1
|
Gruffaz C, Smirnov A. GTPase Era at the heart of ribosome assembly. Front Mol Biosci 2023; 10:1263433. [PMID: 37860580 PMCID: PMC10582724 DOI: 10.3389/fmolb.2023.1263433] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/21/2023] [Indexed: 10/21/2023] Open
Abstract
Ribosome biogenesis is a key process in all organisms. It relies on coordinated work of multiple proteins and RNAs, including an array of assembly factors. Among them, the GTPase Era stands out as an especially deeply conserved protein, critically required for the assembly of bacterial-type ribosomes from Escherichia coli to humans. In this review, we bring together and critically analyze a wealth of phylogenetic, biochemical, structural, genetic and physiological data about this extensively studied but still insufficiently understood factor. We do so using a comparative and, wherever possible, synthetic approach, by confronting observations from diverse groups of bacteria and eukaryotic organelles (mitochondria and chloroplasts). The emerging consensus posits that Era intervenes relatively early in the small subunit biogenesis and is essential for the proper shaping of the platform which, in its turn, is a prerequisite for efficient translation. The timing of Era action on the ribosome is defined by its interactions with guanosine nucleotides [GTP, GDP, (p)ppGpp], ribosomal RNA, and likely other factors that trigger or delay its GTPase activity. As a critical nexus of the small subunit biogenesis, Era is subject to sophisticated regulatory mechanisms at the transcriptional, post-transcriptional, and post-translational levels. Failure of these mechanisms or a deficiency in Era function entail dramatic generalized consequences for the protein synthesis and far-reaching, pleiotropic effects on the organism physiology, such as the Perrault syndrome in humans.
Collapse
Affiliation(s)
- Christelle Gruffaz
- UMR7156- Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, Centre National de la Recherche Scientifique (CNRS), Strasbourg, France
| | - Alexandre Smirnov
- UMR7156- Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, Centre National de la Recherche Scientifique (CNRS), Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| |
Collapse
|
2
|
Das S, Chatterjee A, Datta PP. Knockdown Experiment Reveals an Essential GTPase CgtA's Involvement in Growth, Viability, Motility, Morphology, and Persister Phenotypes in Vibrio cholerae. Microbiol Spectr 2023; 11:e0318122. [PMID: 36916969 PMCID: PMC10100748 DOI: 10.1128/spectrum.03181-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/13/2023] [Indexed: 03/16/2023] Open
Abstract
CgtA is an essential bacterial GTPase consisting of a highly conserved N-terminal Spo0B-associated GTP-binding protein (Obg) domain, a central GTPase domain, and a variable C-terminal domain (CTD). This study reports global changes in the proteome and transcriptome of wild-type (Wt) versus full-length CgtA-depleted Vibrio cholerae in minimal media. Comparative transcriptome sequencing (RNA-Seq), followed by comparative proteomic analyses, revealed that the knockdown of cgtA significantly altered expressions of 311 proteins involved in diverse cellular activities, many of which are associated with the survival of V. cholerae. Various intracellular functional roles of CgtA in growth, viability, motility, morphology, and persister phenotypes in V. cholerae are revealed based on subsequent confirmatory experiments. Furthermore, a more sustained mRNA expression pattern of cgtA in a minimal medium than in a rich medium was also observed for Wt V. cholerae, where the highest level of mRNA expression of cgtA was observed during the logarithmic growth phase. Thereby, we propose that minimal medium-associated reduced growth rate coupled with cgtA depletion aggravates the intracellular stress in V. cholerae, interrupting vital cellular processes. The functional role of the CTD in V. cholerae is not fully understood. Hence, to specifically investigate the intracellular role of the 57-amino-acid-long CTD of CgtAVC, the CTD-only portion of CgtA was deleted. Subsequent proteomics studies revealed an altered expression of 240 proteins in the CgtA(ΔCTD) mutant, having major overlap with the full-length cgtA-deleted condition. Overall, our study reveals an alternative facet of the survival mechanism of V. cholerae during nutritional downshift as per the concomitant consequences of cgtA depletion. IMPORTANCE It is very important that we must find new drug target proteins from multidrug-resistant human-pathogenic organisms like V. cholerae. CgtA is among such potential candidates, and here, we are reporting about some newly identified cellular roles of it that are important for the survival of V. cholerae. Briefly, we knocked down the full-length cgtA gene, as well as did a partial deletion of this gene from the V. cholerae genome followed by RNA-Seq and proteomics studies. Results from our study revealed up- and downregulation of several known and unknown genes and proteins as the effect of the cgtA knockdown experiment. Also, we have presented some interesting observations that are linked with cgtA for growth, viability, motility, morphology, and persister phenotypes in V. cholerae. Our study enhances the importance of CgtA and paves the way for further exploration based on our provided data.
