1
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Turbant F, Machiels Q, Waeytens J, Wien F, Arluison V. The Amyloid Assembly of the Bacterial Hfq Is Lipid-Driven and Lipid-Specific. Int J Mol Sci 2024; 25:1434. [PMID: 38338713 PMCID: PMC10855545 DOI: 10.3390/ijms25031434] [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: 12/27/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Under specific conditions, some proteins can self-assemble into fibrillar structures called amyloids. Initially, these proteins were associated with neurodegenerative diseases in eucaryotes. Nevertheless, they have now been identified in the three domains of life. In bacteria, they are involved in diverse biological processes and are usually useful for the cell. For this reason, they are classified as "functional amyloids". In this work, we focus our analysis on a bacterial functional amyloid called Hfq. Hfq is a pleiotropic regulator that mediates several aspects of genetic expression, mainly via the use of small noncoding RNAs. Our previous work showed that Hfq amyloid-fibrils interact with membranes. This interaction influences Hfq amyloid structure formation and stability, but the specifics of the lipid on the dynamics of this process is unknown. Here, we show, using spectroscopic methods, how lipids specifically drive and modulate Hfq amyloid assembly or, conversely, its disassembly. The reported effects are discussed in light of the consequences for bacterial cell life.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, CEA Saclay, 91191 Gif-sur-Yvette, France;
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Quentin Machiels
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium; (Q.M.); (J.W.)
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium; (Q.M.); (J.W.)
- Unit of Pharmacognosy, Bioanalysis and Drug Discovery, Université Libre de Bruxelles, 1050 Bruxelles, Belgium
| | - Frank Wien
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, CEA Saclay, 91191 Gif-sur-Yvette, France;
- SDV Department, Université Paris Cité, 75006 Paris, France
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2
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Watkins D, Arya D. Models of Hfq interactions with small non-coding RNA in Gram-negative and Gram-positive bacteria. Front Cell Infect Microbiol 2023; 13:1282258. [PMID: 37942477 PMCID: PMC10628458 DOI: 10.3389/fcimb.2023.1282258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023] Open
Abstract
Hfq is required by many Gram-negative bacteria to chaperone the interaction between small non-coding RNA (sRNA) and mRNA to facilitate annealing. Conversely and despite the presence of Hfq in many Gram-positive bacteria, sRNAs in Gram-positive bacteria bind the mRNA target independent of Hfq. Details provided by the Hfq structures from both Gram-negative and Gram-positive bacteria have demonstrated that despite a conserved global structure of the protein, variations of residues on the binding surfaces of Hfq results in the recognition of different RNA sequences as well as the ability of Hfq to facilitate the annealing of the sRNA to the mRNA target. Additionally, a subset of Gram-negative bacteria has an extended C-terminal Domain (CTD) that has been shown to affect the stability of the Hfq hexamer and increase the rate of release of the annealed sRNA-mRNA product. Here we review the structures of Hfq and biochemical data that have defined the interactions of the Gram-negative and Gram-positive homologues to highlight the similarities and differences in the interactions with RNA. These interactions provided a deeper understanding of the how Hfq functions to facilitate the annealing of sRNA-mRNA, the selectivity of the interactions with RNA, and the role of the CTD of Hfq in the interactions with sRNA.
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Affiliation(s)
- Derrick Watkins
- Department of Math and Science, University of Tennessee Southern, Pulaski, TN, United States
| | - Dev Arya
- Laboratory for Medicinal Chemistry, Department of Chemistry, Clemson University, Clemson, SC, United States
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3
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Berbon M, Martinez D, Morvan E, Grélard A, Kauffmann B, Waeytens J, Wien F, Arluison V, Habenstein B. Hfq C-terminal region forms a β-rich amyloid-like motif without perturbing the N-terminal Sm-like structure. Commun Biol 2023; 6:1075. [PMID: 37865695 PMCID: PMC10590398 DOI: 10.1038/s42003-023-05462-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/13/2023] [Indexed: 10/23/2023] Open
Abstract
Hfq is a pleitropic actor that serves as stress response and virulence factor in the bacterial cell. To execute its multiple functions, Hfq assembles into symmetric torus-shaped hexamers. Extending outward from the hexameric core, Hfq presents a C-terminal region, described as intrinsically disordered in solution. Many aspects of the role and the structure of this region remain unclear. For instance, in its truncated form it can promote amyloid-like filament assembly. Here, we show that a minimal 11-residue motif at the C-terminal end of Hfq assembles into filaments with amyloid characteristics. Our data suggest that the full-length Hfq in its filamentous state contains a similar molecular fingerprint than that of the short β-strand peptide, and that the Sm-core structure is not affected by filament formation. Hfq proteins might thus co-exist in two forms in vivo, either as isolated, soluble hexamers or as self-assembled hexamers through amyloid-reminiscent interactions, modulating Hfq cellular functions.
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Affiliation(s)
- Mélanie Berbon
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France
| | - Denis Martinez
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France
| | - Estelle Morvan
- Univ. Bordeaux, CNRS, INSERM, IECB, UAR 3033, Pessac, France
| | - Axelle Grélard
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France
| | - Brice Kauffmann
- Univ. Bordeaux, CNRS, INSERM, IECB, UAR 3033, Pessac, France
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, Bruxelles, Belgique
| | - Frank Wien
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192, Gif-sur-Yvette, France
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, UMR12 CEA CNRS, CEA Saclay, 91191, Gif-sur-Yvette, France.
- Université de Paris Cité, UFR SDV, 75013, Paris, France.
| | - Birgit Habenstein
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, IECB, Pessac, France.
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4
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Turbant F, Waeytens J, Blache A, Esnouf E, Raussens V, Węgrzyn G, Achouak W, Wien F, Arluison V. Interactions and Insertion of Escherichia coli Hfq into Outer Membrane Vesicles as Revealed by Infrared and Orientated Circular Dichroism Spectroscopies. Int J Mol Sci 2023; 24:11424. [PMID: 37511182 PMCID: PMC10379585 DOI: 10.3390/ijms241411424] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
The possible carrier role of Outer Membrane Vesicles (OMVs) for small regulatory noncoding RNAs (sRNAs) has recently been demonstrated. Nevertheless, to perform their function, these sRNAs usually need a protein cofactor called Hfq. In this work we show, by using a combination of infrared and circular dichroism spectroscopies, that Hfq, after interacting with the inner membrane, can be translocated into the periplasm, and then be exported in OMVs, with the possibility to be bound to sRNAs. Moreover, we provide evidence that Hfq interacts with and is inserted into OMV membranes, suggesting a role for this protein in the release of sRNA outside the vesicle. These findings provide clues to the mechanism of host-bacteria interactions which may not be defined solely by protein-protein and protein-outer membrane contacts, but also by the exchange of RNAs, and in particular sRNAs.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, 1050 Bruxelles, Belgium
| | - Anaïs Blache
- Lab of Microbial Ecology of the Rhizosphere, (LEMiRE), BIAM, CEA, CNRS, Aix Marseille University, 13115 Saint Paul Lez Durance, France
| | - Emeline Esnouf
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Vincent Raussens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, 1050 Bruxelles, Belgium
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Wafa Achouak
- Lab of Microbial Ecology of the Rhizosphere, (LEMiRE), BIAM, CEA, CNRS, Aix Marseille University, 13115 Saint Paul Lez Durance, France
| | - Frank Wien
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
- UFR Sciences du Vivant, Université Paris Cité, 75006 Paris, France
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5
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Cossa A, Trépout S, Wien F, Groen J, Le Brun E, Turbant F, Besse L, Pereiro E, Arluison V. Cryo soft X-ray tomography to explore Escherichia coli nucleoid remodeling by Hfq master regulator. J Struct Biol 2022; 214:107912. [PMID: 36283630 DOI: 10.1016/j.jsb.2022.107912] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 09/28/2022] [Accepted: 10/18/2022] [Indexed: 11/18/2022]
Abstract
The bacterial chromosomic DNA is packed within a membrane-less structure, the nucleoid, due to the association of DNA with proteins called Nucleoid Associated Proteins (NAPs). Among these NAPs, Hfq is one of the most intriguing as it plays both direct and indirect roles on DNA structure. Indeed, Hfq is best known to mediate post-transcriptional regulation by using small noncoding RNA (sRNA). Although Hfq presence in the nucleoid has been demonstrated for years, its precise role is still unclear. Recently, it has been shown in vitro that Hfq forms amyloid-like structures through its C-terminal region, hence belonging to the bridging family of NAPs. Here, using cryo soft X-ray tomography imaging of native unlabeled cells and using a semi-automatic analysis and segmentation procedure, we show that Hfq significantly remodels the Escherichia coli nucleoid. More specifically, Hfq influences nucleoid density especially during the stationary growth phase when it is more abundant. Our results indicate that Hfq could regulate nucleoid compaction directly via its interaction with DNA, but also at the post-transcriptional level via its interaction with RNAs. Taken together, our findings reveal a new role for this protein in nucleoid remodeling in vivo, that may serve in response to stress conditions and in adapting to changing environments.
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Affiliation(s)
- Antoine Cossa
- Institut Curie, Université PSL, CNRS UAR2016, Inserm US43, Université Paris-Saclay, Multimodal Imaging Center, 91400 Orsay, France; Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Sylvain Trépout
- Institut Curie, Université PSL, CNRS UAR2016, Inserm US43, Université Paris-Saclay, Multimodal Imaging Center, 91400 Orsay, France; Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, Victoria 3800, Australia.
| | - Frank Wien
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Johannes Groen
- Mistral Beamline, Alba Light Source, Cerdanyola del Valles, 08290 Barcelona, Spain
| | - Etienne Le Brun
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France; Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Laetitia Besse
- Institut Curie, Université PSL, CNRS UAR2016, Inserm US43, Université Paris-Saclay, Multimodal Imaging Center, 91400 Orsay, France
| | - Eva Pereiro
- Mistral Beamline, Alba Light Source, Cerdanyola del Valles, 08290 Barcelona, Spain
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France; Université Paris Cité, UFR Sciences du vivant, 75006 Paris cedex, France.
