1
|
Ekdahl AM, Julien T, Suraj S, Kribelbauer J, Tavazoie S, Freddolino PL, Contreras LM. Multiscale regulation of nutrient stress responses in Escherichia coli from chromatin structure to small regulatory RNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599902. [PMID: 38979244 PMCID: PMC11230228 DOI: 10.1101/2024.06.20.599902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Recent research has indicated the presence of heterochromatin-like regions of extended protein occupancy and transcriptional silencing of bacterial genomes. We utilized an integrative approach to track chromatin structure and transcription in E. coli K-12 across a wide range of nutrient conditions. In the process, we identified multiple loci which act similarly to facultative heterochromatin in eukaryotes, normally silenced but permitting expression of genes under specific conditions. We also found a strong enrichment of small regulatory RNAs (sRNAs) among the set of differentially expressed transcripts during nutrient stress. Using a newly developed bioinformatic pipeline, the transcription factors regulating sRNA expression were bioinformatically predicted, with experimental follow-up revealing novel relationships for 36 sRNA-transcription factors candidates. Direct regulation of sRNA expression was confirmed by mutational analysis for five sRNAs of metabolic interest: IsrB, CsrB and CsrC, GcvB, and GadY. Our integrative analysis thus reveals additional layers of complexity in the nutrient stress response in E. coli and provides a framework for revealing similar poorly understood regulatory logic in other organisms.
Collapse
Affiliation(s)
- Alyssa M Ekdahl
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Tatiana Julien
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Sahana Suraj
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Judith Kribelbauer
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
| | - Saeed Tavazoie
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
| | - P Lydia Freddolino
- Department of Biological Chemistry and Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| |
Collapse
|
2
|
Hsu JE, Matsen FA, Whitson AJ, Waalkes A, Almazan J, Bourassa LA, Salipante SJ, Long DR. 2023 Neer Award for Basic Science: Genetics of Cutibacterium acnes in revision shoulder arthroplasty: a large-scale bacterial whole-genome sequencing study. J Shoulder Elbow Surg 2024:S1058-2746(24)00241-6. [PMID: 38604398 DOI: 10.1016/j.jse.2024.02.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/24/2024] [Indexed: 04/13/2024]
Abstract
BACKGROUND Cutibacterium acnes is the bacterium most commonly responsible for shoulder periprosthetic joint infection (PJI) and is often cultured from samples obtained at the time of revision for failed shoulder arthroplasty. We sought to determine whether these bacteria originate from the patient or from exogenous sources. We also sought to identify which C. acnes genetic traits were associated with the development of shoulder PJI. METHODS We performed bacterial whole-genome sequencing of C. acnes from a single-institution repository of cultures obtained before or during primary and revision shoulder arthroplasty and correlated the molecular epidemiology and genetic content of strains with clinical features of infection. RESULTS A total of 341 isolates collected over a 4-year period from 88 patients were sequenced. C. acnes cultured from surgical specimens demonstrated significant similarity to the strains colonizing the skin of the same patient (P < .001). Infrequently, there was evidence of strains shared across unrelated patients, suggesting that exogenous sources of C. acnes culture-positivity were uncommon. Phylotypes IB and II were modestly associated with clinical features of PJI, but all phylotypes appeared inherently capable of causing disease. Chronic shoulder PJI was associated with the absence of common C. acnes genes involved in bacterial quorum-sensing (luxS, tqsA). CONCLUSION C. acnes strains cultured from deep intraoperative sources during revision shoulder arthroplasty demonstrate strong genetic similarity to the strains colonizing a patient's skin. Some phylotypes of C. acnes commonly colonizing human skin are modestly more virulent than others, but all phylotypes have a capacity for PJI. C. acnes cultured from cases of PJI commonly demonstrated genetic hallmarks associated with adaptation from acute to chronic phases of infection. This is the strongest evidence to date supporting the role of the patient's own, cutaneous C. acnes strains in the pathogenesis of shoulder arthroplasty infection. Our findings support the importance of further research focused on perioperative decolonization and management of endogenous bacteria that are likely to be introduced into the arthroplasty wound at the time of skin incision.
