1
|
Batista M, Langendijk-Genevaux P, Kwapisz M, Canal I, Phung DK, Plassart L, Capeyrou R, Moalic Y, Jebbar M, Flament D, Fichant G, Bouvier M, Clouet-d'Orval B. Evolutionary and functional insights into the Ski2-like helicase family in Archaea: a comparison of Thermococcales ASH-Ski2 and Hel308 activities. NAR Genom Bioinform 2024; 6:lqae026. [PMID: 38500564 PMCID: PMC10946056 DOI: 10.1093/nargab/lqae026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 02/19/2024] [Accepted: 02/27/2024] [Indexed: 03/20/2024] Open
Abstract
RNA helicases perform essential housekeeping and regulatory functions in all domains of life by binding and unwinding RNA molecules. The Ski2-like proteins are primordial helicases that play an active role in eukaryotic RNA homeostasis pathways, with multiple homologs having specialized functions. The significance of the expansion and diversity of Ski2-like proteins in Archaea, the third domain of life, has not yet been established. Here, by studying the phylogenetic diversity of Ski2-like helicases among archaeal genomes and the enzymatic activities of those in Thermococcales, we provide further evidence of the function of this protein family in archaeal metabolism of nucleic acids. We show that, in the course of evolution, ASH-Ski2 and Hel308-Ski2, the two main groups of Ski2-like proteins, have diverged in their biological functions. Whereas Hel308 has been shown to mainly act on DNA, we show that ASH-Ski2, previously described to be associated with the 5'-3' aRNase J exonuclease, acts on RNA by supporting an efficient annealing activity, but also an RNA unwinding with a 3'-5' polarity. To gain insights into the function of Ski2, we also analyse the transcriptome of Thermococcus barophilus ΔASH-Ski2 mutant strain and provide evidence of the importance of ASH-Ski2 in cellular metabolism pathways related to translation.
Collapse
Affiliation(s)
- Manon Batista
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | | | - Marta Kwapisz
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Isabelle Canal
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Duy Khanh Phung
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Laura Plassart
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Régine Capeyrou
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Yann Moalic
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, F-29280 Plouzané, France
| | - Mohamed Jebbar
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, F-29280 Plouzané, France
| | - Didier Flament
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, F-29280 Plouzané, France
| | - Gwennaele Fichant
- LMGM, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Marie Bouvier
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Béatrice Clouet-d'Orval
- MCD, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| |
Collapse
|
2
|
Van Gundy T, Patel D, Bowler BE, Rothfuss MT, Hall AJ, Davies C, Hall LS, Drecktrah D, Marconi RT, Samuels DS, Lybecker MC. c-di-GMP regulates activity of the PlzA RNA chaperone from the Lyme disease spirochete. Mol Microbiol 2023; 119:711-727. [PMID: 37086029 PMCID: PMC10330241 DOI: 10.1111/mmi.15066] [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: 04/03/2023] [Revised: 04/09/2023] [Accepted: 04/10/2023] [Indexed: 04/23/2023]
Abstract
PlzA is a c-di-GMP-binding protein crucial for adaptation of the Lyme disease spirochete Borrelia (Borreliella) burgdorferi during its enzootic life cycle. Unliganded apo-PlzA is important for vertebrate infection, while liganded holo-PlzA is important for survival in the tick; however, the biological function of PlzA has remained enigmatic. Here, we report that PlzA has RNA chaperone activity that is inhibited by c-di-GMP binding. Holo- and apo-PlzA bind RNA and accelerate RNA annealing, while only apo-PlzA can strand displace and unwind double-stranded RNA. Guided by the crystal structure of PlzA, we identified several key aromatic amino acids protruding from the N- and C-terminal domains that are required for RNA-binding and unwinding activity. Our findings illuminate c-di-GMP as a switch controlling the RNA chaperone activity of PlzA, and we propose that complex RNA-mediated modulatory mechanisms allow PlzA to regulate gene expression during both the vector and host phases of the B. burgdorferi life cycle.