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6
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Turbant F, Waeytens J, Campidelli C, Bombled M, Martinez D, Grélard A, Habenstein B, Raussens V, Velez M, Wien F, Arluison V. Unraveling Membrane Perturbations Caused by the Bacterial Riboregulator Hfq. Int J Mol Sci 2022; 23:ijms23158739. [PMID: 35955871 PMCID: PMC9369112 DOI: 10.3390/ijms23158739] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 12/02/2022] Open
Abstract
Hfq is a pleiotropic regulator that mediates several aspects of bacterial RNA metabolism. The protein notably regulates translation efficiency and RNA decay in Gram-negative bacteria, usually via its interaction with small regulatory RNAs. Previously, we showed that the Hfq C-terminal region forms an amyloid-like structure and that these fibrils interact with membranes. The immediate consequence of this interaction is a disruption of the membrane, but the effect on Hfq structure was unknown. To investigate details of the mechanism of interaction, the present work uses different in vitro biophysical approaches. We show that the Hfq C-terminal region influences membrane integrity and, conversely, that the membrane specifically affects the amyloid assembly. The reported effect of this bacterial master regulator on membrane integrity is discussed in light of the possible consequence on small regulatory RNA-based regulation.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium
- Institut de Chimie Physique, CNRS UMR8000, Université Paris-Sud, Université Paris-Saclay, 91400 Orsay, France
| | - Camille Campidelli
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Marianne Bombled
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Denis Martinez
- Institute of Chemistry & Biology of Membranes & Nanoobjects (UMR5248 CBMN), University of Bordeaux, CNRS, Bordeaux INP, 33600 Pessac, France
| | - Axelle Grélard
- Institute of Chemistry & Biology of Membranes & Nanoobjects (UMR5248 CBMN), University of Bordeaux, CNRS, Bordeaux INP, 33600 Pessac, France
| | - Birgit Habenstein
- Institute of Chemistry & Biology of Membranes & Nanoobjects (UMR5248 CBMN), University of Bordeaux, CNRS, Bordeaux INP, 33600 Pessac, France
| | - Vincent Raussens
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, 1050 Bruxelles, Belgium
| | - Marisela Velez
- Instituto de Catálisis y Petroleoquímica, CSIC, c/Marie Curie, 2, Cantoblanco, E-28049 Madrid, Spain
| | - Frank Wien
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France
- Correspondence: (F.W.); (V.A.)
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
- UFR SDV, Université Paris Cité, 75006 Paris, France
- Correspondence: (F.W.); (V.A.)
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The Denaturant- and Mutation-Induced Disassembly of Pseudomonas aeruginosa Hexameric Hfq Y55W Mutant. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123821. [PMID: 35744948 PMCID: PMC9228748 DOI: 10.3390/molecules27123821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/10/2022] [Accepted: 06/11/2022] [Indexed: 11/17/2022]
Abstract
Although oligomeric proteins are predominant in cells, their folding is poorly studied at present. This work is focused on the denaturant- and mutation-induced disassembly of the hexameric mutant Y55W of the Qβ host factor (Hfq) from mesophilic Pseudomonas aeruginosa (Pae). Using intrinsic tryptophan fluorescence, dynamic light scattering (DLS), and high-performance liquid chromatography (HPLC), we show that the dissociation of Hfq Y55W occurs either under the effect of GuHCl or during the pre-denaturing transition, when the protein concentration is decreased, with both events proceeding through the accumulation of stable intermediate states. With an extremely low pH of 1.4, a low ionic strength, and decreasing protein concentration, the accumulated trimers and dimers turn into monomers. Also, we report on the structural features of monomeric Hfq resulting from a triple mutation (D9A/V43R/Y55W) within the inter-subunit surface of the protein. This globular and rigidly packed monomer displays a high thermostability and an oligomer-like content of the secondary structure, although its urea resistance is much lower.
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Synchrotron Radiation Circular Dichroism, a New Tool to Probe Interactions between Nucleic Acids Involved in the Control of ColE1-Type Plasmid Replication. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12052639] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Hfq is a bacterial master regulator which promotes the pairing of nucleic acids. Due to the high molecular weight of the complexes formed between nucleic acids and the amyloid form of the protein, it is difficult to analyze solely by a gel shift assay the complexes formed, as they all migrate at the same position in the gel. In addition, precise kinetics measurements are not possible using a gel shift assay. Here, we used a synchrotron-based biophysical approach, synchrotron radiation circular dichroism (SRCD), to probe the interaction of the Escherichia coli Hfq C-terminal amyloid region with nucleic acids involved in the control of ColE1-like plasmid replication. We observed that this C-terminal region of Hfq has an unexpected and significant effect on the annealing of nucleic acids involved in this process and, more importantly, on their alignment. Functional consequences of this newly discovered property of the Hfq amyloid region are discussed in terms of the biological significance of Hfq in the ColE1-type plasmid replication process and antibiotic resistance.
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Alipov AA, Lekontseva NV, Mikhailina AO, Fando MS, Tishchenko SV, Nikulin AD. Structure of a Mutant Form of Translation Regulator Hfq with the Extended Loop L4. CRYSTALLOGR REP+ 2021. [DOI: 10.1134/s1063774521050023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Turbant F, Wu P, Wien F, Arluison V. The Amyloid Region of Hfq Riboregulator Promotes DsrA: rpoS RNAs Annealing. BIOLOGY 2021; 10:biology10090900. [PMID: 34571778 PMCID: PMC8468756 DOI: 10.3390/biology10090900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/30/2021] [Accepted: 09/05/2021] [Indexed: 11/16/2022]
Abstract
Hfq is a bacterial RNA chaperone which promotes the pairing of small noncoding RNAs to target mRNAs, allowing post-transcriptional regulation. This RNA annealing activity has been attributed for years to the N-terminal region of the protein that forms a toroidal structure with a typical Sm-fold. Nevertheless, many Hfqs, including that of Escherichia coli, have a C-terminal region with unclear functions. Here we use a biophysical approach, Synchrotron Radiation Circular Dichroism (SRCD), to probe the interaction of the E. coli Hfq C-terminal amyloid region with RNA and its effect on RNA annealing. This C-terminal region of Hfq, which has been described to be dispensable for sRNA:mRNA annealing, has an unexpected and significant effect on this activity. The functional consequences of this novel property of the amyloid region of Hfq in relation to physiological stress are discussed.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France;
| | - Pengzhi Wu
- Department of Biology, ETH Zürich, 8093 Zürich, Switzerland;
| | - Frank Wien
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France
- Correspondence: (F.W.); or (V.A.); Tel.: +33-(0)169359665 (F.W.); +33-(0)169083282 (V.A.)
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France;
- UFR Sciences du Vivant, Université de Paris, 75006 Paris, France
- Correspondence: (F.W.); or (V.A.); Tel.: +33-(0)169359665 (F.W.); +33-(0)169083282 (V.A.)
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11
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Turbant F, Partouche D, El Hamoui O, Trépout S, Legoubey T, Wien F, Arluison V. Apomorphine Targets the Pleiotropic Bacterial Regulator Hfq. Antibiotics (Basel) 2021; 10:antibiotics10030257. [PMID: 33806663 PMCID: PMC8000489 DOI: 10.3390/antibiotics10030257] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/24/2021] [Accepted: 02/27/2021] [Indexed: 12/15/2022] Open
Abstract
Hfq is a bacterial regulator with key roles in gene expression. The protein notably regulates translation efficiency and RNA decay in Gram-negative bacteria, thanks to its binding to small regulatory noncoding RNAs. This property is of primary importance for bacterial adaptation and survival in hosts. Small RNAs and Hfq are, for instance, involved in the response to antibiotics. Previous work has shown that the E. coli Hfq C-terminal region (Hfq-CTR) self-assembles into an amyloid structure. It was also demonstrated that the green tea compound EpiGallo Catechin Gallate (EGCG) binds to Hfq-CTR amyloid fibrils and remodels them into nonamyloid structures. Thus, compounds that target the amyloid region of Hfq may be used as antibacterial agents. Here, we show that another compound that inhibits amyloid formation, apomorphine, may also serve as a new antibacterial. Our results provide an alternative in order to repurpose apomorphine, commonly used in the treatment of Parkinson’s disease, as an antibiotic to block bacterial adaptation to treat infections.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France; (F.T.); (D.P.); (T.L.)
| | - David Partouche
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France; (F.T.); (D.P.); (T.L.)
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
| | - Omar El Hamoui
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
| | - Sylvain Trépout
- Institut Curie, Inserm US43, and CNRS UMS2016, 91405 Orsay CEDEX, France;
| | - Théa Legoubey
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France; (F.T.); (D.P.); (T.L.)
| | - Frank Wien
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France;
- Correspondence: (F.W.); or (V.A.); Tel.: +33-(0)169359665 (F.W.); +33-(0)169083282 (V.A.)
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France; (F.T.); (D.P.); (T.L.)
- UFR Sciences du Vivant, Université de Paris, 75006 Paris CEDEX, France
- Correspondence: (F.W.); or (V.A.); Tel.: +33-(0)169359665 (F.W.); +33-(0)169083282 (V.A.)
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12
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Turbant F, Hamoui OE, Partouche D, Sandt C, Busi F, Wien F, Arluison V. Identification and characterization of the Hfq bacterial amyloid region DNA interactions. BBA ADVANCES 2021; 1:100029. [PMID: 37082015 PMCID: PMC10074921 DOI: 10.1016/j.bbadva.2021.100029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 11/18/2022] Open
Abstract
Nucleic acid amyloid proteins interactions have been observed in the past few years. These interactions often promote protein aggregation. Nevertheless, molecular basis and physiological consequences of these interactions are still poorly understood. Additionally, it is unknown whether the nucleic acid promotes the formation of self-assembly due to direct interactions or indirectly via sequences surrounding the amyloid region. Here we focus our attention on a bacterial amyloid, Hfq. This protein is a pleiotropic bacterial regulator that mediates many aspects of nucleic acids metabolism. The protein notably mediates mRNA stability and translation efficiency by using stress-related small non coding regulatory RNA. In addition, Hfq, thanks to its amyloid C-terminal region, binds and compacts DNA. A combination of experimental methodologies, including synchrotron radiation circular dichroism (SRCD), gel shift assay and infrared (FTIR) spectroscopy have been used to probe the interaction of Hfq C-terminal region with DNA. We clearly identify important amino acids in this region involved in DNA binding and polymerization properties. This allows to understand better how this bacterial amyloid interacts with DNA. Possible functional consequence to answer to stresses are discussed.