Collapse
Affiliation(s)
- Sagarika Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, West Bengal, India
| | - Ananya Chatterjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, West Bengal, India
| | - Partha Pratim Datta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, West Bengal, India
| |
Collapse
|
3
|
Abstract
Since Jacques Monod's foundational work in the 1940s, investigators studying bacterial physiology have largely (but not exclusively) focused on the exponential phase of bacterial cultures, which is characterized by rapid growth and high biosynthesis activity in the presence of excess nutrients. However, this is not the predominant state of bacterial life. In nature, most bacteria experience nutrient limitation most of the time. In fact, investigators even prior to Monod had identified other aspects of bacterial growth, including what is now known as the stationary phase, when nutrients become limiting. This review will discuss how bacteria transition to growth arrest in response to nutrient limitation through changes in transcription, translation, and metabolism. We will then examine how these changes facilitate survival during potentially extended periods of nutrient limitation, with particular attention to the metabolic strategies that underpin bacterial longevity in this state.
Collapse
Affiliation(s)
- Jonathan Dworkin
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY, USA;
| | - Caroline S Harwood
- Department of Microbiology, University of Washington, Seattle, Washington, USA;
| |
Collapse
|
4
|
Naganathan A, Culver GM. Interdependency and Redundancy Add Complexity and Resilience to Biogenesis of Bacterial Ribosomes. Annu Rev Microbiol 2022; 76:193-210. [PMID: 35609945 DOI: 10.1146/annurev-micro-041020-121806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pace and efficiency of ribosomal subunit production directly impact the fitness of bacteria. Biogenesis demands more than just the union of ribosomal components, including RNA and proteins, to form this functional ribonucleoprotein particle. Extra-ribosomal protein factors play a fundamental role in the efficiency and efficacy of ribosomal subunit biogenesis. A paucity of data on intermediate steps, multiple and overlapping pathways, and the puzzling number of functions that extra-ribosomal proteins appear to play in vivo make unraveling the formation of this macromolecular assemblage difficult. In this review, we outline with examples the multinodal landscape of factor-assisted mechanisms that influence ribosome synthesis in bacteria. We discuss in detail late-stage events that mediate correct ribosome formation and the transition to translation initiation and thereby ensure high-fidelity protein synthesis.
Collapse
Affiliation(s)
- Anusha Naganathan
- Department of Biology, University of Rochester, Rochester, New York, USA; ,
| | - Gloria M Culver
- Department of Biology, University of Rochester, Rochester, New York, USA; ,
- Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York, USA
| |
Collapse
|
5
|
Babu VMP, Sankari S, Ghosal A, Walker GC. A Mutant Era GTPase Suppresses Phenotypes Caused by Loss of Highly Conserved YbeY Protein in Escherichia coli. Front Microbiol 2022; 13:896075. [PMID: 35663862 PMCID: PMC9159920 DOI: 10.3389/fmicb.2022.896075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/13/2022] [Indexed: 12/03/2022] Open
Abstract
Ribosome assembly is a complex fundamental cellular process that involves assembling multiple ribosomal proteins and several ribosomal RNA species in a highly coordinated yet flexible and resilient manner. The highly conserved YbeY protein is a single-strand specific endoribonuclease, important for ribosome assembly, 16S rRNA processing, and ribosome quality control. In Escherichia coli, ybeY deletion results in pleiotropic phenotypes including slow growth, temperature sensitivity, accumulation of precursors of 16S rRNA, and impaired formation of fully assembled 70S subunits. Era, an essential highly conserved GTPase protein, interacts with many ribosomal proteins, and its depletion results in ribosome assembly defects. YbeY has been shown to interact with Era together with ribosomal protein S11. In this study, we have analyzed a suppressor mutation, era(T99I), that can partially suppress a subset of the multiple phenotypes of ybeY deletion. The era(T99I) allele was able to improve 16S rRNA processing and ribosome assembly at 37°C. However, it failed to suppress the temperature sensitivity and did not improve 16S rRNA stability. The era(T99I) allele was also unable to improve the 16S rRNA processing defects caused by the loss of ribosome maturation factors. We also show that era(T99I) increases the GroEL levels in the 30S ribosome fractions independent of YbeY. We propose that the mechanism of suppression is that the changes in Era's structure caused by the era(T99I) mutation affect its GTP/GDP cycle in a way that increases the half-life of RNA binding to Era, thereby facilitating alternative processing of the 16S RNA precursor. Taken together, this study offers insights into the role of Era and YbeY in ribosome assembly and 16S rRNA processing events.
