings are not consistent with Nup159 acting as a nucleotide exchange factor to promote ADP release and Dbp5 ATPase cycling. Instead, in the presence of Nup159, the interaction between Gle1 and ADP-bound Dbp5 was found to be reduced by ~18-fold, suggesting that Nup159 alters the Dbp5-Gle1 interaction to aid Gle1 release from Dbp5.
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Affiliation(s)
- Emily V Wong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Shawn Gray
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Wenxiang Cao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Rachel Montpetit
- Department of Viticulture and Enology, University of California, Davis, Davis, CA 95616, USA; Department of Food Science and Technology, University of California, Davis, Davis, CA 95616, USA
| | - Ben Montpetit
- Department of Viticulture and Enology, University of California, Davis, Davis, CA 95616, USA; Department of Food Science and Technology, University of California, Davis, Davis, CA 95616, USA.
| | - Enrique M De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
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26
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Distinct RNA-unwinding mechanisms of DEAD-box and DEAH-box RNA helicase proteins in remodeling structured RNAs and RNPs. Biochem Soc Trans 2017; 45:1313-1321. [PMID: 29150525 DOI: 10.1042/bst20170095] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/16/2017] [Accepted: 10/23/2017] [Indexed: 01/03/2023]
Abstract
Structured RNAs and RNA-protein complexes (RNPs) fold through complex pathways that are replete with misfolded traps, and many RNAs and RNPs undergo extensive conformational changes during their functional cycles. These folding steps and conformational transitions are frequently promoted by RNA chaperone proteins, notably by superfamily 2 (SF2) RNA helicase proteins. The two largest families of SF2 helicases, DEAD-box and DEAH-box proteins, share evolutionarily conserved helicase cores, but unwind RNA helices through distinct mechanisms. Recent studies have advanced our understanding of how their distinct mechanisms enable DEAD-box proteins to disrupt RNA base pairs on the surfaces of structured RNAs and RNPs, while some DEAH-box proteins are adept at disrupting base pairs in the interior of RNPs. Proteins from these families use these mechanisms to chaperone folding and promote rearrangements of structured RNAs and RNPs, including the spliceosome, and may use related mechanisms to maintain cellular messenger RNAs in unfolded or partially unfolded conformations.
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27
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Götze M, Dufourt J, Ihling C, Rammelt C, Pierson S, Sambrani N, Temme C, Sinz A, Simonelig M, Wahle E. Translational repression of the Drosophila nanos mRNA involves the RNA helicase Belle and RNA coating by Me31B and Trailer hitch. RNA (NEW YORK, N.Y.) 2017; 23:1552-1568. [PMID: 28701521 PMCID: PMC5602113 DOI: 10.1261/rna.062208.117] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/10/2017] [Indexed: 05/10/2023]
Abstract
Translational repression of maternal mRNAs is an essential regulatory mechanism during early embryonic development. Repression of the Drosophila nanos mRNA, required for the formation of the anterior-posterior body axis, depends on the protein Smaug binding to two Smaug recognition elements (SREs) in the nanos 3' UTR. In a comprehensive mass spectrometric analysis of the SRE-dependent repressor complex, we identified Smaug, Cup, Me31B, Trailer hitch, eIF4E, and PABPC, in agreement with earlier data. As a novel component, the RNA-dependent ATPase Belle (DDX3) was found, and its involvement in deadenylation and repression of nanos was confirmed in vivo. Smaug, Cup, and Belle bound stoichiometrically to the SREs, independently of RNA length. Binding of Me31B and Tral was also SRE-dependent, but their amounts were proportional to the length of the RNA and equimolar to each other. We suggest that "coating" of the RNA by a Me31B•Tral complex may be at the core of repression.