Collapse
Affiliation(s)
- Jason E Hsu
- Department of Orthopaedics and Sports Medicine, University of Washington Medical Center, Seattle, WA, USA.
| | - Frederick A Matsen
- Department of Orthopaedics and Sports Medicine, University of Washington Medical Center, Seattle, WA, USA
| | - Anastasia J Whitson
- Department of Orthopaedics and Sports Medicine, University of Washington Medical Center, Seattle, WA, USA
| | - Adam Waalkes
- Department of Laboratory Medicine & Pathology, University of Washington Medical Center, Seattle, WA, USA
| | - Jared Almazan
- Department of Laboratory Medicine & Pathology, University of Washington Medical Center, Seattle, WA, USA
| | - Lori A Bourassa
- Department of Laboratory Medicine & Pathology, University of Washington Medical Center, Seattle, WA, USA
| | - Stephen J Salipante
- Department of Laboratory Medicine & Pathology, University of Washington Medical Center, Seattle, WA, USA
| | - Dustin R Long
- Department of Anesthesiology & Pain Medicine, University of Washington Medical Center, Seattle, WA, USA
| |
Collapse
|
3
|
Lavado-Benito C, Murillo J, Martínez-Gil M, Ramos C, Rodríguez-Moreno L. GacA reduces virulence and increases competitiveness in planta in the tumorigenic olive pathogen Pseudomonas savastanoi pv. savastanoi. FRONTIERS IN PLANT SCIENCE 2024; 15:1347982. [PMID: 38375080 PMCID: PMC10875052 DOI: 10.3389/fpls.2024.1347982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/08/2024] [Indexed: 02/21/2024]
Abstract
GacS/GacA is a widely distributed two-component system playing an essential role as a key global regulator, although its characterization in phytopathogenic bacteria has been deeply biased, being intensively studied in pathogens of herbaceous plants but barely investigated in pathogens of woody hosts. P. savastanoi pv. savastanoi (Psv) is characterized by inducing tumours in the stem and branches of olive trees. In this work, the model strain Psv NCPPB 3335 and a mutant derivative with a complete deletion of gene gacA were subjected to RNA-Seq analyses in a minimum medium and a medium mimicking in planta conditions, accompanied by RT-qPCR analyses of selected genes and phenotypic assays. These experiments indicated that GacA participates in the regulation of at least 2152 genes in strain NCPPB 3335, representing 37.9 % of the annotated CDSs. GacA also controls the expression of diverse rsm genes, and modulates diverse phenotypes, including motility and resistance to oxidative stresses. As occurs with other P. syringae pathovars of herbaceous plants, GacA regulates the expression of the type III secretion system and cognate effectors. In addition, GacA also regulates the expression of WHOP genes, specifically encoded in P. syringe strains isolated from woody hosts, and genes for the biosynthesis of phytohormones. A gacA mutant of NCPPB 3335 showed increased virulence, producing large immature tumours with high bacterial populations, but showed a significantly reduced competitiveness in planta. Our results further extend the role of the global regulator GacA in the virulence and fitness of a P. syringae pathogen of woody hosts.
Collapse
Affiliation(s)
- Carla Lavado-Benito
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Jesús Murillo
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra (UPNA), Edificio de Agrobiotecnología, Mutilva Baja, Spain
| | - Marta Martínez-Gil
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| |
Collapse
|
4
|
Nava-Galeana J, Núñez C, Bustamante VH. Proteomic analysis reveals the global effect of the BarA/SirA-Csr regulatory cascade in Salmonella Typhimurium grown in conditions that favor the expression of invasion genes. J Proteomics 2023; 286:104960. [PMID: 37451358 DOI: 10.1016/j.jprot.2023.104960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/27/2023] [Indexed: 07/18/2023]
Abstract
In many bacteria, the BarA/SirA and Csr regulatory systems control expression of genes encoding a wide variety of cellular functions. The BarA/SirA two-component system induces the expression of CsrB and CsrC, two small non-coding RNAs that sequester CsrA, a protein that binds to target mRNAs and thus negatively or positively regulates their expression. BarA/SirA and CsrB/C induce expression of the Salmonella Pathogenicity Island 1 (SPI-1) genes required for Salmonella invasion of host cells. To further investigate the regulatory role of the BarA/SirA and Csr systems in Salmonella, we performed LC-MS/MS proteomic analysis using the WT S. Typhimurium strain and its derived ΔsirA and ΔcsrB ΔcsrC mutants grown in SPI-1-inducing conditions. The expression of 164 proteins with a wide diversity, or unknown, functions was significantly affected positively or negatively by the absence of SirA and/or CsrB/C. Interestingly, 19 proteins were identified as new targets for SirA-CsrB/C. Our results support that SirA and CsrB/C act in a cascade fashion to regulate gene expression in S. Typhimurium in the conditions tested. Notably, our results show that SirA-CsrB/C-CsrA controls expression of proteins required for the replication of Salmonella in the intestinal lumen, in an opposite way to its control exerted on the SPI-1 proteins. SIGNIFICANCE: The BarA/SirA and Csr global regulatory systems control a wide range of cellular processes, including the expression of virulence genes. For instance, in Salmonella, BarA/SirA and CsrB/C positively regulate expression of the SPI-1 genes, which are required for Salmonella invasion to host cells. In this study, by performing a proteomic analysis, we identified 164 proteins whose expression was positively or negatively controlled by SirA and CsrB/C in SPI-1-inducing conditions, including 19 new possible targets of these systems. Our results support the action of SirA and CsrB/C in a cascade fashion to control different cellular processes in Salmonella. Interestingly, our data indicate that SirA-CsrB/C-CsrA controls inversely the expression of proteins required for invasion of the intestinal epithelium and for replication in the intestinal lumen, which suggests a role for this regulatory cascade as a molecular switch for Salmonella virulence. Thus, our study further expands the insight into the regulatory mechanisms governing the virulence and physiology of an important pathogen.