Collapse
Affiliation(s)
| | | | | | - Graham C. Walker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States
| |
Collapse
|
6
|
Maksimova E, Kravchenko O, Korepanov A, Stolboushkina E. Protein Assistants of Small Ribosomal Subunit Biogenesis in Bacteria. Microorganisms 2022; 10:microorganisms10040747. [PMID: 35456798 PMCID: PMC9032327 DOI: 10.3390/microorganisms10040747] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/16/2022] [Accepted: 03/26/2022] [Indexed: 01/27/2023] Open
Abstract
Ribosome biogenesis is a fundamental and multistage process. The basic steps of ribosome assembly are the transcription, processing, folding, and modification of rRNA; the translation, folding, and modification of r-proteins; and consecutive binding of ribosomal proteins to rRNAs. Ribosome maturation is facilitated by biogenesis factors that include a broad spectrum of proteins: GTPases, RNA helicases, endonucleases, modification enzymes, molecular chaperones, etc. The ribosome assembly factors assist proper rRNA folding and protein–RNA interactions and may sense the checkpoints during the assembly to ensure correct order of this process. Inactivation of these factors is accompanied by severe growth phenotypes and accumulation of immature ribosomal subunits containing unprocessed rRNA, which reduces overall translation efficiency and causes translational errors. In this review, we focus on the structural and biochemical analysis of the 30S ribosomal subunit assembly factors RbfA, YjeQ (RsgA), Era, KsgA (RsmA), RimJ, RimM, RimP, and Hfq, which take part in the decoding-center folding.
Collapse
Affiliation(s)
| | | | - Alexey Korepanov
- Correspondence: (A.K.); (E.S.); Tel.: +7-925-7180670 (A.K.); +7-915-4791359 (E.S.)
| | - Elena Stolboushkina
- Correspondence: (A.K.); (E.S.); Tel.: +7-925-7180670 (A.K.); +7-915-4791359 (E.S.)
| |
Collapse
|
7
|
YbeY, éminence grise of ribosome biogenesis. Biochem Soc Trans 2021; 49:727-745. [PMID: 33929506 DOI: 10.1042/bst20200669] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/30/2022]
Abstract
YbeY is an ultraconserved small protein belonging to the unique heritage shared by most existing bacteria and eukaryotic organelles of bacterial origin, mitochondria and chloroplasts. Studied in more than a dozen of evolutionarily distant species, YbeY is invariably critical for cellular physiology. However, the exact mechanisms by which it exerts such penetrating influence are not completely understood. In this review, we attempt a transversal analysis of the current knowledge about YbeY, based on genetic, structural, and biochemical data from a wide variety of models. We propose that YbeY, in association with the ribosomal protein uS11 and the assembly GTPase Era, plays a critical role in the biogenesis of the small ribosomal subunit, and more specifically its platform region, in diverse genetic systems of bacterial type.
Collapse
|
8
|
Prossliner T, Gerdes K, Sørensen MA, Winther KS. Hibernation factors directly block ribonucleases from entering the ribosome in response to starvation. Nucleic Acids Res 2021; 49:2226-2239. [PMID: 33503254 PMCID: PMC7913689 DOI: 10.1093/nar/gkab017] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/03/2021] [Accepted: 01/11/2021] [Indexed: 11/18/2022] Open
Abstract
Ribosome hibernation is a universal translation stress response found in bacteria as well as plant plastids. The term was coined almost two decades ago and despite recent insights including detailed cryo-EM structures, the physiological role and underlying molecular mechanism of ribosome hibernation has remained unclear. Here, we demonstrate that Escherichia coli hibernation factors RMF, HPF and RaiA (HFs) concurrently confer ribosome hibernation. In response to carbon starvation and resulting growth arrest, we observe that HFs protect ribosomes at the initial stage of starvation. Consistently, a deletion mutant lacking all three factors (ΔHF) is severely inhibited in regrowth from starvation. ΔHF cells increasingly accumulate 70S ribosomes harbouring fragmented rRNA, while rRNA in wild-type 100S dimers is intact. RNA fragmentation is observed to specifically occur at HF-associated sites in 16S rRNA of assembled 70S ribosomes. Surprisingly, degradation of the 16S rRNA 3′-end is decreased in cells lacking conserved endoribonuclease YbeY and exoribonuclease RNase R suggesting that HFs directly block these ribonucleases from accessing target sites in the ribosome.