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Affiliation(s)
- Michael Götze
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Jérémy Dufourt
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Christian Ihling
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Christiane Rammelt
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Stephanie Pierson
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Nagraj Sambrani
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Claudia Temme
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Andrea Sinz
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Martine Simonelig
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Elmar Wahle
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
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28
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Xing Z, Wang S, Tran EJ. Characterization of the mammalian DEAD-box protein DDX5 reveals functional conservation with S. cerevisiae ortholog Dbp2 in transcriptional control and glucose metabolism. RNA (NEW YORK, N.Y.) 2017; 23:1125-1138. [PMID: 28411202 PMCID: PMC5473146 DOI: 10.1261/rna.060335.116] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 04/10/2017] [Indexed: 05/09/2023]
Abstract
DEAD-box proteins are a class of nonprocessive RNA helicases that dynamically modulate the structure of RNA and ribonucleoprotein complexes (RNPs). However, the precise roles of individual members are not well understood. Work from our laboratory revealed that the DEAD-box protein Dbp2 in Saccharomyces cerevisiae is an active RNA helicase in vitro that functions in transcription by promoting mRNP assembly, repressing cryptic transcription initiation, and regulating long noncoding RNA activity. Interestingly, Dbp2 is also linked to glucose sensing and hexose transporter gene expression. DDX5 is the mammalian ortholog of Dbp2 that has been implicated in cancer and metabolic syndrome, suggesting that the role of Dbp2 and DDX5 in glucose metabolic regulation is conserved. Herein, we present a refined biochemical and biological comparison of yeast Dbp2 and human DDX5 enzymes. We find that human DDX5 possesses a 10-fold higher unwinding activity than Dbp2, which is partially due to the presence of a mammalian/avian specific C-terminal extension. Interestingly, ectopic expression of DDX5 rescues the cold sensitivity, cryptic initiation defects, and impaired glucose import in dbp2Δ cells, suggesting functional conservation. Consistently, we show that DDX5 promotes glucose uptake and glycolysis in mouse AML12 hepatocyte cells, suggesting that mammalian DDX5 and S. cerevisiae Dbp2 share conserved roles in cellular metabolism.
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Affiliation(s)
- Zheng Xing
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47906, USA
| | - Siwen Wang
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47906, USA
| | - Elizabeth J Tran
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47906, USA
- Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47906, USA
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29
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Mechanism and Regulation of Protein Synthesis in Saccharomyces cerevisiae. Genetics 2017; 203:65-107. [PMID: 27183566 DOI: 10.1534/genetics.115.186221] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/24/2016] [Indexed: 12/18/2022] Open
Abstract
In this review, we provide an overview of protein synthesis in the yeast Saccharomyces cerevisiae The mechanism of protein synthesis is well conserved between yeast and other eukaryotes, and molecular genetic studies in budding yeast have provided critical insights into the fundamental process of translation as well as its regulation. The review focuses on the initiation and elongation phases of protein synthesis with descriptions of the roles of translation initiation and elongation factors that assist the ribosome in binding the messenger RNA (mRNA), selecting the start codon, and synthesizing the polypeptide. We also examine mechanisms of translational control highlighting the mRNA cap-binding proteins and the regulation of GCN4 and CPA1 mRNAs.
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30
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The multiple functions of RNA helicases as drivers and regulators of gene expression. Nat Rev Mol Cell Biol 2016; 17:426-38. [PMID: 27251421 DOI: 10.1038/nrm.2016.50] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RNA helicases comprise the largest family of enzymes involved in the metabolism of mRNAs, the processing and fate of which rely on their packaging into messenger ribonucleoprotein particles (mRNPs). In this Review, we describe how the capacity of some RNA helicases to either remodel or lock the composition of mRNP complexes underlies their pleiotropic functions at different steps of the gene expression process. We illustrate the roles of RNA helicases in coordinating gene expression steps and programmes, and propose that RNA helicases function as molecular drivers and guides of the progression of their mRNA substrates from one RNA-processing factory to another, to a productive mRNA pool that leads to protein synthesis or to unproductive mRNA pools that are stored or degraded.