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Affiliation(s)
- Florian Turbant
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Omar El Hamoui
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192, Gif-sur-Yvette, France
| | - David Partouche
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192, Gif-sur-Yvette, France
| | - Christophe Sandt
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192, Gif-sur-Yvette, France
| | - Florent Busi
- Université de Paris, UFR Sciences du vivant, 75006 Paris cedex, France
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | - Frank Wien
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, 91192, Gif-sur-Yvette, France
- Corresponding author.
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
- Université de Paris, UFR Sciences du vivant, 75006 Paris cedex, France
- Corresponding author.
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13
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Crucial Role of the C-Terminal Domain of Hfq Protein in Genomic Instability. Microorganisms 2020; 8:microorganisms8101598. [PMID: 33080799 PMCID: PMC7603069 DOI: 10.3390/microorganisms8101598] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/10/2020] [Accepted: 10/13/2020] [Indexed: 01/25/2023] Open
Abstract
G-rich DNA repeats that can form G-quadruplex structures are prevalent in bacterial genomes and are frequently associated with regulatory regions of genes involved in virulence, antigenic variation, and antibiotic resistance. These sequences are also inherently mutagenic and can lead to changes affecting cell survival and adaptation. Transcription of the G-quadruplex-forming repeat (G3T)n in E. coli, when mRNA comprised the G-rich strand, promotes G-quadruplex formation in DNA and increases rates of deletion of G-quadruplex-forming sequences. The genomic instability of G-quadruplex repeats may be a source of genetic variability that can influence alterations and evolution of bacteria. The DNA chaperone Hfq is involved in the genetic instability of these G-quadruplex sequences. Inactivation of the hfq gene decreases the genetic instability of G-quadruplex, demonstrating that the genomic instability of this regulatory element can be influenced by the E. coli highly pleiotropic Hfq protein, which is involved in small noncoding RNA regulation pathways, and DNA organization and packaging. We have shown previously that the protein binds to and stabilizes these sequences, increasing rates of their genomic instability. Here, we extend this analysis to characterize the role of the C-terminal domain of Hfq protein in interaction with G-quadruplex structures. This allows to better understand the function of this specific region of the Hfq protein in genomic instability.
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14
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In Situ Characterization of Hfq Bacterial Amyloid: A Fourier-Transform Infrared Spectroscopy Study. Pathogens 2019; 8:pathogens8010036. [PMID: 30889801 PMCID: PMC6471401 DOI: 10.3390/pathogens8010036] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/11/2019] [Accepted: 03/13/2019] [Indexed: 12/18/2022] Open
Abstract
Hfq is a bacterial protein that regulates gene expression at the post-transcriptional level in Gram-negative bacteria. We have previously shown that Escherichia coli Hfq protein, and more precisely its C-terminal region (CTR), self-assembles into an amyloid-like structure in vitro. In the present work, we present evidence that Hfq unambiguously forms amyloid structures also in vivo. Taking into account the role of this protein in bacterial adaptation and virulence, our work opens possibilities to target Hfq amyloid self-assembly and cell location, with important potential to block bacterial adaptation and treat infections.
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15
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Sharma A, Dubey V, Sharma R, Devnath K, Gupta VK, Akhter J, Bhando T, Verma A, Ambatipudi K, Sarkar M, Pathania R. The unusual glycine-rich C terminus of the Acinetobacter baumannii RNA chaperone Hfq plays an important role in bacterial physiology. J Biol Chem 2018; 293:13377-13388. [PMID: 30002121 DOI: 10.1074/jbc.ra118.002921] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/28/2018] [Indexed: 11/06/2022] Open
Abstract
Acinetobacter baumannii is a Gram-negative nosocomial pathogen that causes soft tissue infections in patients who spend a long time in intensive care units. This recalcitrant bacterium is very well known for developing rapid drug resistance, which is a combined outcome of its natural competence and mobile genetic elements. Successful efforts to treat these infections would be aided by additional information on the physiology of A. baumannii Toward that end, we recently reported on a small RNA (sRNA), AbsR25, in this bacterium that regulates the genes of several efflux pumps. Because sRNAs often require the RNA chaperone Hfq for assistance in binding to their cognate mRNA targets, we identified and characterized this protein in A. baumannii The homolog in A. baumannii is a large protein with an extended C terminus unlike Hfqs in other Gram-negative pathogens. The extension has a compositional bias toward glycine and, to a lower extent, phenylalanine and glutamine, suggestive of an intrinsically disordered region. We studied the importance of this glycine-rich tail using truncated versions of Hfq in biophysical assays and complementation of an hfq deletion mutant, finding that the tail was necessary for high-affinity RNA binding. Further tests implicate Hfq in important cellular processes of A. baumannii like metabolism, drug resistance, stress tolerance, and virulence. Our findings underline the importance of the glycine-rich C terminus in RNA binding, ribo-regulation, and auto-regulation of Hfq, demonstrating this hitherto overlooked protein motif to be an indispensable part of the A. baumannii Hfq.
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Affiliation(s)
- Atin Sharma
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Vineet Dubey
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Rajnikant Sharma
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Kuldip Devnath
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Vivek Kumar Gupta
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Jawed Akhter
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Timsy Bhando
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Aparna Verma
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Kiran Ambatipudi
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
| | - Mihir Sarkar
- the Division of Physiology and Climatology, ICAR-Indian Veterinary Research Institute, Izatnagar-Bareilly (UP) 243122, India
| | - Ranjana Pathania
- From the Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India and
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16
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Santiago-Frangos A, Woodson SA. Hfq chaperone brings speed dating to bacterial sRNA. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1475. [PMID: 29633565 PMCID: PMC6002925 DOI: 10.1002/wrna.1475] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/22/2018] [Accepted: 02/26/2018] [Indexed: 11/11/2022]
Abstract
Hfq is a ubiquitous, Sm-like RNA binding protein found in most bacteria and some archaea. Hfq binds small regulatory RNAs (sRNAs), facilitates base pairing between sRNAs and their mRNA targets, and directly binds and regulates translation of certain mRNAs. Because sRNAs regulate many stress response pathways in bacteria, Hfq is essential for adaptation to different environments and growth conditions. The chaperone activities of Hfq arise from multipronged RNA binding by three different surfaces of the Hfq hexamer. The manner in which the structured Sm core of Hfq binds RNA has been well studied, but recent work shows that the intrinsically disordered C-terminal domain of Hfq modulates sRNA binding, creating a kinetic hierarchy of RNA competition for Hfq and ensuring the release of double-stranded sRNA-mRNA complexes. A combination of structural, biophysical, and genetic experiments reveals how Hfq recognizes its RNA substrates and plays matchmaker for sRNAs and mRNAs in the cell. The interplay between structured and disordered domains of Hfq optimizes sRNA-mediated post-transcriptional regulation, and is a common theme in RNA chaperones. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry.
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Affiliation(s)
- Andrew Santiago-Frangos
- Program in Cellular, Molecular and Developmental Biology and Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Sarah A Woodson
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
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17
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Wen B, Wang W, Zhang J, Gong Q, Shi Y, Wu J, Zhang Z. Structural and dynamic properties of the C-terminal region of the Escherichia coli RNA chaperone Hfq: integrative experimental and computational studies. Phys Chem Chem Phys 2018; 19:21152-21164. [PMID: 28752165 DOI: 10.1039/c7cp01044c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In Escherichia coli, hexameric Hfq is an important RNA chaperone that facilitates small RNA-mediated post-transcriptional regulation. The Hfq monomer consists of an evolutionarily conserved Sm domain (residues 1-65) and a flexible C-terminal region (residues 66-102). It has been recognized that the existence of the C-terminal region is important for the function of Hfq, but its detailed structural and dynamic properties remain elusive due to its disordered nature. In this work, using integrative experimental techniques, such as nuclear magnetic resonance spectroscopy and small-angle X-ray scattering, as well as multi-scale computational simulations, new insights into the structure and dynamics of the C-terminal region in the context of the Hfq hexamer are provided. Although the C-terminal region is intrinsically disordered, some residues (83-86) are motionally restricted. The hexameric core may affect the secondary structure propensity of the C-terminal region, due to transient interactions between them. The residues at the rim and the proximal side of the core have significantly more transient contacts with the C-terminal region than those residues at the distal side, which may facilitate the function of the C-terminal region in the release of double-stranded RNAs and the cycling of small non-coding RNAs. Structure ensembles constructed by fitting the experimental data also support that the C-terminal region prefers to locate at the proximal side. From multi-scale simulations, we propose that the C-terminal region may play a dual role of steric effect (especially at the proximal side) and recruitment (at the both sides) in the binding process of RNA substrates. Interestingly, we have found that these motionally restricted residues may serve as important binding sites for the incoming RNAs that is probably driven by favorable electrostatic interactions. These integrative studies may aid in our understanding of the functional role of the C-terminal region of Hfq.
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Affiliation(s)
- Bin Wen
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, P. R. China.
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18
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Malabirade A, Jiang K, Kubiak K, Diaz-Mendoza A, Liu F, van Kan JA, Berret JF, Arluison V, van der Maarel JRC. Compaction and condensation of DNA mediated by the C-terminal domain of Hfq. Nucleic Acids Res 2017; 45:7299-7308. [PMID: 28521053 PMCID: PMC5499573 DOI: 10.1093/nar/gkx431] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 05/03/2017] [Indexed: 11/28/2022] Open
Abstract
Hfq is a bacterial protein that is involved in several aspects of nucleic acids metabolism. It has been described as one of the nucleoid associated proteins shaping the bacterial chromosome, although it is better known to influence translation and turnover of cellular RNAs. Here, we explore the role of Escherichia coli Hfq's C-terminal domain in the compaction of double stranded DNA. Various experimental methodologies, including fluorescence microscopy imaging of single DNA molecules confined inside nanofluidic channels, atomic force microscopy, isothermal titration microcalorimetry and electrophoretic mobility assays have been used to follow the assembly of the C-terminal and N-terminal regions of Hfq on DNA. Results highlight the role of Hfq's C-terminal arms in DNA binding, change in mechanical properties of the double helix and compaction of DNA into a condensed form. The propensity for bridging and compaction of DNA by the C-terminal domain might be related to aggregation of bound protein and may have implications for protein binding related gene regulation.