Collapse
Affiliation(s)
- Thomas Prossliner
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | | | - Michael Askvad Sørensen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | | |
Collapse
|
9
|
Summer S, Smirnova A, Gabriele A, Toth U, Fasemore AM, Förstner KU, Kuhn L, Chicher J, Hammann P, Mitulović G, Entelis N, Tarassov I, Rossmanith W, Smirnov A. YBEY is an essential biogenesis factor for mitochondrial ribosomes. Nucleic Acids Res 2020; 48:9762-9786. [PMID: 32182356 PMCID: PMC7515705 DOI: 10.1093/nar/gkaa148] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 12/11/2022] Open
Abstract
Ribosome biogenesis requires numerous trans-acting factors, some of which are deeply conserved. In Bacteria, the endoribonuclease YbeY is believed to be involved in 16S rRNA 3′-end processing and its loss was associated with ribosomal abnormalities. In Eukarya, YBEY appears to generally localize to mitochondria (or chloroplasts). Here we show that the deletion of human YBEY results in a severe respiratory deficiency and morphologically abnormal mitochondria as an apparent consequence of impaired mitochondrial translation. Reduced stability of 12S rRNA and the deficiency of several proteins of the small ribosomal subunit in YBEY knockout cells pointed towards a defect in mitochondrial ribosome biogenesis. The specific interaction of mitoribosomal protein uS11m with YBEY suggests that the latter helps to properly incorporate uS11m into the nascent small subunit in its late assembly stage. This scenario shows similarities with final stages of cytosolic ribosome biogenesis, and may represent a late checkpoint before the mitoribosome engages in translation.
Collapse
Affiliation(s)
- Sabrina Summer
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna A-1090, Austria
| | - Anna Smirnova
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Alessandro Gabriele
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Ursula Toth
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna A-1090, Austria
| | | | - Konrad U Förstner
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg 97080, Germany.,TH Köln - University of Applied Sciences, Faculty of Information Science and Communication Studies, Institute of Information Science, Cologne D-50678, Germany.,ZB MED - Information Centre for Life Sciences, Cologne D-50931, Germany
| | - Lauriane Kuhn
- Proteomics Platform Strasbourg-Esplanade, FRC1589, IBMC, CNRS, Strasbourg F-67000, France
| | - Johana Chicher
- Proteomics Platform Strasbourg-Esplanade, FRC1589, IBMC, CNRS, Strasbourg F-67000, France
| | - Philippe Hammann
- Proteomics Platform Strasbourg-Esplanade, FRC1589, IBMC, CNRS, Strasbourg F-67000, France
| | - Goran Mitulović
- Proteomics Core Facility, Clinical Department for Laboratory Medicine, Medical University of Vienna, Vienna A-1090, Austria
| | - Nina Entelis
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Ivan Tarassov
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| | - Walter Rossmanith
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna A-1090, Austria
| | - Alexandre Smirnov
- UMR7156 - Molecular Genetics, Genomics, Microbiology, University of Strasbourg, CNRS, Strasbourg F-67000, France
| |
Collapse
|
10
|
Abstract
RNA quality control pathways are critical for cell survival. Here, we describe a new surveillance process involved in the degradation of highly structured and stable ribosomal RNAs. The results demonstrated that the RNA chaperone Hfq and the 3'-5' exoribonuclease R mediate the elimination of detrimental rRNA fragments and are required for the correct processing of rRNA precursors. Escherichia coli cells lacking both Hfq and RNase R accumulate a high level of 16S- and 23S-derived rRNA fragments. Hfq and RNase R were also shown to participate in the maturation of 16S and 23S rRNA precursors. This correlates with the fact that in the absence of Hfq and RNase R, there are severe ribosome assembly defects and a sharp reduction in 70S ribosome levels. Hfq and RNase R may act independently or in a complex, as protein interaction studies revealed that these RNA-binding proteins can associate. This is the first demonstration that the well-conserved Hfq and RNase R proteins act on common regulatory pathways, unraveling previously unknown mechanisms of rRNA surveillance with important consequences for translation and cell survival.IMPORTANCE Quality control pathways that oversee the quality of stable RNA molecules are critical for the cell. In this work, we demonstrate, for the first time, a functional link between Hfq and RNase R in the processing and degradation of the highly structured rRNAs. These RNA-binding proteins are required for the maturation of 16S and 23S rRNAs and correct ribosome assembly. Furthermore, they participate in the degradation of rRNAs and clearance of toxic rRNA fragments from the cell. Our studies have also shown that Hfq and RNase R can form a complex. In summary, the cooperation between Hfq and RNase R in metabolic pathways of stable RNAs may represent a broader mechanism of RNA quality control, given the high conservation of these RNA-binding proteins throughout evolution.