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31
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Recruitment, Duplex Unwinding and Protein-Mediated Inhibition of the Dead-Box RNA Helicase Dbp2 at Actively Transcribed Chromatin. J Mol Biol 2016; 428:1091-1106. [PMID: 26876600 DOI: 10.1016/j.jmb.2016.02.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/26/2016] [Accepted: 02/02/2016] [Indexed: 02/07/2023]
Abstract
RNA helicases play fundamental roles in modulating RNA structures and facilitating RNA-protein (RNP) complex assembly in vivo. Previously, our laboratory demonstrated that the DEAD-box RNA helicase Dbp2 in Saccharomyces cerevisiae is required to promote efficient assembly of the co-transcriptionally associated mRNA-binding proteins Yra1, Nab2, and Mex67 onto poly(A)(+)RNA. We also found that Yra1 associates directly with Dbp2 and functions as an inhibitor of Dbp2-dependent duplex unwinding, suggestive of a cycle of unwinding and inhibition by Dbp2. To test this, we undertook a series of experiments to shed light on the order of events for Dbp2 in co-transcriptional mRNP assembly. We now show that Dbp2 is recruited to chromatin via RNA and forms a large, RNA-dependent complex with Yra1 and Mex67. Moreover, single-molecule fluorescence resonance energy transfer and bulk biochemical assays show that Yra1 inhibits unwinding in a concentration-dependent manner by preventing the association of Dbp2 with single-stranded RNA. This inhibition prevents over-accumulation of Dbp2 on mRNA and stabilization of a subset of RNA polymerase II transcripts. We propose a model whereby Yra1 terminates a cycle of mRNP assembly by Dbp2.
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32
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Wong EV, Cao W, Vörös J, Merchant M, Modis Y, Hackney DD, Montpetit B, De La Cruz EM. P(I) Release Limits the Intrinsic and RNA-Stimulated ATPase Cycles of DEAD-Box Protein 5 (Dbp5). J Mol Biol 2015; 428:492-508. [PMID: 26730886 PMCID: PMC4744555 DOI: 10.1016/j.jmb.2015.12.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/09/2015] [Accepted: 12/22/2015] [Indexed: 12/20/2022]
Abstract
mRNA export from the nucleus depends on the ATPase activity of the DEAD-box protein Dbp5/DDX19. Although Dbp5 has measurable ATPase activity alone, several regulatory factors (e.g., RNA, nucleoporin proteins, and the endogenous small molecule InsP6) modulate catalytic activity in vitro and in vivo to facilitate mRNA export. An analysis of the intrinsic and regulator-activated Dbp5 ATPase cycle is necessary to define how these factors control Dbp5 and mRNA export. Here, we report a kinetic and equilibrium analysis of the Saccharomyces cerevisiae Dbp5 ATPase cycle, including the influence of RNA on Dbp5 activity. These data show that ATP binds Dbp5 weakly in rapid equilibrium with a binding affinity (KT ~ 4 mM) comparable to the KM for steady-state cycling, while ADP binds an order of magnitude more tightly (KD ~ 0.4 mM). The overall intrinsic steady-state cycling rate constant (kcat) is limited by slow, near-irreversible ATP hydrolysis and even slower subsequent phosphate release. RNA increases kcat and rate-limiting Pi release 20-fold, although Pi release continues to limit steady-state cycling in the presence of RNA, in conjunction with RNA binding. Together, this work identifies RNA binding and Pi release as important biochemical transitions within the Dbp5 ATPase cycle and provides a framework for investigating the means by which Dbp5 and mRNA export is modulated by regulatory factors. mRNA export from the nucleus requires DEAD-box protein Dbp5/DDX19 ATPase activity. Kinetics and thermodynamics of intrinsic Dbp5 ATPase reveal RNA's effect on Dbp5. Intrinsic Dbp5 ATPase is limited by slow ATP hydrolysis and slower Pi release. RNA activates Pi release, but it and RNA binding still limit RNA-stimulated ATPase. RNA binding and Pi release define RNA-stimulated Dbp5 ATPase for further regulation.
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Affiliation(s)
- Emily V Wong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Wenxiang Cao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Judit Vörös
- Department of Cell Biology, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Monique Merchant
- Department of Medicine, University of Cambridge, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Yorgo Modis
- Department of Medicine, University of Cambridge, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - David D Hackney
- Department of Biological Sciences and Center for Nucleic Acids Science and Technology, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, AB, T6G 2H7, Canada.
| | - Enrique M De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA.