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Affiliation(s)
- Antoine Malabirade
- Laboratoire Léon Brillouin, CEA, CNRS, Université Paris Saclay, 91191 Gif-sur-Yvette, France
| | - Kai Jiang
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Krzysztof Kubiak
- Laboratoire Léon Brillouin, CEA, CNRS, Université Paris Saclay, 91191 Gif-sur-Yvette, France.,Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | | | - Fan Liu
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Jeroen A van Kan
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | | | - Véronique Arluison
- Laboratoire Léon Brillouin, CEA, CNRS, Université Paris Saclay, 91191 Gif-sur-Yvette, France.,Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
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19
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Malabirade A, Morgado-Brajones J, Trépout S, Wien F, Marquez I, Seguin J, Marco S, Velez M, Arluison V. Membrane association of the bacterial riboregulator Hfq and functional perspectives. Sci Rep 2017; 7:10724. [PMID: 28878270 PMCID: PMC5587644 DOI: 10.1038/s41598-017-11157-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/17/2017] [Indexed: 12/31/2022] Open
Abstract
Hfq is a bacterial RNA binding protein that carries out several roles in genetic expression regulation, mainly at the post-transcriptional level. Previous studies have shown its importance in growth and virulence of bacteria. Here, we provide the direct observation of its ability to interact with membranes. This was established by co-sedimentation assay, cryo-transmission electron (cryo-TEM) and atomic force (AFM) microscopies. Furthermore, our results suggest a role for its C-terminus amyloidogenic domain in membrane disruption. Precisely, AFM images of lipid bilayers in contact with Hfq C-terminus fibrils show the emergence of holes with a size dependent on the time of interaction. Cryo-TEM observations also show that liposomes are in contact with clusters of fibrils, with occasional deformation of the vesicles and afterward the apparition of a multitude of tiny vesicles in the proximity of the fibrils, suggesting peptide-induced breakage of the liposomes. Finally, circular dichroism spectroscopy demonstrated a change in the secondary structure of Hfq C-terminus upon interaction with liposomes. Altogether, these results show an unexpected property of Hfq and suggest a possible new role for the protein, exporting sRNA outside of the bacterial cell.
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Affiliation(s)
- Antoine Malabirade
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191, Gif-sur-Yvette, France
| | - Javier Morgado-Brajones
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191, Gif-sur-Yvette, France.,Instituto de Catálisis y Petroleoquímica, CSIC, c/Marie Curie, 2, Cantoblanco, E-28049, Madrid, Spain
| | - Sylvain Trépout
- Institut Curie, Research Center, PSL Research University, Chemistry, Modelisation and Imaging for Biology (CMIB) Bât 110-112, Centre Universitaire, 91405, Orsay, France.,INSERM U 1196, CNRS UMR 9187, Université Paris Saclay, Université Paris-Sud, Bât 110-112, Centre Universitaire, Rue Henri Becquerel, 91405, Orsay, France
| | - Frank Wien
- DISCO Beamline, Synchrotron SOLEIL, 91192, Gif-sur-Yvette, France
| | - Ileana Marquez
- Instituto de Catálisis y Petroleoquímica, CSIC, c/Marie Curie, 2, Cantoblanco, E-28049, Madrid, Spain
| | - Jérôme Seguin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, Cedex, France
| | - Sergio Marco
- Institut Curie, Research Center, PSL Research University, Chemistry, Modelisation and Imaging for Biology (CMIB) Bât 110-112, Centre Universitaire, 91405, Orsay, France.,INSERM U 1196, CNRS UMR 9187, Université Paris Saclay, Université Paris-Sud, Bât 110-112, Centre Universitaire, Rue Henri Becquerel, 91405, Orsay, France
| | - Marisela Velez
- Instituto de Catálisis y Petroleoquímica, CSIC, c/Marie Curie, 2, Cantoblanco, E-28049, Madrid, Spain
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191, Gif-sur-Yvette, France. .,Université Paris Diderot, 75013, Paris, France.
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20
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Santiago-Frangos A, Jeliazkov JR, Gray JJ, Woodson SA. Acidic C-terminal domains autoregulate the RNA chaperone Hfq. eLife 2017; 6:27049. [PMID: 28826489 PMCID: PMC5606850 DOI: 10.7554/elife.27049] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 08/03/2017] [Indexed: 11/15/2022] Open
Abstract
The RNA chaperone Hfq is an Sm protein that facilitates base pairing between bacterial small RNAs (sRNAs) and mRNAs involved in stress response and pathogenesis. Hfq possesses an intrinsically disordered C-terminal domain (CTD) that may tune the function of the Sm domain in different organisms. In Escherichia coli, the Hfq CTD increases kinetic competition between sRNAs and recycles Hfq from the sRNA-mRNA duplex. Here, de novo Rosetta modeling and competitive binding experiments show that the acidic tip of the E. coli Hfq CTD transiently binds the basic Sm core residues necessary for RNA annealing. The CTD tip competes against non-specific RNA binding, facilitates dsRNA release, and prevents indiscriminate DNA aggregation, suggesting that this acidic peptide mimics nucleic acid to auto-regulate RNA binding to the Sm ring. The mechanism of CTD auto-inhibition predicts the chaperone function of Hfq in bacterial genera and illuminates how Sm proteins may evolve new functions.
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Affiliation(s)
- Andrew Santiago-Frangos
- Cell, Molecular and Developmental Biology and Biophysics Program, Johns Hopkins University, Baltimore, United States
| | - Jeliazko R Jeliazkov
- Program in Molecular Biophysics, Johns Hopkins University, Baltimore, United States
| | - Jeffrey J Gray
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, United States
| | - Sarah A Woodson
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, United States
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21
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Cech GM, Szalewska-Pałasz A, Kubiak K, Malabirade A, Grange W, Arluison V, Węgrzyn G. The Escherichia Coli Hfq Protein: An Unattended DNA-Transactions Regulator. Front Mol Biosci 2016; 3:36. [PMID: 27517037 PMCID: PMC4963395 DOI: 10.3389/fmolb.2016.00036] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/13/2016] [Indexed: 11/17/2022] Open
Abstract
The Hfq protein was discovered in Escherichia coli as a host factor for bacteriophage Qβ RNA replication. Subsequent studies indicated that Hfq is a pleiotropic regulator of bacterial gene expression. The regulatory role of Hfq is ascribed mainly to its function as an RNA-chaperone, facilitating interactions between bacterial non-coding RNA and its mRNA target. Thus, it modulates mRNA translation and stability. Nevertheless, Hfq is able to interact with DNA as well. Its role in the regulation of DNA-related processes has been demonstrated. In this mini-review, it is discussed how Hfq interacts with DNA and what is the role of this protein in regulation of DNA transactions. Particularly, Hfq has been demonstrated to be involved in the control of ColE1 plasmid DNA replication, transposition, and possibly also transcription. Possible mechanisms of these Hfq-mediated regulations are described and discussed.
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Affiliation(s)
- Grzegorz M Cech
- Department of Molecular Biology, University of Gdańsk Gdańsk, Poland
| | | | - Krzysztof Kubiak
- Department of Molecular Biology, University of GdańskGdańsk, Poland; Laboratoire Léon Brillouin, CEA, Centre National de la Recherche Scientifique, Université Paris Saclay, CEA SaclayGif-sur-Yvette, France; IPCMS/Centre National de la Recherche ScientifiqueStrasbourg, France
| | - Antoine Malabirade
- Laboratoire Léon Brillouin, CEA, Centre National de la Recherche Scientifique, Université Paris Saclay, CEA Saclay Gif-sur-Yvette, France
| | - Wilfried Grange
- IPCMS/Centre National de la Recherche ScientifiqueStrasbourg, France; Universite Paris Diderot, UFR Science du VivantParis, France
| | - Veronique Arluison
- Laboratoire Léon Brillouin, CEA, Centre National de la Recherche Scientifique, Université Paris Saclay, CEA SaclayGif-sur-Yvette, France; Universite Paris Diderot, UFR Science du VivantParis, France
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, University of Gdańsk Gdańsk, Poland
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22
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Abstract
Accumulating evidence indicates that RNA metabolism components assemble into supramolecular cellular structures to mediate functional compartmentalization within the cytoplasmic membrane of the bacterial cell. This cellular compartmentalization could play important roles in the processes of RNA degradation and maturation. These components include Hfq, the RNA chaperone protein, which is involved in the post-transcriptional control of protein synthesis mainly by the virtue of its interactions with several small regulatory ncRNAs (sRNA). The Escherichia coli Hfq is structurally organized into two domains. An N-terminal domain that folds as strongly bent β-sheets within individual protomers to assemble into a typical toroidal hexameric ring. A C-terminal flexible domain that encompasses approximately one-third of the protein seems intrinsically unstructured. RNA-binding function of Hfq mainly lies within its N-terminal core, whereas the function of the flexible domain remains controversial and largely unknown. In the present study, we demonstrate that the Hfq-C-terminal region (CTR) has an intrinsic property to self-assemble into long amyloid-like fibrillar structures in vitro. We show that normal localization of Hfq within membrane-associated coiled structures in vivo requires this C-terminal domain. This finding establishes for the first time a function for the hitherto puzzling CTR, with a plausible central role in RNA transactions. We showed that Hfq C-terminal region (CTR) has an intrinsic property to self-assemble into amyloid-like fibrils. This region is required for cellular assembly of Hfq into membrane-associated coiled structures. The work establishes a new function for this naturally unstructured Hfq domain.
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23
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Jiang K, Zhang C, Guttula D, Liu F, van Kan JA, Lavelle C, Kubiak K, Malabirade A, Lapp A, Arluison V, van der Maarel JRC. Effects of Hfq on the conformation and compaction of DNA. Nucleic Acids Res 2015; 43:4332-41. [PMID: 25824948 PMCID: PMC4417175 DOI: 10.1093/nar/gkv268] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 03/18/2015] [Indexed: 12/14/2022] Open
Abstract
Hfq is a bacterial pleiotropic regulator that mediates several aspects of nucleic acids metabolism. The protein notably influences translation and turnover of cellular RNAs. Although most previous contributions concentrated on Hfq's interaction with RNA, its association to DNA has also been observed in vitro and in vivo. Here, we focus on DNA-compacting properties of Hfq. Various experimental technologies, including fluorescence microscopy imaging of single DNA molecules confined inside nanofluidic channels, atomic force microscopy and small angle neutron scattering have been used to follow the assembly of Hfq on DNA. Our results show that Hfq forms a nucleoprotein complex, changes the mechanical properties of the double helix and compacts DNA into a condensed form. We propose a compaction mechanism based on protein-mediated bridging of DNA segments. The propensity for bridging is presumably related to multi-arm functionality of the Hfq hexamer, resulting from binding of the C-terminal domains to the duplex. Results are discussed in regard to previous results obtained for H-NS, with important implications for protein binding related gene regulation.