Collapse
|
11
|
Overproduction of a Dominant Mutant of the Conserved Era GTPase Inhibits Cell Division in Escherichia coli. J Bacteriol 2020; 202:JB.00342-20. [PMID: 32817092 DOI: 10.1128/jb.00342-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/07/2020] [Indexed: 12/24/2022] Open
Abstract
Cell growth and division are coordinated, ensuring homeostasis under any given growth condition, with division occurring as cell mass doubles. The signals and controlling circuit(s) between growth and division are not well understood; however, it is known in Escherichia coli that the essential GTPase Era, which is growth rate regulated, coordinates the two functions and may be a checkpoint regulator of both. We have isolated a mutant of Era that separates its effect on growth and division. When overproduced, the mutant protein Era647 is dominant to wild-type Era and blocks division, causing cells to filament. Multicopy suppressors that prevent the filamentation phenotype of Era647 either increase the expression of FtsZ or decrease the expression of the Era647 protein. Excess Era647 induces complete delocalization of Z rings, providing an explanation for why Era647 induces filamentation, but this effect is probably not due to direct interaction between Era647 and FtsZ. The hypermorphic ftsZ* allele at the native locus can suppress the effects of Era647 overproduction, indicating that extra FtsZ is not required for the suppression, but another hypermorphic allele that accelerates cell division through periplasmic signaling, ftsL*, cannot. Together, these results suggest that Era647 blocks cell division by destabilizing the Z ring.IMPORTANCE All cells need to coordinate their growth and division, and small GTPases that are conserved throughout life play a key role in this regulation. One of these, Era, provides an essential function in the assembly of the 30S ribosomal subunit in Escherichia coli, but its role in regulating E. coli cell division is much less well understood. Here, we characterize a novel dominant negative mutant of Era (Era647) that uncouples these two activities when overproduced; it inhibits cell division by disrupting assembly of the Z ring, without significantly affecting ribosome production. The unique properties of this mutant should help to elucidate how Era regulates cell division and coordinates this process with ribosome biogenesis.
Collapse
|
12
|
Abstract
The increasing bacterial antibiotic resistance imposes a severe threat to human health. For the development of effective treatment and prevention strategies, it is critical to understand the mechanisms employed by bacteria to grow in the human body. Posttranscriptional regulation plays an important role in bacterial adaptation to environmental changes. RNases and small RNAs are key players in this regulation. In this study, we demonstrate critical roles of the RNase YbeY in the virulence of the pathogenic bacterium Pseudomonas aeruginosa. We further identify the small RNA ReaL as the direct target of YbeY and elucidate the YbeY-regulated pathway on the expression of bacterial virulence factors. Our results shed light on the complex regulatory network of P. aeruginosa and indicate that inference with the YbeY-mediated regulatory pathway might be a valid strategy for the development of a novel treatment strategy. Posttranscriptional regulation plays an essential role in the quick adaptation of pathogenic bacteria to host environments, and RNases play key roles in this process by modifying small RNAs and mRNAs. We find that the Pseudomonas aeruginosa endonuclease YbeY is required for rRNA processing and the bacterial virulence in a murine acute pneumonia model. Transcriptomic analyses reveal that knocking out the ybeY gene results in downregulation of oxidative stress response genes, including the catalase genes katA and katB. Consistently, the ybeY mutant is more susceptible to H2O2 and neutrophil-mediated killing. Overexpression of katA restores the bacterial tolerance to H2O2 and neutrophil killing as well as virulence. We further find that the downregulation of the oxidative stress response genes is due to defective expression of the stationary-phase sigma factor RpoS. We demonstrate an autoregulatory mechanism of RpoS and find that ybeY mutation increases the level of a small RNA, ReaL, which directly represses the translation of rpoS through the 5′ UTR of its mRNA and subsequently reduces the expression of the oxidative stress response genes. In vitro assays demonstrate direct degradation of ReaL by YbeY. Deletion of reaL or overexpression of rpoS in the ybeY mutant restores the bacterial tolerance to oxidative stress and the virulence. We also demonstrate that YbeZ binds to YbeY and is involved in the 16S rRNA processing and regulation of reaL and rpoS as well as the bacterial virulence. Overall, our results reveal pleiotropic roles of YbeY and the YbeY-mediated regulation of rpoS through ReaL.