Collapse
Affiliation(s)
- Taylor Van Gundy
- Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Center for Disease Control and Prevention, Fort Collins, CO 80521, USA
| | - Dhara Patel
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Bruce E. Bowler
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT 59812, USA
- Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
| | - Michael T. Rothfuss
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT 59812, USA
| | - Allie J. Hall
- Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Center for Disease Control and Prevention, Fort Collins, CO 80521, USA
| | - Christopher Davies
- Department of Biochemistry and Molecular Biology, University of Southern Alabama, Mobile, AL 36688, USA
| | - Laura S. Hall
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Dan Drecktrah
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Richard T. Marconi
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - D. Scott Samuels
- Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, USA
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Meghan C. Lybecker
- Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Center for Disease Control and Prevention, Fort Collins, CO 80521, USA
- Department of Biology, University of Colorado, 1420 Austin Bluffs Parkway, Colorado Springs CO 80917, USA
| |
Collapse
|
3
|
Zaharias S, Zhang Z, Davis K, Fargason T, Cashman D, Yu T, Zhang J. Intrinsically disordered electronegative clusters improve stability and binding specificity of RNA-binding proteins. J Biol Chem 2021; 297:100945. [PMID: 34246632 PMCID: PMC8348266 DOI: 10.1016/j.jbc.2021.100945] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/28/2021] [Accepted: 07/07/2021] [Indexed: 11/25/2022] Open
Abstract
RNA-binding proteins play crucial roles in various cellular functions and contain abundant disordered protein regions. The disordered regions in RNA-binding proteins are rich in repetitive sequences, such as poly-K/R, poly-N/Q, poly-A, and poly-G residues. Our bioinformatic analysis identified a largely neglected repetitive sequence family we define as electronegative clusters (ENCs) that contain acidic residues and/or phosphorylation sites. The abundance and length of ENCs exceed other known repetitive sequences. Despite their abundance, the functions of ENCs in RNA-binding proteins are still elusive. To investigate the impacts of ENCs on protein stability, RNA-binding affinity, and specificity, we selected one RNA-binding protein, the ribosomal biogenesis factor 15 (Nop15), as a model. We found that the Nop15 ENC increases protein stability and inhibits nonspecific RNA binding, but minimally interferes with specific RNA binding. To investigate the effect of ENCs on sequence specificity of RNA binding, we grafted an ENC to another RNA-binding protein, Ser/Arg-rich splicing factor 3. Using RNA Bind-n-Seq, we found that the engineered ENC inhibits disparate RNA motifs differently, instead of weakening all RNA motifs to the same extent. The motif site directly involved in electrostatic interaction is more susceptible to the ENC inhibition. These results suggest that one of functions of ENCs is to regulate RNA binding via electrostatic interaction. This is consistent with our finding that ENCs are also overrepresented in DNA-binding proteins, whereas underrepresented in halophiles, in which nonspecific nucleic acid binding is inhibited by high concentrations of salts.
Collapse
Affiliation(s)
- Steve Zaharias
- Department of Chemistry, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Zihan Zhang
- Department of Chemistry, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kenneth Davis
- Department of Chemistry, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Talia Fargason
- Department of Chemistry, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Derek Cashman
- Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee, USA
| | - Tao Yu
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota, USA
| | - Jun Zhang
- Department of Chemistry, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA.
| |
Collapse
|
4
|
Ali A, Mishra R, Kaur H, Chandra Banerjea A. HIV-1 Tat: An update on transcriptional and non-transcriptional functions. Biochimie 2021; 190:24-35. [PMID: 34242726 DOI: 10.1016/j.biochi.2021.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/24/2021] [Accepted: 07/01/2021] [Indexed: 01/05/2023]
Abstract
Over the past decades, much have been learned about HIV-1 virus and its molecular strategies for pathogenesis. However, HIV-1 still remains an enigmatic virus, particularly because of its unique proteins. Establishment of latency and reactivation is still a puzzling question and various temporal and spatial dynamics between HIV-1 proteins itself have given us new way of thinking about its pathogenesis. HIV-1 replication depends on Tat which is a small unstructured protein and subjected to various post-translational modifications for its myriad of functions. HIV-1 Tat protein modulates the functions of various strategic cellular pathways like proteasomal machinery and inflammatory pathways to aid in HIV-1 pathogenesis. Many of the recent findings have shown that Tat is associated with exosomes, cleared from HIV-1 infected cells through its degradation by diverse routes ranging from lysosomal to proteasomal pathways. HIV-1 Tat was also found to be associated with other HIV-1 proteins including Vpr, Nef, Nucleocapsid (NC) and Rev. Interaction of Tat with Vpr and Nef increases its transactivation function, whereas, interaction of Tat with NC or Rev leads to Tat protein degradation and hence suppression of Tat functions. Research in the recent years has established that Tat is not only important for HIV-1 promoter transactivation and virus replication but also modulating multiple cellular and molecular functions leading to HIV-1 pathogenicity. In this review we discussed various transcriptional and non-transcriptional HIV-1 Tat functions which modulate host cell metabolism during HIV-1 pathogenesis.