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Affiliation(s)
- Kai Jiang
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Ce Zhang
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Durgarao Guttula
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Fan Liu
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Jeroen A van Kan
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Christophe Lavelle
- Genomes Structure and Instability, Sorbonne Universities, National Museum of Natural History, Inserm U 1154, CNRS UMR 7196, 75005 Paris, France
| | - Krzysztof Kubiak
- Laboratoire Léon Brillouin, UMR 12 CEA/CNRS, CEA-Saclay, Gif sur Yvette Cedex 91191, France Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Antoine Malabirade
- Laboratoire Léon Brillouin, UMR 12 CEA/CNRS, CEA-Saclay, Gif sur Yvette Cedex 91191, France
| | - Alain Lapp
- Laboratoire Léon Brillouin, UMR 12 CEA/CNRS, CEA-Saclay, Gif sur Yvette Cedex 91191, France
| | - Véronique Arluison
- Laboratoire Léon Brillouin, UMR 12 CEA/CNRS, CEA-Saclay, Gif sur Yvette Cedex 91191, France Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
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Hfq plays important roles in virulence and stress adaptation in Cronobacter sakazakii ATCC 29544. Infect Immun 2015; 83:2089-98. [PMID: 25754196 DOI: 10.1128/iai.03161-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 02/26/2015] [Indexed: 11/20/2022] Open
Abstract
Cronobacter spp. are opportunistic pathogens that cause neonatal meningitis and sepsis with high mortality in neonates. Despite the peril associated with Cronobacter infection, the mechanisms of pathogenesis are still being unraveled. Hfq, which is known as an RNA chaperone, participates in the interaction with bacterial small RNAs (sRNAs) to regulate posttranscriptionally the expression of various genes. Recent studies have demonstrated that Hfq contributes to the pathogenesis of numerous species of bacteria, and its roles are varied between bacterial species. Here, we tried to elucidate the role of Hfq in C. sakazakii virulence. In the absence of hfq, C. sakazakii was highly attenuated in dissemination in vivo, showed defects in invasion (3-fold) into animal cells and survival (10(3)-fold) within host cells, and exhibited low resistance to hydrogen peroxide (10(2)-fold). Remarkably, the loss of hfq led to hypermotility on soft agar, which is contrary to what has been observed in other pathogenic bacteria. The hyperflagellated bacteria were likely to be attributable to the increased transcription of genes associated with flagellar biosynthesis in a strain lacking hfq. Together, these data strongly suggest that hfq plays important roles in the virulence of C. sakazakii by participating in the regulation of multiple genes.
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25
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Wang L, Wang W, Li F, Zhang J, Wu J, Gong Q, Shi Y. Structural insights into the recognition of the internal A-rich linker from OxyS sRNA by Escherichia coli Hfq. Nucleic Acids Res 2015; 43:2400-11. [PMID: 25670676 PMCID: PMC4344510 DOI: 10.1093/nar/gkv072] [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] [Indexed: 11/22/2022] Open
Abstract
Small RNA OxyS is induced during oxidative stress in Escherichia coli and it is an Hfq-dependent negative regulator of mRNA translation. OxyS represses the translation of fhlA and rpoS mRNA, which encode the transcriptional activator and σs subunit of RNA polymerase, respectively. However, little is known regarding how Hfq, an RNA chaperone, interacts with OxyS at the atomic level. Here, using fluorescence polarization and tryptophan fluorescence quenching assays, we verified that the A-rich linker region of OxyS sRNA binds Hfq at its distal side. We also report two crystal structures of Hfq in complex with A-rich RNA fragments from this linker region. Both of these RNA fragments bind to the distal side of Hfq and adopt a different conformation compared with those previously reported for the (A-R-N)n tripartite recognition motif. Furthermore, using fluorescence polarization, electrophoresis mobility shift assays and in vivo translation assays, we found that an Hfq mutant, N48A, increases the binding affinity of OxyS for Hfq in vitro but is defective in the negative regulation of fhlA translation in vivo, suggesting that the normal function of OxyS depends on the details of the interaction with Hfq that may be related to the rapid recycling of Hfq in the cell.
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Affiliation(s)
- Lijun Wang
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Weiwei Wang
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Fudong Li
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Jiahai Zhang
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Jihui Wu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Qingguo Gong
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Yunyu Shi
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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26
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Caillet J, Gracia C, Fontaine F, Hajnsdorf E. Clostridium difficile Hfq can replace Escherichia coli Hfq for most of its function. RNA (NEW YORK, N.Y.) 2014; 20:1567-1578. [PMID: 25147238 PMCID: PMC4174439 DOI: 10.1261/rna.043372.113] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 05/31/2014] [Indexed: 06/03/2023]
Abstract
A gene for the Hfq protein is present in the majority of sequenced bacterial genomes. Its characteristic hexameric ring-like core structure is formed by the highly conserved N-terminal regions. In contrast, the C-terminal forms an extension, which varies in length, lacks homology, and is predicted to be unstructured. In Gram-negative bacteria, Hfq facilitates the pairing of sRNAs with their mRNA target and thus affects gene expression, either positively or negatively, and modulates sRNA degradation. In Gram-positive bacteria, its role is still poorly characterized. Numerous sRNAs have been detected in many Gram-positive bacteria, but it is not yet known whether these sRNAs act in association with Hfq. Compared with all other Hfqs, the C. difficile Hfq exhibits an unusual C-terminal sequence with 75% asparagine and glutamine residues, while the N-terminal core part is more conserved. To gain insight into the functionality of the C. difficile Hfq (Cd-Hfq) protein in processes regulated by sRNAs, we have tested the ability of Cd-Hfq to fulfill the functions of the E. coli Hfq (Ec-Hfq) by examining various functions associated with Hfq in both positive and negative controls of gene expression. We found that Cd-Hfq substitutes for most but not all of the tested functions of the Ec-Hfq protein. We also investigated the role of the C-terminal part of the Hfq proteins. We found that the C-terminal part of both Ec-Hfq and Cd-Hfq is not essential but contributes to some functions of both the E. coli and C. difficile chaperons.
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Affiliation(s)
- Joel Caillet
- CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Céline Gracia
- CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Fanette Fontaine
- CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Eliane Hajnsdorf
- CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
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27
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Hfq protein deficiency in Escherichia coli affects ColE1-like but not λ plasmid DNA replication. Plasmid 2014; 73:10-5. [PMID: 24811974 DOI: 10.1016/j.plasmid.2014.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/21/2014] [Accepted: 04/23/2014] [Indexed: 12/19/2022]
Abstract
Hfq is a nucleic acid-binding protein involved in controlling several aspects of RNA metabolism. It achieves this regulatory function by modulating the translational activity and stability of different mRNAs, generally via interactions with stress-related small regulatory sRNAs. However, besides its role in the coordination of translation of bacterial mRNA, Hfq is also a nucleoid-associated DNA-binding protein. Motivated by the above property of Hfq, we investigated if hfq gene mutation has implications for the regulation of DNA replication. Efficiency of ColE1-like (pMB1- and p15A replicons) and bacteriophage λ-derived plasmids' replication has been investigated in wild-type strain and otherwise isogenic hfq mutant of Escherichia coli. Significant differences in plasmid amount and kinetics of plasmid DNA synthesis were observed between the two tested bacterial hosts for ColE1-like replicons, but not for λ plasmid. Furthermore, ColE1-like plasmids replicated more efficiently in wild-type cells than in the hfq mutant in the early exponential phase of growth, but less efficiently in late exponential and early stationary phases. Hfq levels in the wild-type host, estimated by Western-blotting, were increased at the latter phases relative to the former one. Moreover, effects of the hfq mutation on ColE1-like plasmid replication were impaired in the absence of the rom gene, coding for a protein enhancing RNA I-RNA II interactions during the control of the replication initiation. These results are discussed in the light of a potential mechanism by which Hfq protein may influence replication of some, but not all, replicons in E. coli.
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28
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Robinson KE, Orans J, Kovach AR, Link TM, Brennan RG. Mapping Hfq-RNA interaction surfaces using tryptophan fluorescence quenching. Nucleic Acids Res 2013; 42:2736-49. [PMID: 24288369 PMCID: PMC3936774 DOI: 10.1093/nar/gkt1171] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Hfq is a posttranscriptional riboregulator and RNA chaperone that binds small RNAs and target mRNAs to effect their annealing and message-specific regulation in response to environmental stressors. Structures of Hfq-RNA complexes indicate that U-rich sequences prefer the proximal face and A-rich sequences the distal face; however, the Hfq-binding sites of most RNAs are unknown. Here, we present an Hfq-RNA mapping approach that uses single tryptophan-substituted Hfq proteins, all of which retain the wild-type Hfq structure, and tryptophan fluorescence quenching (TFQ) by proximal RNA binding. TFQ properly identified the respective distal and proximal binding of A15 and U6 RNA to Gram-negative Escherichia coli (Ec) Hfq and the distal face binding of (AA)3A, (AU)3A and (AC)3A to Gram-positive Staphylococcus aureus (Sa) Hfq. The inability of (GU)3G to bind the distal face of Sa Hfq reveals the (R-L)n binding motif is a more restrictive (A-L)n binding motif. Remarkably Hfq from Gram-positive Listeria monocytogenes (Lm) binds (GU)3G on its proximal face. TFQ experiments also revealed the Ec Hfq (A-R-N)n distal face-binding motif should be redefined as an (A-A-N)n binding motif. TFQ data also demonstrated that the 5'-untranslated region of hfq mRNA binds both the proximal and distal faces of Ec Hfq and the unstructured C-terminus.