Collapse
|
13
|
Babu VMP, Sankari S, Budnick JA, Caswell CC, Walker GC. Sinorhizobium meliloti YbeY is a zinc-dependent single-strand specific endoribonuclease that plays an important role in 16S ribosomal RNA processing. Nucleic Acids Res 2020; 48:332-348. [PMID: 31777930 PMCID: PMC6943124 DOI: 10.1093/nar/gkz1095] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/01/2019] [Accepted: 11/21/2019] [Indexed: 12/19/2022] Open
Abstract
Single-strand specific endoribonuclease YbeY has been shown to play an important role in the processing of the 3' end of the 16S rRNA in Escherichia coli. Lack of YbeY results in the accumulation of the 17S rRNA precursor. In contrast to a previous report, we show that Sinorhizobium meliloti YbeY exhibits endoribonuclease activity on single-stranded RNA substrate but not on the double-stranded substrate. This study also identifies the previously unknown metal ion involved in YbeY function to be Zn2+ and shows that the activity of YbeY is enhanced when the occupancy of zinc is increased. We have identified a pre-16S rRNA precursor that accumulates in the S. meliloti ΔybeY strain. We also show that ΔybeY mutant of Brucella abortus, a mammalian pathogen, also accumulates a similar pre-16S rRNA. The pre-16S species is longer in alpha-proteobacteria than in gamma-proteobacteria. We demonstrate that the YbeY from E. coli and S. meliloti can reciprocally complement the rRNA processing defect in a ΔybeY mutant of the other organism. These results establish YbeY as a zinc-dependent single-strand specific endoribonuclease that functions in 16S rRNA processing in both alpha- and gamma-proteobacteria.
Collapse
Affiliation(s)
- Vignesh M P Babu
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Siva Sankari
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - James A Budnick
- Department of Biomedical Sciences and Pathobiology, VA-MD College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, PA, USA
| | - Clayton C Caswell
- Department of Biomedical Sciences and Pathobiology, VA-MD College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | - Graham C Walker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
14
|
Razi A, Davis JH, Hao Y, Jahagirdar D, Thurlow B, Basu K, Jain N, Gomez-Blanco J, Britton RA, Vargas J, Guarné A, Woodson SA, Williamson JR, Ortega J. Role of Era in assembly and homeostasis of the ribosomal small subunit. Nucleic Acids Res 2019; 47:8301-8317. [PMID: 31265110 PMCID: PMC6736133 DOI: 10.1093/nar/gkz571] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/11/2019] [Accepted: 06/27/2019] [Indexed: 01/23/2023] Open
Abstract
Assembly factors provide speed and directionality to the maturation process of the 30S subunit in bacteria. To gain a more precise understanding of how these proteins mediate 30S maturation, it is important to expand on studies of 30S assembly intermediates purified from bacterial strains lacking particular maturation factors. To reveal the role of the essential protein Era in the assembly of the 30S ribosomal subunit, we analyzed assembly intermediates that accumulated in Era-depleted Escherichia coli cells using quantitative mass spectrometry, high resolution cryo-electron microscopy and in-cell footprinting. Our combined approach allowed for visualization of the small subunit as it assembled and revealed that with the exception of key helices in the platform domain, all other 16S rRNA domains fold even in the absence of Era. Notably, the maturing particles did not stall while waiting for the platform domain to mature and instead re-routed their folding pathway to enable concerted maturation of other structural motifs spanning multiple rRNA domains. We also found that binding of Era to the mature 30S subunit destabilized helix 44 and the decoding center preventing binding of YjeQ, another assembly factor. This work establishes Era’s role in ribosome assembly and suggests new roles in maintaining ribosome homeostasis.
