1
|
Fernández-García L, Gao X, Kirigo J, Song S, Battisti ME, Garcia-Contreras R, Tomas M, Guo Y, Wang X, Wood TK. Single-cell analysis reveals that cryptic prophage protease LfgB protects Escherichia coli during oxidative stress by cleaving antitoxin MqsA. Microbiol Spectr 2024; 12:e0347123. [PMID: 38206055 PMCID: PMC10846083 DOI: 10.1128/spectrum.03471-23] [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: 09/23/2023] [Accepted: 11/30/2023] [Indexed: 01/12/2024] Open
Abstract
Although toxin/antitoxin (TA) systems are ubiquitous, beyond phage inhibition and mobile element stabilization, their role in host metabolism is obscure. One of the best-characterized TA systems is MqsR/MqsA of Escherichia coli, which has been linked previously to protecting gastrointestinal species during the stress it encounters from the bile salt deoxycholate as it colonizes humans. However, some recent whole-population studies have challenged the role of toxins such as MqsR in bacterial physiology since the mqsRA locus is induced over a hundred-fold during stress, but a phenotype was not found upon its deletion. Here, we investigate further the role of MqsR/MqsA by utilizing single cells and demonstrate that upon oxidative stress, the TA system MqsR/MqsA has a heterogeneous effect on the transcriptome of single cells. Furthermore, we discovered that MqsR activation leads to induction of the poorly characterized yfjXY ypjJ yfjZF operon of cryptic prophage CP4-57. Moreover, deletion of yfjY makes the cells sensitive to H2O2, acid, and heat stress, and this phenotype was complemented. Hence, we recommend yfjY be renamed to lfgB (less fatality gene B). Critically, MqsA represses lfgB by binding the operon promoter, and LfgB is a protease that degrades MqsA to derepress rpoS and facilitate the stress response. Therefore, the MqsR/MqsA TA system facilitates the stress response through cryptic phage protease LfgB.IMPORTANCEThe roles of toxin/antitoxin systems in cell physiology are few and include phage inhibition and stabilization of genetic elements; yet, to date, there are no single-transcriptome studies for toxin/antitoxin systems and few insights for prokaryotes from this novel technique. Therefore, our results with this technique are important since we discover and characterize a cryptic prophage protease that is regulated by the MqsR/MqsA toxin/antitoxin system in order to regulate the host response to oxidative stress.
Collapse
Affiliation(s)
- Laura Fernández-García
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
- Microbiology Department, Hospital A Coruña (HUAC), A Coruña, Spain
- Microbiology Translational and Multidisciplinary (MicroTM)‐Research Institute Biomedical A Coruña (INIBIC) and Microbiology, University of A Coruña (UDC), A Coruña, Spain
| | - Xinyu Gao
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Institute of Oceanology, Chinese Academy of Sciences, Nansha, Guangzhou, China
- Guangdong Key Laboratory of Marine Materia Medica, Chinese Academy of Sciences, Nansha, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea, Chinese Academy of Sciences, China, Nansha,, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Joy Kirigo
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Sooyeon Song
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Animal Science, Jeonbuk National University, Jeonju-Si, Jellabuk-Do, South Korea
- Department of Agricultural Convergence Technology, Jeonbuk National University, Jeonju-Si, Jellabuk-Do, South Korea
| | - Michael E. Battisti
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Rodolfo Garcia-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, Mexico
| | - Maria Tomas
- Microbiology Department, Hospital A Coruña (HUAC), A Coruña, Spain
- Microbiology Translational and Multidisciplinary (MicroTM)‐Research Institute Biomedical A Coruña (INIBIC) and Microbiology, University of A Coruña (UDC), A Coruña, Spain
| | - Yunxue Guo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Institute of Oceanology, Chinese Academy of Sciences, Nansha, Guangzhou, China
- Guangdong Key Laboratory of Marine Materia Medica, Chinese Academy of Sciences, Nansha, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea, Chinese Academy of Sciences, China, Nansha,, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Nansha, Guangzhou, China
| | - Xiaoxue Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Institute of Oceanology, Chinese Academy of Sciences, Nansha, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Nansha, Guangzhou, China
| | - Thomas K. Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
| |
Collapse
|
2
|
Yu V, Ronzone E, Lord D, Peti W, Page R. MqsR is a noncanonical microbial RNase toxin that is inhibited by antitoxin MqsA via steric blockage of substrate binding. J Biol Chem 2022; 298:102535. [PMID: 36162504 PMCID: PMC9636575 DOI: 10.1016/j.jbc.2022.102535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/15/2022] [Accepted: 09/19/2022] [Indexed: 12/01/2022] Open
Abstract
The MqsRA toxin-antitoxin system is a component of the Escherichia coli stress response. Free MqsR, a ribonuclease, cleaves mRNAs containing a 5′-GC-3′ sequence causing a global shutdown of translation and the cell to enter a state of dormancy. Despite a general understanding of MqsR function, the molecular mechanism(s) by which MqsR binds and cleaves RNA and how one or more of these activities is inhibited by its cognate antitoxin MqsA is still poorly understood. Here, we used NMR spectroscopy coupled with mRNA cleavage assays to identify the molecular mechanism of MqsR substrate recognition and the MqsR residues that are essential for its catalytic activity. We show that MqsR preferentially binds substrates that contain purines in the −2 and −1 position relative to the MqsR consensus cleavage sequence and that two residues of MqsR, Tyr81, and Lys56 are strictly required for mRNA cleavage. We also show that MqsA inhibits MqsR activity by sterically blocking mRNA substrates from binding while leaving the active site fully accessible to mononucleotides. Together, these data identify the residues of MqsR that mediate RNA cleavage and reveal a novel mechanism that regulates MqsR substrate specificity.