Collapse
Affiliation(s)
- Jessica Nava-Galeana
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico
| | - Cinthia Núñez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico
| | - Víctor H Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico.
| |
Collapse
|
5
|
Nava-Galeana J, Yakhnin H, Babitzke P, Bustamante VH. CsrA Positively and Directly Regulates the Expression of the pdu, pocR, and eut Genes Required for the Luminal Replication of Salmonella Typhimurium. Microbiol Spectr 2023; 11:e0151623. [PMID: 37358421 PMCID: PMC10433801 DOI: 10.1128/spectrum.01516-23] [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: 04/10/2023] [Accepted: 05/26/2023] [Indexed: 06/27/2023] Open
Abstract
Enteric pathogens, such as Salmonella, have evolved to thrive in the inflamed gut. Genes located within the Salmonella pathogenicity island 1 (SPI-1) mediate the invasion of cells from the intestinal epithelium and the induction of an intestinal inflammatory response. Alternative electron acceptors become available in the inflamed gut and are utilized by Salmonella for luminal replication through the metabolism of propanediol and ethanolamine, using the enzymes encoded by the pdu and eut genes. The RNA-binding protein CsrA inhibits the expression of HilD, which is the central transcriptional regulator of the SPI-1 genes. Previous studies suggest that CsrA also regulates the expression of the pdu and eut genes, but the mechanism for this regulation is unknown. In this work, we show that CsrA positively regulates the pdu genes by binding to the pocR and pduA transcripts as well as the eut genes by binding to the eutS transcript. Furthermore, our results show that the SirA-CsrB/CsrC-CsrA regulatory cascade controls the expression of the pdu and eut genes mediated by PocR or EutR, which are the positive AraC-like transcriptional regulators for the pdu and eut genes, respectively. By oppositely regulating the expression of genes for invasion and for luminal replication, the SirA-CsrB/CsrC-CsrA regulatory cascade could be involved in the generation of two Salmonella populations that cooperate for intestinal colonization and transmission. Our study provides new insight into the regulatory mechanisms that govern Salmonella virulence. IMPORTANCE The regulatory mechanisms that control the expression of virulence genes are essential for bacteria to infect hosts. Salmonella has developed diverse regulatory mechanisms to colonize the host gut. For instance, the SirA-CsrB/CsrC-CsrA regulatory cascade controls the expression of the SPI-1 genes, which are required for this bacterium to invade intestinal epithelium cells and for the induction of an intestinal inflammatory response. In this study, we determine the mechanisms by which the SirA-CsrB/CsrC-CsrA regulatory cascade controls the expression of the pdu and eut genes, which are necessary for the replication of Salmonella in the intestinal lumen. Thus, our data, together with the results of previous reports, indicate that the SirA-CsrB/CsrC-CsrA regulatory cascade has an important role in the intestinal colonization by Salmonella.