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33
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Putnam AA, Gao Z, Liu F, Jia H, Yang Q, Jankowsky E. Division of Labor in an Oligomer of the DEAD-Box RNA Helicase Ded1p. Mol Cell 2015. [PMID: 26212457 DOI: 10.1016/j.molcel.2015.06.030] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Most aspects of RNA metabolism involve DEAD-box RNA helicases, enzymes that bind and remodel RNA and RNA-protein complexes in an ATP-dependent manner. Here we show that the DEAD-box helicase Ded1p oligomerizes in the cell and in vitro, and unwinds RNA as a trimer. Two protomers bind the single-stranded region of RNA substrates and load a third protomer to the duplex, which then separates the strands. ATP utilization differs between the strand-separating protomer and those bound to the single-stranded region. Binding of the eukaryotic initiation factor 4G to Ded1p interferes with oligomerization and thereby modulates unwinding activity and RNA affinity of the helicase. Our data reveal a strict division of labor between the Ded1p protomers in the oligomer. This mode of oligomerization fundamentally differs from other helicases. Oligomerization represents a previously unappreciated level of regulation for DEAD-box helicase activities.
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Affiliation(s)
- Andrea A Putnam
- Center for RNA Molecular Biology and Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Zhaofeng Gao
- Center for RNA Molecular Biology and Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Fei Liu
- Center for RNA Molecular Biology and Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; College of Veterinary Medicine, Nanjing Agricultural University, Number 1 Weigang, Nanjing 210095, P.R. China
| | - Huijue Jia
- Center for RNA Molecular Biology and Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; BGI Shenzen, Beishan Industrial Zone, Yantian District, Shenzhen 518083, P.R. China
| | - Quansheng Yang
- Center for RNA Molecular Biology and Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; McArdle Laboratory of Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Eckhard Jankowsky
- Center for RNA Molecular Biology and Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
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D'Heygère F, Schwartz A, Coste F, Castaing B, Boudvillain M. ATP-dependent motor activity of the transcription termination factor Rho from Mycobacterium tuberculosis. Nucleic Acids Res 2015; 43:6099-111. [PMID: 25999346 PMCID: PMC4499133 DOI: 10.1093/nar/gkv505] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/04/2015] [Indexed: 11/13/2022] Open
Abstract
The bacterial transcription termination factor Rho-a ring-shaped molecular motor displaying directional, ATP-dependent RNA helicase/translocase activity-is an interesting therapeutic target. Recently, Rho from Mycobacterium tuberculosis (MtbRho) has been proposed to operate by a mechanism uncoupled from molecular motor action, suggesting that the manner used by Rho to dissociate transcriptional complexes is not conserved throughout the bacterial kingdom. Here, however, we demonstrate that MtbRho is a bona fide molecular motor and directional helicase which requires a catalytic site competent for ATP hydrolysis to disrupt RNA duplexes or transcription elongation complexes. Moreover, we show that idiosyncratic features of the MtbRho enzyme are conferred by a large, hydrophilic insertion in its N-terminal 'RNA binding' domain and by a non-canonical R-loop residue in its C-terminal 'motor' domain. We also show that the 'motor' domain of MtbRho has a low apparent affinity for the Rho inhibitor bicyclomycin, thereby contributing to explain why M. tuberculosis is resistant to this drug. Overall, our findings support that, in spite of adjustments of the Rho motor to specific traits of its hosting bacterium, the basic principles of Rho action are conserved across species and could thus constitute pertinent screening criteria in high-throughput searches of new Rho inhibitors.
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Affiliation(s)
- François D'Heygère
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France Ecole doctorale Santé, Sciences Biologiques et Chimie du Vivant (ED 549), Université d'Orléans, Orléans, France
| | - Annie Schwartz
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Franck Coste
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Bertrand Castaing
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France ITP Sciences Biologiques & Chimie du Vivant, Université d'Orléans, Orléans, France
| | - Marc Boudvillain
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France ITP Sciences Biologiques & Chimie du Vivant, Université d'Orléans, Orléans, France
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35
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Abstract
In eukaryotic organisms, the orthologs of the DEAD-box RNA helicase Ded1p from yeast and DDX3 from human form a well-defined subfamily that is characterized by high sequence conservation in their helicase core and their N- and C- termini. Individual members of this Ded1/DDX3 subfamily perform multiple functions in RNA metabolism in both nucleus and cytoplasm. Ded1/DDX3 subfamily members have also been implicated in cellular signaling pathways and are targeted by diverse viruses. In this review, we discuss the considerable body of work on the biochemistry and biology of these proteins, including the recently discovered link of human DDX3 to tumorigenesis.