Collapse
Affiliation(s)
- Amjad Ali
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, 01605, USA.
| | - Ritu Mishra
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Harsimrut Kaur
- Department of Chemistry and Biochemistry, School of Basic Sciences and Research, Sharda University, Knowledge Park III, Greater Noida, Uttar Pradesh, 201310, India.
| | - Akhil Chandra Banerjea
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| |
Collapse
|
5
|
Yong XE, Palur VR, Anand GS, Wohland T, Sharma KK. Dengue virus 2 capsid protein chaperones the strand displacement of 5'-3' cyclization sequences. Nucleic Acids Res 2021; 49:5832-5844. [PMID: 34037793 PMCID: PMC8191770 DOI: 10.1093/nar/gkab379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 01/02/2023] Open
Abstract
By virtue of its chaperone activity, the capsid protein of dengue virus strain 2 (DENV2C) promotes nucleic acid structural rearrangements. However, the role of DENV2C during the interaction of RNA elements involved in stabilizing the 5′-3′ panhandle structure of DENV RNA is still unclear. Therefore, we determined how DENV2C affects structural functionality of the capsid-coding region hairpin element (cHP) during annealing and strand displacement of the 9-nt cyclization sequence (5CS) and its complementary 3CS. cHP has two distinct functions: a role in translation start codon selection and a role in RNA synthesis. Our results showed that cHP impedes annealing between 5CS and 3CS. Although DENV2C does not modulate structural functionality of cHP, it accelerates annealing and specifically promotes strand displacement of 3CS during 5′-3′ panhandle formation. Furthermore, DENV2C exerts its chaperone activity by favouring one of the active conformations of cHP. Based on our results, we propose mechanisms for annealing and strand displacement involving cHP. Thus, our results provide mechanistic insights into how DENV2C regulates RNA synthesis by modulating essential RNA elements in the capsid-coding region, that in turn allow for DENV replication.
Collapse
Affiliation(s)
- Xin Ee Yong
- NUS Graduate School Integrative Sciences and Engineering Programme, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore.,Centre for Bioimaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117557, Singapore
| | - V Raghuvamsi Palur
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Ganesh S Anand
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Thorsten Wohland
- Centre for Bioimaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117557, Singapore.,Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Kamal K Sharma
- Centre for Bioimaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117557, Singapore.,Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| |
Collapse
|
6
|
Real-Time Fluorescence-Based Approaches to Disentangle Mechanisms of a Protein's RNA Chaperone Activity. Methods Mol Biol 2020. [PMID: 31889252 DOI: 10.1007/978-1-0716-0231-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
RNA-binding proteins with an RNA chaperone activity exert either one or both of the following catalytic activities: (1) RNA annealing, i.e., the protein supports intra- as well as intermolecular RNA-RNA interactions and (2) strand displacement, i.e., the protein mediates the exchange of individual strands of a preexisting RNA duplex. To discriminate and further characterize these activities, it requires defined assay systems. These are based on entirely or partially complementary RNA oligonucleotides that are labeled with fluorescent and/or quencher dyes. The non-catalyzed and the protein-supported associations of the RNA molecules are followed by a real-time fluorescence resonance energy transfer (FRET) system. By site-specific modification of the RNAs or the protein, the substrate- and protein-specific parameters of the RNA chaperone activity can be explored and identified.In this chapter, we present strategies on the design of labeled RNA molecules to be used to characterize the activities of an RNA-binding protein and explain how to monitor progress curves of RNA annealing and strand displacement reactions in single cuvette or well-plate scales. We provide sets of equations and models to determine and analyze different types of reactions, e.g., by calculation of first- and second-order rate constants. Likewise, we demonstrate how to exploit these simple experimental setups to elucidate elementary principles of the reaction mechanisms performed by the protein of interest by applying basic kinetic applications, such as ARRHENIUS and linear free energy relationship analyses. These approaches will be explained by providing example plots and graphs from experiments investigating the RNA chaperone activities of the RNA-binding proteins NF90-NF45 and AUF1 p45.