Collapse
Affiliation(s)
- Victor Yu
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Erik Ronzone
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Dana Lord
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Wolfgang Peti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Rebecca Page
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut, USA.
| |
Collapse
|
3
|
Functional Characterization of the mazEF Toxin-Antitoxin System in the Pathogenic Bacterium Agrobacterium tumefaciens. Microorganisms 2021; 9:microorganisms9051107. [PMID: 34065548 PMCID: PMC8160871 DOI: 10.3390/microorganisms9051107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/14/2021] [Accepted: 05/16/2021] [Indexed: 11/16/2022] Open
Abstract
Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.
Collapse
|
4
|
Wood TK, Song S. Forming and waking dormant cells: The ppGpp ribosome dimerization persister model. Biofilm 2020; 2:100018. [PMID: 33447804 PMCID: PMC7798447 DOI: 10.1016/j.bioflm.2019.100018] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 02/07/2023] Open
Abstract
Procaryotes starve and face myriad stresses. The bulk population actively resists the stress, but a small population weathers the stress by entering a resting stage known as persistence. No mutations occur, and so persisters behave like wild-type cells upon removal of the stress and regrowth; hence, persisters are phenotypic variants. In contrast, resistant bacteria have mutations that allow cells to grow in the presence of antibiotics, and tolerant cells survive antibiotics better than actively-growing cells due to their slow growth (such as that of the stationary phase). In this review, we focus on the latest developments in studies related to the formation and resuscitation of persister cells and propose the guanosine pentaphosphate/tetraphosphate (henceforth ppGpp) ribosome dimerization persister (PRDP) model for entering and exiting the persister state.
Collapse
Affiliation(s)
- Thomas K. Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802-4400, USA
| | - Sooyeon Song
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802-4400, USA
| |
Collapse
|
6
|
Lobato-Márquez D, Díaz-Orejas R, García-Del Portillo F. Toxin-antitoxins and bacterial virulence. FEMS Microbiol Rev 2016; 40:592-609. [PMID: 27476076 DOI: 10.1093/femsre/fuw022] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2016] [Indexed: 12/25/2022] Open
Abstract
Bacterial virulence relies on a delicate balance of signals interchanged between the invading microbe and the host. This communication has been extensively perceived as a battle involving harmful molecules produced by the pathogen and host defenses. In this review, we focus on a largely unexplored element of this dialogue, as are toxin-antitoxin (TA) systems of the pathogen. TA systems are reported to respond to stresses that are also found in the host and, as a consequence, could modulate the physiology of the intruder microbe. This view is consistent with recent studies that demonstrate a contribution of distinct TA systems to virulence since their absence alters the course of the infection. TA loci are stress response modules that, therefore, could readjust pathogen metabolism to favor the generation of slow-growing or quiescent cells 'before' host defenses irreversibly block essential pathogen activities. Some toxins of these TA modules have been proposed as potential weapons used by the pathogen to act on host targets. We discuss all these aspects based on studies that support some TA modules as important regulators in the pathogen-host interface.
Collapse
Affiliation(s)
- Damián Lobato-Márquez
- Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain Centro de Investigaciones Biológicas-CSIC (CIB-CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Ramón Díaz-Orejas
- Centro de Investigaciones Biológicas-CSIC (CIB-CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Francisco García-Del Portillo
- Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| |
Collapse
|
7
|
Chowdhury N, Kwan BW, McGibbon LC, Babitzke P, Wood TK. Toxin MqsR cleaves single-stranded mRNA with various 5' ends. Microbiologyopen 2016; 5:370-7. [PMID: 26846703 PMCID: PMC4905990 DOI: 10.1002/mbo3.335] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/29/2015] [Accepted: 12/11/2015] [Indexed: 11/06/2022] Open
Abstract
Toxin/antitoxin (TA) systems are the means by which bacterial cells become persistent; that is, those cells that are tolerant to multiple environmental stresses such as antibiotics by becoming metabolically dormant. These persister cells are responsible for recalcitrant infections. Once toxins are activated by the inactivation of antitoxins (e.g., stress-triggered Lon degradation of the antitoxin), many toxins reduce metabolism by inhibiting translation (e.g., cleaving mRNA, reducing ATP). The MqsR/MqsA TA system of Escherichia coli cleaves mRNA to help the cell withstand oxidative and bile acid stress. Here, we investigated the role of secondary structure and 5' mRNA processing on MqsR degradation of mRNA and found that MqsR cleaves only single-stranded RNA at 5'-GCU sites and that MqsR is equally active against RNA with 5'-triphosphate, 5'-monophosphate, and 5'-hydroxyl groups.
Collapse
Affiliation(s)
- Nityananda Chowdhury
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, 16802-4400
| | - Brian W Kwan
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, 16802-4400
| | - Louise C McGibbon
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, 16802-4400.,Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, 16802-4400
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, 16802-4400.,Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, 16802-4400
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, 16802-4400.,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, 16802-4400.,Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, 16802-4400
| |
Collapse
|