Collapse
Affiliation(s)
- Jessica Nava-Galeana
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Víctor H. Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| |
Collapse
|
6
|
Kim B, Gurung S, Han SR, Lee JH, Oh TJ. Comparative Genomic Analysis of Biofilm-Forming Polar Microbacterium sp. Strains PAMC22086 and PAMC21962 Isolated from Extreme Habitats. Microorganisms 2023; 11:1757. [PMID: 37512929 PMCID: PMC10384088 DOI: 10.3390/microorganisms11071757] [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: 05/11/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
The members of Microbacterium isolated from different environments are known to form peptidoglycan. In this study, we compared the biofilm-forming abilities of Microbacterium sp. PAMC22086 (PAMC22086), which was isolated from the soil in the South Shetland Islands and Microbacterium sp. PAMC21962 (PAMC21962), which was isolated from algae in the South Shetland Islands. The analysis of average nucleotide identity and phylogeny of PAMC22086 revealed a 97% similarity to Microbacterium oxydans VIU2A, while PAMC21962 showed a 99.1% similarity to Microbacterium hominis SGAir0570. For the comparative genomic analysis of PAMC22086 and PAMC21962, the genes related to biofilm formation were identified using EggNOG and KEGG pathway databases. The genes possessed by both PAMC22086 and PAMC21962 are cpdA, phnB, rhlC, and glgC, which regulate virulence, biofilm formation, and multicellular structure. Among the genes indirectly involved in biofilm formation, unlike PAMC21962, PAMC22086 possessed csrA, glgC, and glgB, which are responsible for attachment and glycogen biosynthesis. Additionally, in PAMC22086, additional functional genes rsmA, which is involved in mobility and polysaccharide production, and dksA, GTPase, and oxyR, which play roles in cell cycle and stress response, were identified. In addition, the biofilm-forming ability of the two isolates was examined in vivo using the standard crystal violet staining technique, and morphological differences in the biofilm were investigated. It is evident from the different distribution of biofilm-associated genes between the two strains that the bacteria can survive in different niches by employing distinct strategies. Both strains exhibit distinct morphologies. PAMC22086 forms a biofilm that attaches to the side, while PAMC21962 indicates growth starting from the center. The biofilm formation-related genes in Microbacterium are not well understood. However, it has been observed that Microbacterium species form biofilm regardless of the number of genes they possess. Through comparison between different Microbacterium species, it was revealed that specific core genes are involved in cell adhesion, which plays a crucial role in biofilm formation. This study provides a comprehensive profile of the Microbacterium genus's genomic features and a preliminary understanding of biofilm in this genus, laying the foundation for further research.
Collapse
Affiliation(s)
- Byeollee Kim
- Department of Life Science and Biochemical Engineering, SunMoon University, Asan 31460, Republic of Korea
| | - Saru Gurung
- Department of Life Science and Biochemical Engineering, SunMoon University, Asan 31460, Republic of Korea
| | - So-Ra Han
- Bio Big Data-Based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, Republic of Korea
- Genome-Based BioIT Convergence Institute, Asan 31460, Republic of Korea
| | - Jun-Hyuck Lee
- Research Unit of Cryogenic Novel Materials, Korea Polar Research Institute, Incheon 21990, Republic of Korea
| | - Tae-Jin Oh
- Department of Life Science and Biochemical Engineering, SunMoon University, Asan 31460, Republic of Korea
- Bio Big Data-Based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, Republic of Korea
- Genome-Based BioIT Convergence Institute, Asan 31460, Republic of Korea
- Department of Pharmaceutical Engineering and Biotechnology, SunMoon University, Asan 31460, Republic of Korea
| |
Collapse
|
7
|
Contreras FU, Camacho MI, Pannuri A, Romeo T, Alvarez AF, Georgellis D. Spatiotemporal regulation of the BarA/UvrY two-component signaling system. J Biol Chem 2023:104835. [PMID: 37201582 DOI: 10.1016/j.jbc.2023.104835] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/25/2023] [Accepted: 05/03/2023] [Indexed: 05/20/2023] Open
Abstract
The BarA/UvrY two-component signal transduction system mediates adaptive responses of Escherichia coli to changes in growth stage. At late exponential growth phase, the BarA sensor kinase auto-phosphorylates and transphosphorylates UvrY, which activates transcription of the CsrB and CsrC noncoding RNAs. CsrB and CsrC, in turn, sequester and antagonize the RNA binding protein CsrA, which post-transcriptionally regulates translation and/or stability of its target mRNAs. Here, we provide evidence that, during stationary phase of growth, the HflKC complex recruits BarA to the poles of the cells, and silences its kinase activity. Moreover, we show that, during the exponential phase of growth, CsrA inhibits hflK and hflC expression, thereby enabling BarA activation upon encountering its stimulus. Thus, in addition to temporal control of BarA activity, spatial regulation is demonstrated.
Collapse
Affiliation(s)
- Fernanda Urias Contreras
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México D.F., México
| | - Martha I Camacho
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México D.F., México
| | - Archana Pannuri
- Department of Microbiology and Cell Science, PO Box 110700, University of Florida, Gainesville, FL 32611-0700, USA
| | | | - Adrian F Alvarez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México D.F., México
| | - Dimitris Georgellis
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México D.F., México.