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Affiliation(s)
- Kirsten E Robinson
- Department of Biochemistry, Duke University, Durham, NC 27710, USA and Department of Biochemistry and Molecular Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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29
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Wang W, Wang L, Wu J, Gong Q, Shi Y. Hfq-bridged ternary complex is important for translation activation of rpoS by DsrA. Nucleic Acids Res 2013; 41:5938-48. [PMID: 23605038 PMCID: PMC3675490 DOI: 10.1093/nar/gkt276] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The rpoS mRNA, which encodes the master regulator σ(S) of general stress response, requires Hfq-facilitated base pairing with DsrA small RNA for efficient translation at low temperatures. It has recently been proposed that one mechanism underlying Hfq action is to bridge a transient ternary complex by simultaneously binding to rpoS and DsrA. However, no structural evidence of Hfq simultaneously bound to different RNAs has been reported. We detected simultaneous binding of Hfq to rpoS and DsrA fragments. Crystal structures of AU6A•Hfq•A7 and Hfq•A7 complexes were resolved using 1.8- and 1.9-Å resolution, respectively. Ternary complex has been further verified in solution by NMR. In vivo, activation of rpoS translation requires intact Hfq, which is capable of bridging rpoS and DsrA simultaneously into ternary complex. This ternary complex possibly corresponds to a meta-stable transition state in Hfq-facilitated small RNA-mRNA annealing process.
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Affiliation(s)
- Weiwei Wang
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, P R China
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30
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Abstract
Over the past years, small non-coding RNAs (sRNAs) emerged as important modulators of gene expression in bacteria. Guided by partial sequence complementarity, these sRNAs interact with target mRNAs and eventually affect transcript stability and translation. The physiological function of sRNAs depends on the protein Hfq, which binds sRNAs in the cell and promotes the interaction with their mRNA targets. This important physiological function of Hfq as a central hub of sRNA-mediated regulation made it one of the most intensely studied proteins in bacteria. Recently, a new model for sRNA binding by Hfq has been proposed that involves the direct recognition of the sRNA 3' end and interactions of the sRNA body with the lateral RNA-binding surface of Hfq. This review summarizes the current understanding of the RNA binding properties of Hfq and its (s)RNA complexes. Moreover, the implications of the new binding model for sRNA-mediated regulation are discussed.
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Affiliation(s)
- Evelyn Sauer
- Biozentrum, University of Basel, Basel, Switzerland.
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31
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Multiple activities of RNA-binding proteins S1 and Hfq. Biochimie 2012; 94:1544-53. [DOI: 10.1016/j.biochi.2012.02.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/10/2012] [Indexed: 01/16/2023]
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32
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Murina VN, Nikulin AD. RNA-binding Sm-like proteins of bacteria and archaea. similarity and difference in structure and function. BIOCHEMISTRY (MOSCOW) 2012; 76:1434-49. [PMID: 22339597 DOI: 10.1134/s0006297911130050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
RNA-binding proteins play a significant role in many processes of RNA metabolism, such as splicing and processing, regulation of DNA transcription and RNA translation, etc. Among the great number of RNA-binding proteins, so-called RNA-chaperones occupy an individual niche; they were named for their ability to assist RNA molecules to gain their accurate native spatial structure. When binding with RNAs, they possess the capability of altering (melting) their secondary structure, thus providing a possibility for formation of necessary intramolecular contacts between individual RNA sites for proper folding. These proteins also have an additional helper function in RNA-RNA and RNA-protein interactions. Members of such class of the RNA-binding protein family are Sm and Sm-like proteins (Sm-Like, LSm). The presence of these proteins in bacteria, archaea, and eukaryotes emphasizes their biological significance. These proteins are now attractive for researchers because of their implication in many processes associated with RNAs in bacterial and archaeal cells. This review is focused on a comparison of architecture of bacterial and archaeal LSm proteins and their interaction with different RNA molecules.
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Affiliation(s)
- V N Murina
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
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33
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Vincent HA, Henderson CA, Ragan TJ, Garza-Garcia A, Cary PD, Gowers DM, Malfois M, Driscoll PC, Sobott F, Callaghan AJ. Characterization of Vibrio cholerae Hfq provides novel insights into the role of the Hfq C-terminal region. J Mol Biol 2012; 420:56-69. [PMID: 22484176 PMCID: PMC3477312 DOI: 10.1016/j.jmb.2012.03.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 03/02/2012] [Accepted: 03/29/2012] [Indexed: 11/05/2022]
Abstract
Hfq is a bacterial RNA binding protein that facilitates small RNA-mediated posttranscriptional gene regulation. In Vibrio cholerae, Hfq and four Hfq-dependent small RNAs are essential for the expression of virulence genes, but little is known about this mechanism at the molecular level. To better understand V. cholerae Hfq structure and mechanism, we characterized the protein, alongside Escherichia coli Hfq for comparison, using biochemical and biophysical techniques. The N-terminal domain (NTD) of the two proteins is highly conserved, but the C-terminal regions (CTRs) vary in both sequence and length. Small-angle X-ray scattering studies showed that both proteins adopt a star-shaped hexameric structure in which the conserved NTD adopts the expected Sm fold while the variable CTR is disordered and extends radially outwards from the folded core. Despite their structural similarity, SDS-PAGE stability assays and collision-induced dissociation mass spectrometry revealed that the V. cholerae hexamer is less stable than that of E. coli. We propose that this is due to minor differences between the intersubunit interface formed by the NTDs and the ability of the E. coli CTR to stabilize this interface. However, based on electrophoretic mobility shift assays, the divergent CTRs do appear to perform a common function with regard to RNA-binding specificity. Overall, the similarities and differences in the fundamental properties of V. cholerae and E. coli Hfq provide insight into their assembly and molecular mechanisms.
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Affiliation(s)
- Helen A Vincent
- Biophysics Laboratories, School of Biological Sciences, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, UK
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34
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Sobrero P, Valverde C. The bacterial protein Hfq: much more than a mere RNA-binding factor. Crit Rev Microbiol 2012; 38:276-99. [DOI: 10.3109/1040841x.2012.664540] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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35
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Panja S, Woodson SA. Hexamer to monomer equilibrium of E. coli Hfq in solution and its impact on RNA annealing. J Mol Biol 2012; 417:406-12. [PMID: 22326348 DOI: 10.1016/j.jmb.2012.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 12/12/2011] [Accepted: 02/06/2012] [Indexed: 10/14/2022]
Abstract
The bacterial Sm-like protein Hfq forms a ring-shaped homo-hexamer that is necessary for Hfq to bind nucleic acids and to act in small noncoding RNA regulation. Using semi-native gels and fluorescence anisotropy, we show that Hfq undergoes a cooperative conformational change from monomer to hexamer around 1 μM protein, which is comparable to the in vivo concentration of Hfq and above the dissociation constant of the Hfq hexamer from many RNA substrates. Above 2 μM protein, Hfq hexamers associate in high-molecular-weight complexes. Mutations that impair RNA binding to the proximal face strongly destabilize the hexamer, while the mutation R16A near the outer rim prevents hexamer association. Stopped-flow fluorescence resonance energy transfer experiments showed that Hfq subunits interact within a few seconds, suggesting that Hfq monomers, hexamers and multi-hexamer complexes are in dynamic equilibrium. Finally, we show that Hfq is most active in RNA annealing when the hexamer is present. These results suggest that RNA binding is coupled to hexamer assembly and that the biochemical activity of Hfq reflects the equilibrium between different quaternary structures.
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Affiliation(s)
- Subrata Panja
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
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36
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Beich-Frandsen M, Večerek B, Sjöblom B, Bläsi U, Djinović-Carugo K. Structural analysis of full-length Hfq from Escherichia coli. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:536-40. [PMID: 21543856 PMCID: PMC3087635 DOI: 10.1107/s174430911100786x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 03/02/2011] [Indexed: 01/06/2023]
Abstract
The structure of full-length host factor Qβ (Hfq) from Escherichia coli obtained from a crystal belonging to space group P1, with unit-cell parameters a = 61.91, b = 62.15, c = 81.26 Å, α = 78.6, β = 86.2, γ = 59.9°, was solved by molecular replacement to a resolution of 2.85 Å and refined to R(work) and R(free) values of 20.7% and 25.0%, respectively. Hfq from E. coli has previously been crystallized and the structure has been solved for the N-terminal 72 amino acids, which cover ~65% of the full-length sequence. Here, the purification, crystallization and structural data of the full 102-amino-acid protein are presented. These data revealed that the presence of the C-terminus changes the crystal packing of E. coli Hfq. The crystal structure is discussed in the context of the recently published solution structure of Hfq from E. coli.
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Affiliation(s)
- Mads Beich-Frandsen
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Branislav Večerek
- Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Björn Sjöblom
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Udo Bläsi
- Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
- Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
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37
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Beich-Frandsen M, Vecerek B, Konarev PV, Sjöblom B, Kloiber K, Hämmerle H, Rajkowitsch L, Miles AJ, Kontaxis G, Wallace BA, Svergun DI, Konrat R, Bläsi U, Djinovic-Carugo K. Structural insights into the dynamics and function of the C-terminus of the E. coli RNA chaperone Hfq. Nucleic Acids Res 2011; 39:4900-15. [PMID: 21330354 PMCID: PMC3113564 DOI: 10.1093/nar/gkq1346] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The hexameric Escherichia coli RNA chaperone Hfq (Hfq(Ec)) is involved in riboregulation of target mRNAs by small trans-encoded RNAs. Hfq proteins of different bacteria comprise an evolutionarily conserved core, whereas the C-terminus is variable in length. Although the structure of the conserved core has been elucidated for several Hfq proteins, no structural information has yet been obtained for the C-terminus. Using bioinformatics, nuclear magnetic resonance spectroscopy, synchrotron radiation circular dichroism (SRCD) spectroscopy and small angle X-ray scattering we provide for the first time insights into the conformation and dynamic properties of the C-terminal extension of Hfq(Ec). These studies indicate that the C-termini are flexible and extend laterally away from the hexameric core, displaying in this way features typical of intrinsically disordered proteins that facilitate intermolecular interactions. We identified a minimal, intrinsically disordered region of the C-terminus supporting the interactions with longer RNA fragments. This minimal region together with rest of the C-terminal extension provides a flexible moiety capable of tethering long and structurally diverse RNA molecules. Furthermore, SRCD spectroscopy supported the hypothesis that RNA fragments exceeding a certain length interact with the C-termini of Hfq(Ec).