Collapse
|
7
|
Qureshi NS, Bains JK, Sreeramulu S, Schwalbe H, Fürtig B. Conformational switch in the ribosomal protein S1 guides unfolding of structured RNAs for translation initiation. Nucleic Acids Res 2019; 46:10917-10929. [PMID: 30124944 PMCID: PMC6237739 DOI: 10.1093/nar/gky746] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/03/2018] [Indexed: 12/19/2022] Open
Abstract
Initiation of bacterial translation requires that the ribosome-binding site in mRNAs adopts single-stranded conformations. In Gram-negative bacteria the ribosomal protein S1 (rS1) is a key player in resolving of structured elements in mRNAs. However, the exact mechanism of how rS1 unfolds persistent secondary structures in the translation initiation region (TIR) is still unknown. Here, we show by NMR spectroscopy that Vibrio vulnificus rS1 displays a unique architecture of its mRNA-binding domains, where domains D3 and D4 provide the mRNA-binding platform and cover the nucleotide binding length of the full-length rS1. D5 significantly increases rS1’s chaperone activity, although it displays structural heterogeneity both in isolation and in presence of the other domains, albeit to varying degrees. The heterogeneity is induced by the switch between the two equilibrium conformations and is triggered by an order-to-order transition of two mutually exclusive secondary structures (β-strand-to-α-helix) of the ‘AERERI’ sequence. The conformational switching is exploited for melting of structured 5′-UTR’s, as the conformational heterogeneity of D5 can compensate the entropic penalty of complex formation. Our data thus provides a detailed understanding of the intricate coupling of protein and RNA folding dynamics enabling translation initiation of structured mRNAs.
Collapse
Affiliation(s)
- Nusrat Shahin Qureshi
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-Universität, Frankfurt am Main, Hessen 60438, Germany
| | - Jasleen Kaur Bains
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-Universität, Frankfurt am Main, Hessen 60438, Germany
| | - Sridhar Sreeramulu
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-Universität, Frankfurt am Main, Hessen 60438, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-Universität, Frankfurt am Main, Hessen 60438, Germany
| | - Boris Fürtig
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-Universität, Frankfurt am Main, Hessen 60438, Germany
| |
Collapse
|
8
|
Meyer A, Golbik RP, Sänger L, Schmidt T, Behrens SE, Friedrich S. The RGG/RG motif of AUF1 isoform p45 is a key modulator of the protein's RNA chaperone and RNA annealing activities. RNA Biol 2019; 16:960-971. [PMID: 30951406 DOI: 10.1080/15476286.2019.1602438] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The RNA-binding protein AUF1 regulates post-transcriptional gene expression by affecting the steady state and translation levels of numerous target RNAs. Remodeling of RNA structures by the largest isoform AUF1 p45 was recently demonstrated in the context of replicating RNA viruses, and involves two RNA remodeling activities, i.e. an RNA chaperone and an RNA annealing activity. AUF1 contains two non-identical RNA recognition motifs (RRM) and one RGG/RG motif located in the C-terminus. In order to determine the functional significance of each motif to AUF1's RNA-binding and remodeling activities we performed a comprehensive mutagenesis study and characterized the wildtype AUF1, and several variants thereof. We demonstrate that each motif contributes to efficient RNA binding and remodeling by AUF1 indicating a tight cooperation of the RRMs and the RGG/RG motif. Interestingly, the data identify two distinct roles for the arginine residues of the RGG/RG motif for each RNA remodeling activity. First, arginine-mediated stacking interactions promote AUF1's helix-destabilizing RNA chaperone activity. Second, the electropositive character of the arginine residues is the major driving force for the RNA annealing activity. Thus, we provide the first evidence that arginine residues of an RGG/RG motif contribute to the mechanism of RNA annealing and RNA chaperoning.
Collapse
Affiliation(s)
- Alexandra Meyer
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Ralph P Golbik
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Lennart Sänger
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Tobias Schmidt
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Sven-Erik Behrens
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Susann Friedrich
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| |
Collapse
|
9
|
Patwardhan NN, Cai Z, Newson CN, Hargrove AE. Fluorescent peptide displacement as a general assay for screening small molecule libraries against RNA. Org Biomol Chem 2019; 17:1778-1786. [PMID: 30468226 DOI: 10.1039/c8ob02467g] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A prominent hurdle in developing small molecule probes against RNA is the relative scarcity of general screening methods. In this study, we demonstrate the application of a fluorescent peptide displacement assay to screen small molecule probes against four different RNA targets. The designed experimental protocol combined with statistical analysis provides a fast and convenient method to simultaneously evaluate small molecule libraries against different RNA targets and classify them based on affinity and selectivity patterns.