| |
Collapse
|
8
|
Wu P, Wang Q, Yang Q, Feng X, Liu X, Sun H, Yan J, Kang C, Liu B, Liu Y, Yang B. A Novel Role of the Two-Component System Response Regulator UvrY in Enterohemorrhagic Escherichia coli O157:H7 Pathogenicity Regulation. Int J Mol Sci 2023; 24:ijms24032297. [PMID: 36768620 PMCID: PMC9916836 DOI: 10.3390/ijms24032297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/16/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important human pathogen causing severe diseases, such as hemorrhagic colitis and lethal hemolytic uremic syndrome. The signal-sensing capability of EHEC O157:H7 at specific host colonization sites via different two-component systems (TCSs) is closely related to its pathogenicity during infection. However, the types of systems involved and the regulatory mechanisms are not fully understood. Here, we investigated the function of the TCS BarA/UvrY regulator UvrY in the pathogenicity regulation of EHEC O157:H7. Our results showed that UvrY acts as a positive regulator of EHEC O157:H7 for cellular adherence and mouse colonization through the transcriptional activation of the locus for enterocyte effacement (LEE) pathogenic genes. Furthermore, this regulation is mediated by the LEE island master regulator, Ler. Our results highlight the significance of UvrY in EHEC O157:H7 pathogenicity and underline the unknown importance of BarA/UvrY in colonization establishment and intestinal adaptability during infection.
Collapse
Affiliation(s)
- Pan Wu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Qian Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Qian Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Xiaohui Feng
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Xingmei Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Hongmin Sun
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Jun Yan
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Chenbo Kang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
| | - Bin Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
- Nankai International Advanced Research Institute, Nankai University, Shenzhen 518000, China
| | - Yutao Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
- Nankai International Advanced Research Institute, Nankai University, Shenzhen 518000, China
- Correspondence: (Y.L.); (B.Y.)
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China
- Correspondence: (Y.L.); (B.Y.)
| |
Collapse
|
9
|
Mahendran G, Jayasinghe OT, Thavakumaran D, Arachchilage GM, Silva GN. Key players in regulatory RNA realm of bacteria. Biochem Biophys Rep 2022; 30:101276. [PMID: 35592614 PMCID: PMC9111926 DOI: 10.1016/j.bbrep.2022.101276] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/30/2022] [Accepted: 05/04/2022] [Indexed: 11/30/2022] Open
Abstract
Precise regulation of gene expression is crucial for living cells to adapt for survival in diverse environmental conditions. Among the common cellular regulatory mechanisms, RNA-based regulators play a key role in all domains of life. Discovery of regulatory RNAs have made a paradigm shift in molecular biology as many regulatory functions of RNA have been identified beyond its canonical roles as messenger, ribosomal and transfer RNA. In the complex regulatory RNA network, riboswitches, small RNAs, and RNA thermometers can be identified as some of the key players. Herein, we review the discovery, mechanism, and potential therapeutic use of these classes of regulatory RNAs mainly found in bacteria. Being highly adaptive organisms that inhabit a broad range of ecological niches, bacteria have adopted tight and rapid-responding gene regulation mechanisms. This review aims to highlight how bacteria utilize versatile RNA structures and sequences to build a sophisticated gene regulation network. The three major classes of prokaryotic ncRNAs and their characterized mechanisms of operation in gene regulation. sRNAs emerging as major players in global gene regulatory networks. Riboswitch mediated gene control mechanisms through on/off switches in response to ligand binding. RNA thermo sensors for temperature-dependent gene expression. Therapeutic importance of ncRNAs and computational approaches involved in the discovery of ncRNAs.
Collapse
Affiliation(s)
- Gowthami Mahendran
- Department of Chemistry, University of Colombo, Colombo, Sri Lanka
- Department of Chemistry and Biochemistry, University of Notre Dame, IN, 46556, USA
| | - Oshadhi T. Jayasinghe
- Department of Chemistry, University of Colombo, Colombo, Sri Lanka
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Dhanushika Thavakumaran
- Department of Chemistry, University of Colombo, Colombo, Sri Lanka
- Department of Chemistry and Biochemistry, University of Notre Dame, IN, 46556, USA
| | - Gayan Mirihana Arachchilage
- Howard Hughes Medical Institute, Yale University, New Haven, CT, 06520-8103, USA
- PTC Therapeutics Inc, South Plainfield, NJ, 07080, USA
| | - Gayathri N. Silva
- Department of Chemistry, University of Colombo, Colombo, Sri Lanka
- Corresponding author.