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Affiliation(s)
- Mads Beich-Frandsen
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
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38
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Geinguenaud F, Calandrini V, Teixeira J, Mayer C, Liquier J, Lavelle C, Arluison V. Conformational transition of DNA bound to Hfq probed by infrared spectroscopy. Phys Chem Chem Phys 2011; 13:1222-9. [DOI: 10.1039/c0cp01084g] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Fender A, Elf J, Hampel K, Zimmermann B, Wagner EGH. RNAs actively cycle on the Sm-like protein Hfq. Genes Dev 2010; 24:2621-6. [PMID: 21123649 DOI: 10.1101/gad.591310] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Hfq, a protein required for small RNA (sRNA)-mediated regulation in bacteria, binds RNA with low-nanomolar K(d) values and long half-lives of complexes (>100 min). This cannot be reconciled with the 1- 2-min response time of regulation in vivo. We show that RNAs displace each other on Hfq on a short time scale by RNA concentration-driven (active) cycling. Already at submicromolar concentrations of competitor RNA, half-lives of RNA-Hfq complexes are ≈1 min. We propose that competitor RNA associates transiently with RNA-Hfq complexes, RNAs exchange binding sites, and one of the RNAs eventually dissociates. This solves the "strong binding-high turnover" paradox and permits efficient use of the Hfq pool.
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Affiliation(s)
- Aurélie Fender
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Sweden
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40
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Olsen AS, Møller-Jensen J, Brennan RG, Valentin-Hansen P. C-terminally truncated derivatives of Escherichia coli Hfq are proficient in riboregulation. J Mol Biol 2010; 404:173-82. [PMID: 20888338 DOI: 10.1016/j.jmb.2010.09.038] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 09/16/2010] [Accepted: 09/18/2010] [Indexed: 10/19/2022]
Abstract
The prokaryotic Sm-like protein Hfq plays an essential role in the stability and function of trans-encoded small regulatory RNAs in enterobacteria that function in posttranscriptional control by base-pairing with cognate target mRNAs. Hfq associates with both regulatory RNA and target RNA, and its interaction promotes annealing. So far, mutational and structural studies have established that Escherichia coli Hfq contains two separate RNA binding sites that are part of the conserved N-terminal portion of the protein. Moreover, it has been suggested that the nonconserved C-terminal extension of E. coli Hfq might constitute a third RNA interaction surface with specificity for mRNA. However, the role of the C-terminus has not been fully resolved but is clearly important for a complete understanding of Hfq function in posttranscriptional regulation and RNA decay. Here we examined the ability of E. coli Hfq derivatives, consisting of the conserved core and short C-terminal extensions, to support the regulation of rpoS expression and riboregulation by various well-characterized small regulatory RNAs. Our data show that, in all cases tested, the truncated proteins are fully capable of promoting posttranscriptional control, indicating that the C-terminal tail of E. coli Hfq plays a small role or no role in riboregulation.
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Affiliation(s)
- Anders Steno Olsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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E. coli DNA associated with isolated Hfq interacts with Hfq's distal surface and C-terminal domain. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:588-96. [PMID: 20619373 DOI: 10.1016/j.bbagrm.2010.06.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 06/15/2010] [Accepted: 06/29/2010] [Indexed: 11/20/2022]
Abstract
The RNA-binding protein Hfq has been studied extensively for its function as a modulator of gene expression at the post-transcriptional level. While most Hfq studies have focused on the protein's interaction with sRNAs and mRNAs, Hfq binding to DNA has been observed but is less explored. During the isolation of Hfq from Escherichiacoli, we found genomic DNA fragments associated with the protein after multiple steps of purification. Sequences of 41 amplified segments from the DNA fragments associated with Hfq were determined. A large fraction of the DNA segments were predicted to have significant helical axis curvature and were from genes associated with membrane proteins, characteristics unexpected for non-specific binding. Analysis by analytical ultracentrifugation indicated that rA(18) binding to Hfq disrupts Hfq-DNA interactions. The latter observation suggests Hfq binding to DNA involves its distal surface. This was supported by a gel mobility shift assay that showed single amino acid mutations on the distal surface of Hfq inhibited Hfq binding to duplex DNA, while six of seven mutations on the proximal surface and outer circumference of the hexamer did not prevent Hfq binding. Two mutated Hfq which have portions of their C-terminal domain removed also failed to bind to DNA. The apparent K(d) for binding wild type Hfq to several duplex DNA was estimated from a gel mobility shift assay to be ~400nM.
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Abstract
Hfq is a small, highly abundant hexameric protein that is found in many bacteria and plays a critical role in mRNA expression and RNA stability. As an "RNA chaperone," Hfq binds AU-rich sequences and facilitates the trans annealing of small RNAs (sRNAs) to their target mRNAs, typically resulting in the down-regulation of gene expression. Hfq also plays a key role in bacterial RNA decay by binding tightly to polyadenylate [poly(A)] tracts. The structural mechanism by which Hfq recognizes and binds poly(A) is unknown. Here, we report the crystal structure of Escherichia coli Hfq bound to the poly(A) RNA, A(15). The structure reveals a unique RNA binding mechanism. Unlike uridine-containing sequences, which bind to the "proximal" face, the poly(A) tract binds to the "distal" face of Hfq using 6 tripartite binding motifs. Each motif consists of an adenosine specificity site (A site), which is effected by peptide backbone hydrogen bonds, a purine nucleotide selectivity site (R site), and a sequence-nondiscriminating RNA entrance/exit site (E site). The resulting implication that Hfq can bind poly(A-R-N) triplets, where R is a purine nucleotide and N is any nucleotide, was confirmed by binding studies. Indeed, Hfq bound to the oligoribonucleotides (AGG)(8), (AGC)(8), and the shorter (A-R-N)(4) sequence, AACAACAAGAAG, with nanomolar affinities. The abundance of (A-R-N)(4) and (A-R-N)(5) triplet repeats in the E. coli genome suggests additional RNA targets for Hfq. Further, the structure provides insight into Hfq-mediated sRNA-mRNA annealing and the role of Hfq in RNA decay.
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43
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Bicaudal C and trailer hitch have similar roles in gurken mRNA localization and cytoskeletal organization. Dev Biol 2009; 328:434-44. [PMID: 19217894 DOI: 10.1016/j.ydbio.2009.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 01/13/2009] [Accepted: 02/03/2009] [Indexed: 01/16/2023]
Abstract
Bicaudal C and trailer hitch are both required for dorsoventral patterning of the Drosophila oocyte. Each mutant produces ventralized eggs, a phenotype typically associated with failure of the oocyte to provide a dorsalization signal--the Gurken protein--to the follicle cells. Bicaudal C and trailer hitch are both implicated in post-transcriptional gene regulation. Bicaudal C acts in recruiting a deadenylase to specific mRNAs, leading to translational repression. The role of trailer hitch is less well defined, but mutants have defects in protein secretion, and show aberrant distribution of an endoplasmic reticulum exit site marker whose mRNA is associated with Trailer hitch protein. We show that Bicaudal C and trailer hitch interact genetically. Mutants of these two genes have shared defects in localization of gurken and other anteriorly-localized mRNAs, as well as altered microtubule organization which may underlie the mRNA localization defects. Bicaudal C and trailer hitch mutants also share a syndrome of actin-related abnormalities, including the formation of ectopic actin cages near the anterior of the oocyte. The cages sequester Gurken protein, blocking its secretion and thus interfering with signaling of the follicle cells to specify dorsal fate.
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44
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Richards J, Sundermeier T, Svetlanov A, Karzai AW. Quality control of bacterial mRNA decoding and decay. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2008; 1779:574-82. [PMID: 18342642 DOI: 10.1016/j.bbagrm.2008.02.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 02/05/2008] [Indexed: 11/19/2022]
Abstract
Studies in eukaryotes and prokaryotes have revealed that gene expression is not only controlled through altering the rate of transcription but also through varying rates of translation and mRNA decay. Indeed, the expression level of a protein is strongly affected by the steady state level of its mRNA. RNA decay can, along with transcription, play an important role in regulating gene expression by fine-tuning the steady state level of a given transcript and affecting its subsequent decoding during translation. Alterations in mRNA stability can in turn have dramatic effects on cell physiology and as a consequence the fitness and survival of the organism. Recent evidence suggests that mRNA decay can be regulated in response to environmental cues in order to enable the organism to adapt to its changing surroundings. Bacteria have evolved unique post transcriptional control mechanisms to enact such adaptive responses through: 1) general mRNA decay, 2) differential mRNA degradation using small non-coding RNAs (sRNAs), and 3) selective mRNA degradation using the tmRNA quality control system. Here, we review our current understanding of these molecular mechanisms, gleaned primarily from studies of the model gram negative organism Escherichia coli, that regulate the stability and degradation of normal and defective transcripts.
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Affiliation(s)
- Jamie Richards
- Department of Biochemistry and Cell Biology, Center for Infectious Diseases of Stony Brook University, Stony Brook, NY 11794, USA
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45
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Vecerek B, Rajkowitsch L, Sonnleitner E, Schroeder R, Bläsi U. The C-terminal domain of Escherichia coli Hfq is required for regulation. Nucleic Acids Res 2007; 36:133-43. [PMID: 18000007 PMCID: PMC2248732 DOI: 10.1093/nar/gkm985] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The Escherichia coli RNA chaperone Hfq is involved in riboregulation of target mRNAs by small trans-encoded non-coding (ncRNAs). Previous structural and genetic studies revealed a RNA-binding surface on either site of the Hfq-hexamer, which suggested that one hexamer can bring together two RNAs in a pairwise fashion. The Hfq proteins of different bacteria consist of an evolutionarily conserved core, whereas there is considerable variation at the C-terminus, with the γ- and β-proteobacteria possessing the longest C-terminal extension. Using different model systems, we show that a C-terminally truncated variant of Hfq (Hfq65), comprising the conserved hexameric core of Hfq, is defective in auto- and riboregulation. Although Hfq65 retained the capacity to bind ncRNAs, and, as evidenced by fluorescence resonance energy transfer assays, to induce structural changes in the ncRNA DsrA, the truncated variant was unable to accommodate two non-complementary RNA oligonucleotides, and was defective in mRNA binding. These studies indicate that the C-terminal extension of E. coli Hfq constitutes a hitherto unrecognized RNA interaction surface with specificity for mRNAs.