Collapse
Affiliation(s)
- Neeraj N Patwardhan
- Department of Chemistry, 124 Science Drive, Box 90346, Durham, NC 27708, USA.
| | | | | | | |
Collapse
|
10
|
Schmidt T, Friedrich S, Golbik RP, Behrens SE. NF90-NF45 is a selective RNA chaperone that rearranges viral and cellular riboswitches: biochemical analysis of a virus host factor activity. Nucleic Acids Res 2017; 45:12441-12454. [PMID: 29040738 PMCID: PMC5716087 DOI: 10.1093/nar/gkx931] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/10/2017] [Indexed: 01/28/2023] Open
Abstract
The heterodimer NF90-NF45 is an RNA-binding protein complex that modulates the expression of various cellular mRNAs on the post-transcriptional level. Furthermore, it acts as a host factor that supports the replication of several RNA viruses. The molecular mechanisms underlying these activities have yet to be elucidated. Recently, we showed that the RNA-binding capabilities and binding specificity of NF90 considerably improves when it forms a complex with NF45. Here, we demonstrate that NF90 has a substrate-selective RNA chaperone activity (RCA) involving RNA annealing and strand displacement activities. The mechanism of the NF90-catalyzed RNA annealing was elucidated to comprise a combination of 'matchmaking' and compensation of repulsive charges, which finally results in the population of dsRNA products. Heterodimer formation with NF45 enhances 'matchmaking' of complementary ssRNAs and substantially increases the efficiency of NF90's RCA. During investigations of the relevance of the NF90-NF45 RCA, the complex was shown to stimulate the first step in the RNA replication process of hepatitis C virus (HCV) in vitro and to stabilize a regulatory element within the mRNA of vascular endothelial growth factor (VEGF) by protein-guided changes of the RNAs' structures. Thus, our study reveals how the intrinsic properties of an RNA-binding protein determine its biological activities.
Collapse
Affiliation(s)
- Tobias Schmidt
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
- To whom correspondence should be addressed. Tel: +49 3455 5249 60; Fax: +49 3455 5273 87; . Correspondence may also be addressed to Tobias Schmidt.
| | - Susann Friedrich
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
| | - Ralph Peter Golbik
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
- To whom correspondence should be addressed. Tel: +49 3455 5249 60; Fax: +49 3455 5273 87; . Correspondence may also be addressed to Tobias Schmidt.
| |
Collapse
|
11
|
A mutant tat protein inhibits HIV-1 reverse transcription by targeting the reverse transcription complex. J Virol 2015; 89:4827-36. [PMID: 25673710 DOI: 10.1128/jvi.03440-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 02/03/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED Previously, we reported that a mutant of Tat referred to as Nullbasic inhibits HIV-1 reverse transcription although the mechanism of action is unknown. Here we show that Nullbasic is a reverse transcriptase (RT) binding protein that targets the reverse transcription complex rather than directly inhibiting RT activity. An interaction between Nullbasic and RT was observed by using coimmunoprecipitation and pulldown assays, and a direct interaction was measured by using a biolayer interferometry assay. Mixtures of recombinant 6×His-RT and Nullbasic-FLAG-V5-6×His at molar ratios of up to 1:20,000 did not inhibit RT activity in standard homopolymer primer template assays. An analysis of virus made by cells that coexpressed Nullbasic showed that Nullbasic copurified with virus particles, indicating that it was a virion protein. In addition, analysis of reverse transcription complexes (RTCs) isolated from cells infected with wild type or Nullbasic-treated HIV-1 showed that Nullbasic reduced the levels of viral DNA in RTC fractions. In addition, a shift in the distribution of viral DNA and CAp24 to less-dense non-RTC fractions was observed, indicating that RTC activity from Nullbasic-treated virus was impaired. Further analysis showed that viral cores isolated from Nullbasic-treated HIV undergo increased disassembly in vitro compared to untreated HIV-1. To our knowledge, this is the first description of an antiviral protein that inhibits reverse transcription by targeting the RTC and affecting core stability. IMPORTANCE HIV-1 infection is treated by using combinations of antiretroviral drugs that target independent steps of virus replication. A newly described antiviral protein called Nullbasic can also inhibit a combination of different steps in virus replication (transcription, reverse transcription, and Rev-mediated viral mRNA transport), although the precise mechanism of action is unknown. This study shows that Nullbasic can inhibit reverse transcription by binding to the viral enzyme called reverse transcriptase, which results in accelerated uncoating of the viral core and instability of the viral apparatus called the reverse transcription complex (RTC). This unique antiviral activity may inform development of other RTC inhibitors, as well as providing a unique investigative tool for dissecting the RTC cellular composition.