| |
Collapse
|
10
|
Tierrafría VH, Rioualen C, Salgado H, Lara P, Gama-Castro S, Lally P, Gómez-Romero L, Peña-Loredo P, López-Almazo AG, Alarcón-Carranza G, Betancourt-Figueroa F, Alquicira-Hernández S, Polanco-Morelos JE, García-Sotelo J, Gaytan-Nuñez E, Méndez-Cruz CF, Muñiz LJ, Bonavides-Martínez C, Moreno-Hagelsieb G, Galagan JE, Wade JT, Collado-Vides J. RegulonDB 11.0: Comprehensive high-throughput datasets on transcriptional regulation in Escherichia coli K-12. Microb Genom 2022; 8:mgen000833. [PMID: 35584008 PMCID: PMC9465075 DOI: 10.1099/mgen.0.000833] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 04/24/2022] [Indexed: 01/23/2023] Open
Abstract
Genomics has set the basis for a variety of methodologies that produce high-throughput datasets identifying the different players that define gene regulation, particularly regulation of transcription initiation and operon organization. These datasets are available in public repositories, such as the Gene Expression Omnibus, or ArrayExpress. However, accessing and navigating such a wealth of data is not straightforward. No resource currently exists that offers all available high and low-throughput data on transcriptional regulation in Escherichia coli K-12 to easily use both as whole datasets, or as individual interactions and regulatory elements. RegulonDB (https://regulondb.ccg.unam.mx) began gathering high-throughput dataset collections in 2009, starting with transcription start sites, then adding ChIP-seq and gSELEX in 2012, with up to 99 different experimental high-throughput datasets available in 2019. In this paper we present a radical upgrade to more than 2000 high-throughput datasets, processed to facilitate their comparison, introducing up-to-date collections of transcription termination sites, transcription units, as well as transcription factor binding interactions derived from ChIP-seq, ChIP-exo, gSELEX and DAP-seq experiments, besides expression profiles derived from RNA-seq experiments. For ChIP-seq experiments we offer both the data as presented by the authors, as well as data uniformly processed in-house, enhancing their comparability, as well as the traceability of the methods and reproducibility of the results. Furthermore, we have expanded the tools available for browsing and visualization across and within datasets. We include comparisons against previously existing knowledge in RegulonDB from classic experiments, a nucleotide-resolution genome viewer, and an interface that enables users to browse datasets by querying their metadata. A particular effort was made to automatically extract detailed experimental growth conditions by implementing an assisted curation strategy applying Natural language processing and machine learning. We provide summaries with the total number of interactions found in each experiment, as well as tools to identify common results among different experiments. This is a long-awaited resource to make use of such wealth of knowledge and advance our understanding of the biology of the model bacterium E. coli K-12.
Collapse
Affiliation(s)
- Víctor H. Tierrafría
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Claire Rioualen
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Heladia Salgado
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Paloma Lara
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Socorro Gama-Castro
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Patrick Lally
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Laura Gómez-Romero
- Instituto Nacional de Medicina Genómica, INMEGEN, Periférico Sur 4809, Arenal Tepepan, Tlalpan 14610, CDMX, Mexico
| | - Pablo Peña-Loredo
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Andrés G. López-Almazo
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Gabriel Alarcón-Carranza
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Felipe Betancourt-Figueroa
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Shirley Alquicira-Hernández
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - J. Enrique Polanco-Morelos
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Jair García-Sotelo
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de México, Querétaro 76230, Querétaro, Mexico
| | - Estefani Gaytan-Nuñez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Carlos-Francisco Méndez-Cruz
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Luis J. Muñiz
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - César Bonavides-Martínez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
| | - Gabriel Moreno-Hagelsieb
- Department of Biology, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON N2L 3C5, Canada
| | - James E. Galagan
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Joseph T. Wade
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
- Department of Biomedical Sciences, University at Albany, SUNY, Albany, NY, USA
| | - Julio Collado-Vides
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca 62210, Morelos, Mexico
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Universitat Pompeu Fabra(UPF), Barcelona, Spain
| |
Collapse
|
11
|
Zoccarato L, Sher D, Miki T, Segrè D, Grossart HP. A comparative whole-genome approach identifies bacterial traits for marine microbial interactions. Commun Biol 2022; 5:276. [PMID: 35347228 PMCID: PMC8960797 DOI: 10.1038/s42003-022-03184-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/30/2021] [Indexed: 12/11/2022] Open
Abstract
Microbial interactions shape the structure and function of microbial communities with profound consequences for biogeochemical cycles and ecosystem health. Yet, most interaction mechanisms are studied only in model systems and their prevalence is unknown. To systematically explore the functional and interaction potential of sequenced marine bacteria, we developed a trait-based approach, and applied it to 473 complete genomes (248 genera), representing a substantial fraction of marine microbial communities. We identified genome functional clusters (GFCs) which group bacterial taxa with common ecology and life history. Most GFCs revealed unique combinations of interaction traits, including the production of siderophores (10% of genomes), phytohormones (3-8%) and different B vitamins (57-70%). Specific GFCs, comprising Alpha- and Gammaproteobacteria, displayed more interaction traits than expected by chance, and are thus predicted to preferentially interact synergistically and/or antagonistically with bacteria and phytoplankton. Linked trait clusters (LTCs) identify traits that may have evolved to act together (e.g., secretion systems, nitrogen metabolism regulation and B vitamin transporters), providing testable hypotheses for complex mechanisms of microbial interactions. Our approach translates multidimensional genomic information into an atlas of marine bacteria and their putative functions, relevant for understanding the fundamental rules that govern community assembly and dynamics.