Collapse
Affiliation(s)
- Aida Razi
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Joseph H Davis
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.,Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yumeng Hao
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Dushyant Jahagirdar
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Brett Thurlow
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S4K1, Canada
| | - Kaustuv Basu
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Nikhil Jain
- Department of Molecular Virology and Microbiology, Baylor College of Medicine,Houston, TX 77030, USA.,Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX 77030, USA
| | - Josue Gomez-Blanco
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Robert A Britton
- Department of Molecular Virology and Microbiology, Baylor College of Medicine,Houston, TX 77030, USA.,Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX 77030, USA
| | - Javier Vargas
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Alba Guarné
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 0B1 Canada
| | - Sarah A Woodson
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - James R Williamson
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.,Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| |
Collapse
|
15
|
Zuo R, Oliveira A, Bullita E, Torino MI, Padgett‐Pagliai KA, Gardner CL, Harrison NA, da Silva D, Merli ML, Gonzalez CF, Lorca GL. Identification of flavonoids as regulators of YbeY activity in
Liberibacter asiaticus. Environ Microbiol 2019; 21:4822-4835. [DOI: 10.1111/1462-2920.14831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/02/2019] [Accepted: 10/16/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Ran Zuo
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Aline Oliveira
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Enrica Bullita
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Maria Ines Torino
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Kaylie A. Padgett‐Pagliai
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Christopher L. Gardner
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Natalie A. Harrison
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Danilo da Silva
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Marcelo L. Merli
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Claudio F. Gonzalez
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| | - Graciela L. Lorca
- Microbiology and Cell Science Department, Genetics Institute, Institute of Food and Agricultural ScienceUniversity of Florida Gainesville Florida USA
| |
Collapse
|
16
|
Bennison DJ, Irving SE, Corrigan RM. The Impact of the Stringent Response on TRAFAC GTPases and Prokaryotic Ribosome Assembly. Cells 2019; 8:cells8111313. [PMID: 31653044 PMCID: PMC6912228 DOI: 10.3390/cells8111313] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/17/2019] [Accepted: 10/23/2019] [Indexed: 12/24/2022] Open
Abstract
Many facets of ribosome biogenesis and function, including ribosomal RNA (rRNA) transcription, 70S assembly and protein translation, are negatively impacted upon induction of a nutrient stress-sensing signalling pathway termed the stringent response. This stress response is mediated by the alarmones guanosine tetra- and penta-phosphate ((p)ppGpp), the accumulation of which leads to a massive cellular response that slows growth and aids survival. The 70S bacterial ribosome is an intricate structure, with assembly both complex and highly modular. Presiding over the assembly process is a group of P-loop GTPases within the TRAFAC (Translation Factor Association) superclass that are crucial for correct positioning of both early and late stage ribosomal proteins (r-proteins) onto the rRNA. Often described as 'molecular switches', members of this GTPase superfamily readily bind and hydrolyse GTP to GDP in a cyclic manner that alters the propensity of the GTPase to carry out a function. TRAFAC GTPases are considered to act as checkpoints to ribosome assembly, involved in binding to immature sections in the GTP-bound state, preventing further r-protein association until maturation is complete. Here we review our current understanding of the impact of the stringent response and (p)ppGpp production on ribosome maturation in prokaryotic cells, focusing on the inhibition of (p)ppGpp on GTPase-mediated subunit assembly, but also touching upon the inhibition of rRNA transcription and protein translation.
Collapse
Affiliation(s)
- Daniel J Bennison
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| | - Sophie E Irving
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| | - Rebecca M Corrigan
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| |
Collapse
|
17
|
Wood A, Irving SE, Bennison DJ, Corrigan RM. The (p)ppGpp-binding GTPase Era promotes rRNA processing and cold adaptation in Staphylococcus aureus. PLoS Genet 2019; 15:e1008346. [PMID: 31465450 PMCID: PMC6738653 DOI: 10.1371/journal.pgen.1008346] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/11/2019] [Accepted: 08/05/2019] [Indexed: 12/15/2022] Open
Abstract
Ribosome assembly cofactors are widely conserved across all domains of life. One such group, the ribosome-associated GTPases (RA-GTPase), act as molecular switches to coordinate ribosome assembly. We previously identified the Staphylococcus aureus RA-GTPase Era as a target for the stringent response alarmone (p)ppGpp, with binding leading to inhibition of GTPase activity. Era is highly conserved throughout the bacterial kingdom and is essential in many species, although the function of Era in ribosome assembly is unclear. Here we show that Era is not essential in S. aureus but is important for 30S ribosomal subunit assembly. Protein interaction studies reveal that Era interacts with the 16S rRNA endonuclease YbeY and the DEAD-box RNA helicase CshA. We determine that both Era and CshA are required for growth at suboptimal temperatures and rRNA processing. Era and CshA also form direct interactions with the (p)ppGpp synthetase RelSau, with RelSau positively impacting the GTPase activity of Era but negatively affecting the helicase activity of CshA. We propose that in its GTP-bound form, Era acts as a hub protein on the ribosome to direct enzymes involved in rRNA processing/degradation and ribosome subunit assembly to their site of action. This activity is impeded by multiple components of the stringent response, contributing to the slowed growth phenotype synonymous with this stress response pathway. The bacterial ribosome is an essential cellular component and as such is the target for a number of currently used antimicrobials. Correct assembly of this complex macromolecule requires a number of accessory enzymes, the functions of which are poorly characterised. Here we examine the function of Era, a GTPase enzyme involved in 30S ribosomal subunit biogenesis in the important human pathogen S. aureus. We uncover that Era is not an essential enzyme in S. aureus, as it is in many other species, but is important for correct ribosome assembly. In a bid to determine a function for this enzyme in ribosomal assembly, we identify a number of protein interaction partners with roles in ribosomal RNA maturation or degradation, supporting the idea that Era acts as a hub protein facilitating ribosomal biogenesis. We also uncover a link between Era and the (p)ppGpp synthetase RelSau, revealing an additional level of control of rRNA processing by the stringent response. With this study we elaborate on the functions of GTPases in ribosomal assembly, processes that are controlled at multiple points by the stringent response.