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Affiliation(s)
- Deepak Sharma
- Center for RNA Molecular Biology & Department of Biochemistry, School of Medicine, Case Western Reserve University , Cleveland, OH , USA
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36
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Kellner JN, Reinstein J, Meinhart A. Synergistic effects of ATP and RNA binding to human DEAD-box protein DDX1. Nucleic Acids Res 2015; 43:2813-28. [PMID: 25690890 PMCID: PMC4357711 DOI: 10.1093/nar/gkv106] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
RNA helicases of the DEAD-box protein family form the largest group of helicases. The human DEAD-box protein 1 (DDX1) plays an important role in tRNA and mRNA processing, is involved in tumor progression and is also hijacked by several virus families such as HIV-1 for replication and nuclear export. Although important in many cellular processes, the mechanism of DDX1′s enzymatic function is unknown. We have performed equilibrium titrations and transient kinetics to determine affinities for nucleotides and RNA. We find an exceptional tight binding of DDX1 to adenosine diphosphate (ADP), one of the strongest affinities observed for DEAD-box helicases. ADP binds tighter by three orders of magnitude when compared to adenosine triphosphate (ATP), arresting the enzyme in a potential dead-end ADP conformation under physiological conditions. We thus suggest that a nucleotide exchange factor leads to DDX1 recycling. Furthermore, we find a strong cooperativity in binding of RNA and ATP to DDX1 that is also reflected in ATP hydrolysis. We present a model in which either ATP or RNA binding alone can partially shift the equilibrium from an ‘open’ to a ‘closed’-state; this shift appears to be not further pronounced substantially even in the presence of both RNA and ATP as the low rate of ATP hydrolysis does not change.
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Affiliation(s)
- Julian N Kellner
- Department of Biomolecular Mechanisms, Max-Planck-Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Jochen Reinstein
- Department of Biomolecular Mechanisms, Max-Planck-Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Anton Meinhart
- Department of Biomolecular Mechanisms, Max-Planck-Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
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37
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Unzippers, resolvers and sensors: a structural and functional biochemistry tale of RNA helicases. Int J Mol Sci 2015; 16:2269-93. [PMID: 25622248 PMCID: PMC4346836 DOI: 10.3390/ijms16022269] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 12/28/2022] Open
Abstract
The centrality of RNA within the biological world is an irrefutable fact that currently attracts increasing attention from the scientific community. The panoply of functional RNAs requires the existence of specific biological caretakers, RNA helicases, devoted to maintain the proper folding of those molecules, resolving unstable structures. However, evolution has taken advantage of the specific position and characteristics of RNA helicases to develop new functions for these proteins, which are at the interface of the basic processes for transference of information from DNA to proteins. RNA helicases are involved in many biologically relevant processes, not only as RNA chaperones, but also as signal transducers, scaffolds of molecular complexes, and regulatory elements. Structural biology studies during the last decade, founded in X-ray crystallography, have characterized in detail several RNA-helicases. This comprehensive review summarizes the structural knowledge accumulated in the last two decades within this family of proteins, with special emphasis on the structure-function relationships of the most widely-studied families of RNA helicases: the DEAD-box, RIG-I-like and viral NS3 classes.
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38
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Ward WL, Russell R. Key points to consider when studying RNA remodeling by proteins. Methods Mol Biol 2015; 1259:1-16. [PMID: 25579576 DOI: 10.1007/978-1-4939-2214-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cellular RNAs depend on proteins for efficient folding to specific functional structures and for transitions between functional structures. This dependence arises from intrinsic properties of RNA structure. Specifically, RNAs possess stable local structure, largely in the form of helices, and they have abundant opportunities to form alternative helices and tertiary contacts and therefore to populate alternative structures. Proteins with RNA chaperone activity, either ATP-dependent or ATP-independent, can promote structural transitions by interacting with single-stranded RNA (ssRNA) to compete away partner interactions and then release ssRNA so that it can form new interactions. In this chapter we review the basic properties of RNA and the proteins that function as chaperones and remodelers. We then use these properties as a foundation to explore key points for the design and interpretation of experiments that probe RNA rearrangements and their acceleration by proteins.