Collapse
|
12
|
Boudier C, Humbert N, Chaminade F, Chen Y, de Rocquigny H, Godet J, Mauffret O, Fossé P, Mély Y. Dynamic interactions of the HIV-1 Tat with nucleic acids are critical for Tat activity in reverse transcription. Nucleic Acids Res 2013; 42:1065-78. [PMID: 24153111 PMCID: PMC3902927 DOI: 10.1093/nar/gkt934] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The HIV-1 transactivator of transcription (Tat) protein is thought to stimulate reverse transcription (RTion). The Tat protein and, more specifically, its (44–61) domain were recently shown to promote the annealing of complementary DNA sequences representing the HIV-1 transactivation response element TAR, named dTAR and cTAR, that plays a key role in RTion. Moreover, the kinetic mechanism of the basic Tat(44–61) peptide in this annealing further revealed that this peptide constitutes a representative nucleic acid annealer. To further understand the structure–activity relationships of this highly conserved domain, we investigated by electrophoresis and fluorescence approaches the binding and annealing properties of various Tat(44–61) mutants. Our data showed that the Tyr47 and basic residues of the Tat(44–61) domain were instrumental for binding to cTAR through stacking and electrostatic interactions, respectively, and promoting its annealing with dTAR. Furthermore, the annealing efficiency of the mutants clearly correlates with their ability to rapidly associate and dissociate the complementary oligonucleotides and to promote RTion. Thus, transient and dynamic nucleic acid interactions likely constitute a key mechanistic component of annealers and the role of Tat in the late steps of RTion. Finally, our data suggest that Lys50 and Lys51 acetylation regulates Tat activity in RTion.
Collapse
Affiliation(s)
- Christian Boudier
- Laboratoire de Biophotonique et Pharmacologie, UMR-CNRS 7213, Faculté de Pharmacie, Université de Strasbourg, Illkirch 67401, France and Laboratoire de Biologie et Pharmacologie Appliquée, UMR-CNRS 8113, Ecole Normale Supérieure de Cachan, Cachan 94235, France
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Stampfl S, Doetsch M, Beich-Frandsen M, Schroeder R. Characterization of the kinetics of RNA annealing and strand displacement activities of the E. coli DEAD-box helicase CsdA. RNA Biol 2013; 10:149-56. [PMID: 23291905 PMCID: PMC3590231 DOI: 10.4161/rna.23475] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
CsdA is one of five E. coli DEAD-box helicases and as a cold-shock protein assists RNA structural remodeling at low temperatures. The helicase has been shown to catalyze duplex unwinding in an ATP-dependent way and accelerate annealing of complementary RNAs, but detailed kinetic analyses are missing. Therefore, we performed kinetic measurements using a coupled annealing and strand displacement assay with high temporal resolution to analyze how CsdA balances the two converse activities. We furthermore tested the hypothesis that the unwinding activity of DEAD-box helicases is largely determined by the substrate’s thermodynamic stability using full-length CsdA and a set of RNAs with constant length, but increasing GC content. The rate constants for strand displacement did indeed decrease with increasing duplex stability, with a calculated free energy between -31.3 and -40 kcal/mol being the limit for helix unwinding. Thus, our data generally support the above hypothesis, showing that for CsdA substrate thermal stability is an important rate limiting factor.
Collapse
Affiliation(s)
- Sabine Stampfl
- Max F. Perutz Laboratories, Department for Biochemistry, Vienna, Austria
| | | | | | | |
Collapse
|
14
|
Ivanyi-Nagy R, Darlix JL. Reprint of: Core protein-mediated 5'-3' annealing of the West Nile virus genomic RNA in vitro. Virus Res 2012; 169:448-57. [PMID: 23022255 PMCID: PMC7172194 DOI: 10.1016/j.virusres.2012.09.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/08/2012] [Accepted: 05/08/2012] [Indexed: 12/21/2022]
Abstract
Genome cyclization through conserved RNA sequences located in the 5' and 3' terminal regions of flavivirus genomic RNA is essential for virus replication. Although the role of various cis-acting RNA elements in panhandle formation is well characterized, almost nothing is known about the potential contribution of protein cofactors to viral RNA cyclization. Proteins with nucleic acid chaperone activities are encoded by many viruses (e.g., retroviruses, coronaviruses) to facilitate RNA structural rearrangements and RNA-RNA interactions during the viral replicative cycle. Since the core protein of flaviviruses is also endowed with potent RNA chaperone activities, we decided to examine the effect of West Nile virus (WNV) core on 5'-3' genomic RNA annealing in vitro. Core protein binding resulted in a dramatic, dose-dependent increase in 5'-3' complex formation. Mutations introduced in either the UAR (upstream AUG region) or CS (conserved sequence) elements of the viral RNA diminished core protein-dependent annealing, while compensatory mutations restored the 5'-3' RNA interaction. The activity responsible for stimulating RNA annealing was mapped to the C-terminal RNA-binding region of WNV core protein. These results indicate that core protein - besides its function in viral particle formation - might be involved in the regulation of flavivirus genomic RNA cyclization, and thus virus replication.