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Affiliation(s)
- Branislav Vecerek
- Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, 1030 Vienna, Austria
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46
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Yuan Y, Compton SA, Sobczak K, Stenberg MG, Thornton CA, Griffith JD, Swanson MS. Muscleblind-like 1 interacts with RNA hairpins in splicing target and pathogenic RNAs. Nucleic Acids Res 2007; 35:5474-86. [PMID: 17702765 PMCID: PMC2018611 DOI: 10.1093/nar/gkm601] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The MBNL and CELF proteins act antagonistically to control the alternative splicing of specific exons during mammalian postnatal development. This process is dysregulated in myotonic dystrophy because MBNL proteins are sequestered by (CUG)n and (CCUG)n RNAs expressed from mutant DMPK and ZNF9 genes, respectively. While these observations predict that MBNL proteins have a higher affinity for these pathogenic RNAs versus their normal splicing targets, we demonstrate that MBNL1 possesses comparably high affinities for (CUG)n and (CAG)n RNAs as well as a splicing target, Tnnt3. Mapping of a MBNL1-binding site upstream of the Tnnt3 fetal exon indicates that a preferred binding site for this protein is a GC-rich RNA hairpin containing a pyrimidine mismatch. To investigate how pathogenic RNAs sequester MBNL1 in DM1 cells, we used a combination of chemical/enzymatic structure probing and electron microscopy to determine that MBNL1 forms a ring-like structure which binds to the dsCUG helix. While the MBNL1 N-terminal region is required for RNA binding, the C-terminal region mediates homotypic interactions which may stabilize intra- and/or inter-ring interactions. Our results provide a mechanistic basis for dsCUG-induced MBNL1 sequestration and highlight a striking similarity in the binding sites for MBNL proteins on splicing precursor and pathogenic RNAs.
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Affiliation(s)
- Yuan Yuan
- Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC and Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Sarah A. Compton
- Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC and Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Krzysztof Sobczak
- Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC and Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Myrna G. Stenberg
- Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC and Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Charles A. Thornton
- Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC and Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Jack D. Griffith
- Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC and Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Maurice S. Swanson
- Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC and Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
- *To whom correspondence should be addressed. +1 352 273 8076+1 352 273 8284
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47
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Ziolkowska K, Derreumaux P, Folichon M, Pellegrini O, Régnier P, Boni IV, Hajnsdorf E. Hfq variant with altered RNA binding functions. Nucleic Acids Res 2006; 34:709-20. [PMID: 16449205 PMCID: PMC1356530 DOI: 10.1093/nar/gkj464] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 12/19/2005] [Accepted: 01/07/2006] [Indexed: 11/15/2022] Open
Abstract
The interaction between Hfq and RNA is central to multiple regulatory processes. Using site-directed mutagenesis, we have found a missense mutation in Hfq (V43R) which strongly affects2 the RNA binding capacity of the Hfq protein and its ability to stimulate poly(A) tail elongation by poly(A)-polymerase in vitro. In vivo, overexpression of this Hfq variant fails to stimulate rpoS-lacZ expression and does not restore a normal growth rate in hfq null mutant. Cells in which the wild-type gene has been replaced by the hfqV43R allele exhibit a phenotype intermediate between those of the wild-type and of the hfq minus or null strains. This missense mutation derepresses Hfq synthesis. However, not all Hfq functions are affected by this mutation. For example, HfqV43R represses OppA synthesis as strongly as the wild-type protein. The dominant negative effect of the V43R mutation over the wild-type allele suggests that hexamers containing variant and genuine subunits are presumably not functional. Finally, molecular dynamics studies indicate that the V43R substitution mainly changes the position of the K56 and Y55 side chains involved in the Hfq-RNA interaction but has probably no effect on the folding and the oligomerization of the protein.
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Affiliation(s)
- Katarzyna Ziolkowska
- ‘Régulation de l'Expression Génétique chez les Microorganismes’ UPR CNRS no. 9073conventionnée avec l'Université Paris 7, Denis Diderot, Paris, France
- ‘Laboratoire de Biochimie Théorique’ UPR CNRS no. 9080 conventionnée avec l'Université Paris 7Denis Diderot, Paris, France
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences117997 Moscow, Russia
| | - Philippe Derreumaux
- ‘Laboratoire de Biochimie Théorique’ UPR CNRS no. 9080 conventionnée avec l'Université Paris 7Denis Diderot, Paris, France
| | - Marc Folichon
- ‘Régulation de l'Expression Génétique chez les Microorganismes’ UPR CNRS no. 9073conventionnée avec l'Université Paris 7, Denis Diderot, Paris, France
- ‘Laboratoire de Biochimie Théorique’ UPR CNRS no. 9080 conventionnée avec l'Université Paris 7Denis Diderot, Paris, France
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences117997 Moscow, Russia
| | - Olivier Pellegrini
- ‘Régulation de l'Expression Génétique chez les Microorganismes’ UPR CNRS no. 9073conventionnée avec l'Université Paris 7, Denis Diderot, Paris, France
- ‘Laboratoire de Biochimie Théorique’ UPR CNRS no. 9080 conventionnée avec l'Université Paris 7Denis Diderot, Paris, France
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences117997 Moscow, Russia
| | - Philippe Régnier
- ‘Régulation de l'Expression Génétique chez les Microorganismes’ UPR CNRS no. 9073conventionnée avec l'Université Paris 7, Denis Diderot, Paris, France
- ‘Laboratoire de Biochimie Théorique’ UPR CNRS no. 9080 conventionnée avec l'Université Paris 7Denis Diderot, Paris, France
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences117997 Moscow, Russia
| | - Irina V. Boni
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences117997 Moscow, Russia
| | - Eliane Hajnsdorf
- To whom correspondence should be addressed at UPR CNRS 9073, conventionnée avec l'Université Paris 7, Denis Diderot, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France. Tel: +33 1 58 41 51 26; Fax: +33 1 58 41 50 20;
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48
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Arluison V, Mura C, Guzmán MR, Liquier J, Pellegrini O, Gingery M, Régnier P, Marco S. Three-dimensional structures of fibrillar Sm proteins: Hfq and other Sm-like proteins. J Mol Biol 2005; 356:86-96. [PMID: 16337963 DOI: 10.1016/j.jmb.2005.11.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Revised: 11/02/2005] [Accepted: 11/03/2005] [Indexed: 10/25/2022]
Abstract
Hfq is a nucleic acid-binding protein that functions as a global regulator of gene expression by virtue of its interactions with several small, non-coding RNA species. Originally identified as an Escherichia coli host factor required for RNA phage Qbeta replication, Hfq is now known to post-transcriptionally regulate bacterial gene expression by modulating both mRNA stability and translational activity. Recently shown to be a member of the diverse Sm protein family, Hfq adopts the OB-like fold typical of other Sm and Sm-like (Lsm) proteins, and also assembles into toroidal homo-oligomers that bind single-stranded RNA. Similarities between the structures, functions, and evolution of Sm/Lsm proteins and Hfq are continually being discovered, and we now report an additional, unexpected biophysical property that is shared by Hfq and other Sm proteins: E.coli Hfq polymerizes into well-ordered fibres whose morphologies closely resemble those found for Sm-like archaeal proteins (SmAPs). However, the hierarchical assembly of these fibres is dissimilar: whereas SmAPs polymerize into polar tubes (and striated bundles of such tubes) by head-to-tail stacking of individual homo-heptamers, helical Hfq fibres are formed by cylindrical slab-like layers that consist of 36 subunits arranged as a hexamer of Hfq homo-hexamers (i.e. protofilaments in a 6 x 6 arrangement). The different fibrillar ultrastructures formed by Hfq and SmAP are presented and examined herein, with the overall goal of elucidating another similarity amongst the diverse members of the Sm protein family.
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Affiliation(s)
- Véronique Arluison
- Institut de Biologie Physico-Chimique, CNRS UPR 9073 conventionnée avec l'université Paris 7, 13 rue P. et M. Curie, 75005 Paris, France.
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49
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Sonnleitner E, Napetschnig J, Afonyushkin T, Ecker K, Vecerek B, Moll I, Kaberdin VR, Bläsi U. Functional effects of variants of the RNA chaperone Hfq. Biochem Biophys Res Commun 2004; 323:1017-23. [PMID: 15381101 DOI: 10.1016/j.bbrc.2004.08.190] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2004] [Indexed: 11/17/2022]
Abstract
The ring-shaped RNA chaperone Hfq has recently received much attention owing to its multiple roles in RNA metabolism. In this study we have performed a mutational analysis of the Escherichia coli hfq gene, and have studied the effects of amino acid substitutions at several positions in the Hfq protein as well as of C-terminal truncations on its role in phage Qbeta replication, in repression of a target mRNA, and on the stability of the small regulatory RNA DsrA. These functional studies provided insights into the interaction of Hfq with RNA and suggested a role for the C-terminus of Hfq in DsrA stability.
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Affiliation(s)
- Elisabeth Sonnleitner
- Max F. Perutz Laboratories, Department of Microbiology and Genetics, University Departments at the Vienna Biocenter, Dr. Bohrgasse 9/4, 1030 Vienna, Austria
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50
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Mikulecky PJ, Kaw MK, Brescia CC, Takach JC, Sledjeski DD, Feig AL. Escherichia coli Hfq has distinct interaction surfaces for DsrA, rpoS and poly(A) RNAs. Nat Struct Mol Biol 2004; 11:1206-14. [PMID: 15531892 PMCID: PMC3071270 DOI: 10.1038/nsmb858] [Citation(s) in RCA: 212] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Accepted: 09/30/2004] [Indexed: 11/08/2022]
Abstract
The bacterial Sm-like protein Hfq facilitates RNA-RNA interactions involved in post-transcriptional regulation of the stress response. Specifically, Hfq helps pair noncoding RNAs (ncRNAs) with complementary regions of target mRNAs. To probe the mechanism of this pairing, we generated a series of Hfq mutants and measured their affinity for RNAs like those with which Hfq must associate in vivo. We tested the mutants' DsrA-dependent activation of rpoS, and their ability to stabilize DsrA ncRNA against degradation in vivo. Our results suggest that Hfq has two independent RNA-binding surfaces. In addition to a well-known site around the core of the Hfq hexamer, we observe interactions with the distal face of Hfq, a new locus with which mRNAs and poly(A) sequences associate. Our model explains how Hfq can simultaneously bind a ncRNA and its mRNA target to facilitate the strand displacement reaction required for Hfq-dependent translational regulation.
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Affiliation(s)
- Peter J Mikulecky
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405, USA
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