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Affiliation(s)
- W Luke Ward
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, 105 E, 24th St. Stop A5300, Austin, TX, 78712, USA
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39
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DEAD-box protein CYT-19 is activated by exposed helices in a group I intron RNA. Proc Natl Acad Sci U S A 2014; 111:E2928-36. [PMID: 25002474 DOI: 10.1073/pnas.1404307111] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DEAD-box proteins are nonprocessive RNA helicases and can function as RNA chaperones, but the mechanisms of their chaperone activity remain incompletely understood. The Neurospora crassa DEAD-box protein CYT-19 is a mitochondrial RNA chaperone that promotes group I intron splicing and has been shown to resolve misfolded group I intron structures, allowing them to refold. Building on previous results, here we use a series of tertiary contact mutants of the Tetrahymena group I intron ribozyme to demonstrate that the efficiency of CYT-19-mediated unfolding of the ribozyme is tightly linked to global RNA tertiary stability. Efficient unfolding of destabilized ribozyme variants is accompanied by increased ATPase activity of CYT-19, suggesting that destabilized ribozymes provide more productive interaction opportunities. The strongest ATPase stimulation occurs with a ribozyme that lacks all five tertiary contacts and does not form a compact structure, and small-angle X-ray scattering indicates that ATPase activity tracks with ribozyme compactness. Further, deletion of three helices that are prominently exposed in the folded structure decreases the ATPase stimulation by the folded ribozyme. Together, these results lead to a model in which CYT-19, and likely related DEAD-box proteins, rearranges complex RNA structures by preferentially interacting with and unwinding exposed RNA secondary structure. Importantly, this mechanism could bias DEAD-box proteins to act on misfolded RNAs and ribonucleoproteins, which are likely to be less compact and more dynamic than their native counterparts.
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40
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Mallam AL, Sidote DJ, Lambowitz AM. Molecular insights into RNA and DNA helicase evolution from the determinants of specificity for a DEAD-box RNA helicase. eLife 2014; 3:e04630. [PMID: 25497230 PMCID: PMC4383044 DOI: 10.7554/elife.04630] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/10/2014] [Indexed: 01/07/2023] Open
Abstract
How different helicase families with a conserved catalytic 'helicase core' evolved to function on varied RNA and DNA substrates by diverse mechanisms remains unclear. In this study, we used Mss116, a yeast DEAD-box protein that utilizes ATP to locally unwind dsRNA, to investigate helicase specificity and mechanism. Our results define the molecular basis for the substrate specificity of a DEAD-box protein. Additionally, they show that Mss116 has ambiguous substrate-binding properties and interacts with all four NTPs and both RNA and DNA. The efficiency of unwinding correlates with the stability of the 'closed-state' helicase core, a complex with nucleotide and nucleic acid that forms as duplexes are unwound. Crystal structures reveal that core stability is modulated by family-specific interactions that favor certain substrates. This suggests how present-day helicases diversified from an ancestral core with broad specificity by retaining core closure as a common catalytic mechanism while optimizing substrate-binding interactions for different cellular functions.
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Affiliation(s)
- Anna L Mallam
- Institute for Cellular
and Molecular Biology, University of Texas at
Austin, Austin, United States,Department of Molecular
Biosciences, University of Texas at
Austin, Austin, United States
| | - David J Sidote
- Institute for Cellular
and Molecular Biology, University of Texas at
Austin, Austin, United States,Department of Molecular
Biosciences, University of Texas at
Austin, Austin, United States
| | - Alan M Lambowitz
- Institute for Cellular
and Molecular Biology, University of Texas at
Austin, Austin, United States,Department of Molecular
Biosciences, University of Texas at
Austin, Austin, United States,For correspondence:
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