Collapse
Affiliation(s)
- Roland Ivanyi-Nagy
- LaboRetro, INSERM U758, Ecole Normale Supérieure de Lyon, IFR128 Biosciences Lyon-Gerland, 46 allée d'Italie, 69364 Lyon, France
| | | |
Collapse
|
15
|
Doetsch M, Stampfl S, Fürtig B, Beich-Frandsen M, Saxena K, Lybecker M, Schroeder R. Study of E. coli Hfq's RNA annealing acceleration and duplex destabilization activities using substrates with different GC-contents. Nucleic Acids Res 2012; 41:487-97. [PMID: 23104381 PMCID: PMC3592463 DOI: 10.1093/nar/gks942] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Folding of RNA molecules into their functional three-dimensional structures is often supported by RNA chaperones, some of which can catalyse the two elementary reactions helix disruption and helix formation. Hfq is one such RNA chaperone, but its strand displacement activity is controversial. Whereas some groups found Hfq to destabilize secondary structures, others did not observe such an activity with their RNA substrates. We studied Hfq’s activities using a set of short RNAs of different thermodynamic stabilities (GC-contents from 4.8% to 61.9%), but constant length. We show that Hfq’s strand displacement as well as its annealing activity are strongly dependent on the substrate’s GC-content. However, this is due to Hfq’s preferred binding of AU-rich sequences and not to the substrate’s thermodynamic stability. Importantly, Hfq catalyses both annealing and strand displacement with comparable rates for different substrates, hinting at RNA strand diffusion and annealing nucleation being rate-limiting for both reactions. Hfq’s strand displacement activity is a result of the thermodynamic destabilization of the RNA through preferred single-strand binding whereas annealing acceleration is independent from Hfq’s thermodynamic influence. Therefore, the two apparently disparate activities annealing acceleration and duplex destabilization are not in energetic conflict with each other.
Collapse
Affiliation(s)
- Martina Doetsch
- Department for Biochemistry, Max F Perutz Laboratories, Dr-Bohrgasse 9, 1030 Vienna, Austria
| | | | | | | | | | | | | |
Collapse
|
16
|
de Almeida Ribeiro E, Beich-Frandsen M, Konarev PV, Shang W, Večerek B, Kontaxis G, Hämmerle H, Peterlik H, Svergun DI, Bläsi U, Djinović-Carugo K. Structural flexibility of RNA as molecular basis for Hfq chaperone function. Nucleic Acids Res 2012; 40:8072-84. [PMID: 22718981 PMCID: PMC3439903 DOI: 10.1093/nar/gks510] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/05/2012] [Accepted: 05/09/2012] [Indexed: 12/22/2022] Open
Abstract
In enteric bacteria, many small regulatory RNAs (sRNAs) associate with the RNA chaperone host factor Q (Hfq) and often require the protein for regulation of target mRNAs. Previous studies suggested that the hexameric Escherichia coli Hfq (Hfq(Ec)) binds sRNAs on the proximal site, whereas the distal site has been implicated in Hfq-mRNA interactions. Employing a combination of small angle X-ray scattering, nuclear magnetic resonance and biochemical approaches, we report the structural analysis of a 1:1 complex of Hfq(Ec) with a 34-nt-long subsequence of a natural substrate sRNA, DsrA (DsrA(34)). This sRNA is involved in post-transcriptional regulation of the E. coli rpoS mRNA encoding the stationary phase sigma factor RpoS. The molecular envelopes of Hfq(Ec) in complex with DsrA(34) revealed an overall asymmetric shape of the complex in solution with the protein maintaining its doughnut-like structure, whereas the extended DsrA(34) is flexible and displays an ensemble of different spatial arrangements. These results are discussed in terms of a model, wherein the structural flexibility of RNA ligands bound to Hfq stochastically facilitates base pairing and provides the foundation for the RNA chaperone function inherent to Hfq.