Collapse
Affiliation(s)
- Alison Wood
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Sophie E. Irving
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Daniel J. Bennison
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Rebecca M. Corrigan
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- * E-mail:
| |
Collapse
|
18
|
Bechhofer DH, Deutscher MP. Bacterial ribonucleases and their roles in RNA metabolism. Crit Rev Biochem Mol Biol 2019; 54:242-300. [PMID: 31464530 PMCID: PMC6776250 DOI: 10.1080/10409238.2019.1651816] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/22/2019] [Accepted: 07/31/2019] [Indexed: 12/16/2022]
Abstract
Ribonucleases (RNases) are mediators in most reactions of RNA metabolism. In recent years, there has been a surge of new information about RNases and the roles they play in cell physiology. In this review, a detailed description of bacterial RNases is presented, focusing primarily on those from Escherichia coli and Bacillus subtilis, the model Gram-negative and Gram-positive organisms, from which most of our current knowledge has been derived. Information from other organisms is also included, where relevant. In an extensive catalog of the known bacterial RNases, their structure, mechanism of action, physiological roles, genetics, and possible regulation are described. The RNase complement of E. coli and B. subtilis is compared, emphasizing the similarities, but especially the differences, between the two. Included are figures showing the three major RNA metabolic pathways in E. coli and B. subtilis and highlighting specific steps in each of the pathways catalyzed by the different RNases. This compilation of the currently available knowledge about bacterial RNases will be a useful tool for workers in the RNA field and for others interested in learning about this area.
Collapse
Affiliation(s)
- David H. Bechhofer
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Murray P. Deutscher
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
19
|
The RNase YbeY Is Vital for Ribosome Maturation, Stress Resistance, and Virulence of the Natural Genetic Engineer Agrobacterium tumefaciens. J Bacteriol 2019; 201:JB.00730-18. [PMID: 30885931 DOI: 10.1128/jb.00730-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/12/2019] [Indexed: 12/12/2022] Open
Abstract
Riboregulation involving regulatory RNAs, RNA chaperones, and ribonucleases is fundamental for the rapid adaptation of gene expression to changing environmental conditions. The gene coding for the RNase YbeY belongs to the minimal prokaryotic genome set and has a profound impact on physiology in a wide range of bacteria. Here, we show that the Agrobacterium tumefaciens ybeY gene is not essential. Deletion of the gene in the plant pathogen reduced growth, motility, and stress tolerance. Most interestingly, YbeY is crucial for A. tumefaciens-mediated T-DNA transfer and tumor formation. Comparative proteomics by using isobaric tags for relative and absolute quantitation (iTRAQ) revealed dysregulation of 59 proteins, many of which have previously been found to be dependent on the RNA chaperone Hfq. YbeY and Hfq have opposing effects on production of these proteins. Accumulation of a 16S rRNA precursor in the ybeY mutant suggests that A. tumefaciens YbeY is involved in rRNA processing. RNA coimmunoprecipitation-sequencing (RIP-Seq) showed binding of YbeY to the region immediately upstream of the 16S rRNA. Purified YbeY is an oligomer with RNase activity. It does not physically interact with Hfq and thus plays a partially overlapping but distinct role in the riboregulatory network of the plant pathogen.IMPORTANCE Although ybeY gene belongs to the universal bacterial core genome, its biological function is incompletely understood. Here, we show that YbeY is critical for fitness and host-microbe interaction in the plant pathogen Agrobacterium tumefaciens Consistent with the reported endoribonuclease activity of YbeY, A. tumefaciens YbeY acts as a RNase involved in maturation of 16S rRNA. This report adds a worldwide plant pathogen and natural genetic engineer of plants to the growing list of bacteria that require the conserved YbeY protein for host-microbe interaction.
Collapse
|