Collapse
Affiliation(s)
- Luca Zoccarato
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), 16775, Stechlin, Germany.
| | - Daniel Sher
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, 3498838, Haifa, Israel.
| | - Takeshi Miki
- Faculty of Advanced Science and Technology, Ryukoku University, 520-2194, Otsu, Japan
| | - Daniel Segrè
- Departments of Biology, Biomedical Engineering, Physics, Boston University, 02215, Boston, MA, USA
- Bioinformatics Program & Biological Design Center, Boston University, 02215, Boston, MA, USA
| | - Hans-Peter Grossart
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), 16775, Stechlin, Germany.
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195, Berlin, Germany.
- Institute of Biochemistry and Biology, Potsdam University, 14476, Potsdam, Germany.
| |
Collapse
|
12
|
uvrY deletion and acetate reduce gut colonization of Crohn's disease-associated adherent-invasive Escherichia coli by decreasing expression of type 1 fimbriae. Infect Immun 2022; 90:e0066221. [PMID: 34978926 DOI: 10.1128/iai.00662-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Adherent-invasive Escherichia coli (AIEC) is involved in onset and/or exacerbation of Crohn's disease. AIEC adapts to the gut environment by altering gene-expression programs, leading to successful gut-lumen colonization. However, the underlying mechanism of gut colonization is still far from clarified. Here, we show the role of UvrY, a response regulator of bacterial two-component signal transduction systems, in AIEC gut colonization. An AIEC mutant lacking the uvrY gene exhibited impairment of competitive colonization in the murine intestinal tract. UvrY contributes to functional expression of type 1 fimbriae by activating expression of small RNA CsrB, which confers adherence and invasion into epithelial cells on AIEC. In contrast, acetate suppresses the UvrY-dependent expression of type 1 fimbriae, resulting in less efficient cell invasion and attenuated gut colonization. Our findings might lead to therapeutic interventions for CD, in which inhibitions of UvrY activation and acetate supplementation reduce the colonization levels of AIEC by decreasing type-1 fimbriae expression.
Collapse
|
13
|
Lai YJ, Yakhnin H, Pannuri A, Pourciau C, Babitzke P, Romeo T. CsrA regulation via binding to the base-pairing small RNA Spot 42. Mol Microbiol 2022; 117:32-53. [PMID: 34107125 PMCID: PMC10000020 DOI: 10.1111/mmi.14769] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/26/2021] [Accepted: 06/08/2021] [Indexed: 02/03/2023]
Abstract
The carbon storage regulator system and base-pairing small RNAs (sRNAs) represent two predominant modes of bacterial post-transcriptional regulation, which globally influence gene expression. Binding of CsrA protein to the 5' UTR or initial mRNA coding sequences can affect translation, RNA stability, and/or transcript elongation. Base-pairing sRNAs also regulate these processes, often requiring assistance from the RNA chaperone Hfq. Transcriptomics studies in Escherichia coli have identified many new CsrA targets, including Spot 42 and other base-pairing sRNAs. Spot 42 synthesis is repressed by cAMP-CRP, induced by the presence of glucose, and Spot 42 post-transcriptionally represses operons that facilitate metabolism of nonpreferred carbon sources. CsrA activity is also increased by glucose via effects on CsrA sRNA antagonists, CsrB/C. Here, we elucidate a mechanism wherein CsrA binds to and protects Spot 42 sRNA from RNase E-mediated cleavage. This protection leads to enhanced repression of srlA by Spot 42, a gene required for sorbitol uptake. A second, independent mechanism by which CsrA represses srlA is by binding to and inhibiting translation of srlM mRNA, encoding a transcriptional activator of srlA. Our findings demonstrate a novel means of regulation, by CsrA binding to a sRNA, and indicate that such interactions can help to shape complex bacterial regulatory circuitry.