Collapse
Affiliation(s)
- Euripedes de Almeida Ribeiro
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Mads Beich-Frandsen
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Petr V. Konarev
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Weifeng Shang
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Branislav Večerek
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Georg Kontaxis
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Hermann Hämmerle
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Herwig Peterlik
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Dmitri I. Svergun
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Udo Bläsi
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria, EMBL-Hamburg c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria and Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
| |
Collapse
|
17
|
Ivanyi-Nagy R, Darlix JL. Core protein-mediated 5'-3' annealing of the West Nile virus genomic RNA in vitro. Virus Res 2012; 167:226-35. [PMID: 22652509 PMCID: PMC7172325 DOI: 10.1016/j.virusres.2012.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/08/2012] [Accepted: 05/08/2012] [Indexed: 01/17/2023]
Abstract
Genome cyclization through conserved RNA sequences located in the 5' and 3' terminal regions of flavivirus genomic RNA is essential for virus replication. Although the role of various cis-acting RNA elements in panhandle formation is well characterized, almost nothing is known about the potential contribution of protein cofactors to viral RNA cyclization. Proteins with nucleic acid chaperone activities are encoded by many viruses (e.g., retroviruses, coronaviruses) to facilitate RNA structural rearrangements and RNA-RNA interactions during the viral replicative cycle. Since the core protein of flaviviruses is also endowed with potent RNA chaperone activities, we decided to examine the effect of West Nile virus (WNV) core on 5'-3' genomic RNA annealing in vitro. Core protein binding resulted in a dramatic, dose-dependent increase in 5'-3' complex formation. Mutations introduced in either the UAR (upstream AUG region) or CS (conserved sequence) elements of the viral RNA diminished core protein-dependent annealing, while compensatory mutations restored the 5'-3' RNA interaction. The activity responsible for stimulating RNA annealing was mapped to the C-terminal RNA-binding region of WNV core protein. These results indicate that core protein - besides its function in viral particle formation - might be involved in the regulation of flavivirus genomic RNA cyclization, and thus virus replication.
Collapse
Key Words
- cs, conserved sequence
- dar, downstream aug region
- db, dumbbell-like structure
- denv, dengue virus
- jev, japanese encephalitis virus
- orf, open reading frame
- rdrp, rna-dependent rna polymerase
- sfrna, subgenomic flavivirus rna
- tbev, tick-borne encephalitis virus
- uar, upstream aug region
- utr, untranslated region
- wnv, west nile virus
- yfv, yellow fever virus
- west nile virus
- core protein
- flaviviruses
- viral replication
- genome cyclization
- rna chaperoning
Collapse
Affiliation(s)
| | - Jean-Luc Darlix
- LaboRetro, INSERM U758, Ecole Normale Supérieure de Lyon, IFR128 Biosciences Lyon-Gerland, 46 allée d’Italie, 69364 Lyon, France
| |
Collapse
|
18
|
Godet J, Boudier C, Humbert N, Ivanyi-Nagy R, Darlix JL, Mély Y. Comparative nucleic acid chaperone properties of the nucleocapsid protein NCp7 and Tat protein of HIV-1. Virus Res 2012; 169:349-60. [PMID: 22743066 PMCID: PMC7114403 DOI: 10.1016/j.virusres.2012.06.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022]
Abstract
RNA chaperones are proteins able to rearrange nucleic acid structures towards their most stable conformations. In retroviruses, the reverse transcription of the viral RNA requires multiple and complex nucleic acid rearrangements that need to be chaperoned. HIV-1 has evolved different viral-encoded proteins with chaperone activity, notably Tat and the well described nucleocapsid protein NCp7. We propose here an overview of the recent reports that examine and compare the nucleic acid chaperone properties of Tat and NCp7 during reverse transcription to illustrate the variety of mechanisms of action of the nucleic acid chaperone proteins.
Collapse
Affiliation(s)
- Julien Godet
- Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, UMR 7213 CNRS, Université de Strasbourg, 67401 Illkirch, France
| | | | | | | | | | | |
Collapse
|
19
|
Abstract
The RNA folding trajectory features numerous off-pathway folding traps, which represent conformations that are often equally as stable as the native functional ones. Therefore, the conversion between these off-pathway structures and the native correctly folded ones is the critical step in RNA folding. This process, referred to as RNA refolding, is slow, and is represented by a transition state that has a characteristic high free energy. Because this kinetically limiting process occurs in vivo, proteins (called RNA chaperones) have evolved that facilitate the (re)folding of RNA molecules. Here, we present an overview of how proteins interact with RNA molecules in order to achieve properly folded states. In this respect, the discrimination between static and transient interactions is crucial, as different proteins have evolved a multitude of mechanisms for RNA remodeling. For RNA chaperones that act in a sequence-unspecific manner and without the use of external sources of energy, such as ATP, transient RNA–protein interactions represent the basis of the mode of action. By presenting stretches of positively charged amino acids that are positioned in defined spatial configurations, RNA chaperones enable the RNA backbone, via transient electrostatic interactions, to sample a wider conformational space that opens the route for efficient refolding reactions.
Collapse
Affiliation(s)
- Martina Doetsch
- Department of Biochemistry and Molecular Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | | | | |
Collapse
|