Collapse
Affiliation(s)
- Ying-Jung Lai
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Archana Pannuri
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Christine Pourciau
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| |
Collapse
|
14
|
Shimizu K, Matsuoka Y. Feedback regulation and coordination of the main metabolism for bacterial growth and metabolic engineering for amino acid fermentation. Biotechnol Adv 2021; 55:107887. [PMID: 34921951 DOI: 10.1016/j.biotechadv.2021.107887] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 12/05/2021] [Accepted: 12/09/2021] [Indexed: 12/28/2022]
Abstract
Living organisms such as bacteria are often exposed to continuous changes in the nutrient availability in nature. Therefore, bacteria must constantly monitor the environmental condition, and adjust the metabolism quickly adapting to the change in the growth condition. For this, bacteria must orchestrate (coordinate and integrate) the complex and dynamically changing information on the environmental condition. In particular, the central carbon metabolism (CCM), monomer synthesis, and macromolecular synthesis must be coordinately regulated for the efficient growth. It is a grand challenge in bioscience, biotechnology, and synthetic biology to understand how living organisms coordinate the metabolic regulation systems. Here, we consider the integrated sensing of carbon sources by the phosphotransferase system (PTS), and the feed-forward/feedback regulation systems incorporated in the CCM in relation to the pool sizes of flux-sensing metabolites and αketoacids. We also consider the metabolic regulation of amino acid biosynthesis (as well as purine and pyrimidine biosyntheses) paying attention to the feedback control systems consisting of (fast) enzyme level regulation with (slow) transcriptional regulation. The metabolic engineering for the efficient amino acid production by bacteria such as Escherichia coli and Corynebacterium glutamicum is also discussed (in relation to the regulation mechanisms). The amino acid synthesis is important for determining the rate of ribosome biosynthesis. Thus, the growth rate control (growth law) is further discussed on the relationship between (p)ppGpp level and the ribosomal protein synthesis.
Collapse
Affiliation(s)
- Kazuyuki Shimizu
- Kyushu institute of Technology, Iizuka, Fukuoka 820-8502, Japan; Institute of Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0017, Japan.
| | - Yu Matsuoka
- Department of Fisheries Distribution and Management, National Fisheries University, Shimonoseki, Yamaguchi 759-6595, Japan
| |
Collapse
|
15
|
López-Pliego L, Lara-Flores N, Molina-Romero D, May-Compañ G, Carreño-López R, Núñez CE, Castañeda M. The GacS/A-Rsm Pathway Positively Regulates Motility and Flagella Synthesis in Azotobacter vinelandii. Curr Microbiol 2021; 79:17. [PMID: 34905080 DOI: 10.1007/s00284-021-02695-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 10/21/2021] [Indexed: 10/19/2022]
Abstract
Azotobacter vinelandii is a motile bacterium that possesses an unusual pattern of peritrichous flagellation for members of the Pseudomonadaceae family. Unlike what has been reported for Pseudomonas spp. FleQ is not the master regulator of motility in A. vinelandii, this role is performed by FlhDC. Other factors involved in the regulation of motility are AlgU (σE) and CydR which act as negative regulators. In some members of the Enterobacteriaceae and Pseudomonadaceae families, the GacS/A-Rsm pathway is another important factor regulating motility. In the present study, the involvement of the GacS/A-Rsm pathway in regulating the motility of A. vinelandii was explored; we found that contrary to what has been reported for most of the strains studied of Pseudomonas species, GacS/A, through the Rsm system, positively controlled swimming motility. We show that the target of this regulation is the synthesis of flagella, which most likely occurs in an FlhDC-independent manner.
Collapse
Affiliation(s)
- Liliana López-Pliego
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, IC-11 Ciudad Universitaria, Apdo, Postal 1622, C. P. 72000, Puebla, Pue, México
| | - Norarizbeth Lara-Flores
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, IC-11 Ciudad Universitaria, Apdo, Postal 1622, C. P. 72000, Puebla, Pue, México.,Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, 13 Sur 2702, C. P. 72410, Puebla, Pue, México
| | - Dalia Molina-Romero
- Facultad de Ciencias Biológicas, BIO-1 Ciudad Universitaria, C. P. 72000, Puebla, Pue, México
| | - Gabriela May-Compañ
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, IC-11 Ciudad Universitaria, Apdo, Postal 1622, C. P. 72000, Puebla, Pue, México.,Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, 13 Sur 2702, C. P. 72410, Puebla, Pue, México
| | - Ricardo Carreño-López
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, IC-11 Ciudad Universitaria, Apdo, Postal 1622, C. P. 72000, Puebla, Pue, México
| | - Cinthia E Núñez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, C. P. 62250, Cuernavaca, Mor, México
| | - Miguel Castañeda
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, IC-11 Ciudad Universitaria, Apdo, Postal 1622, C. P. 72000, Puebla, Pue, México.
| |
Collapse
|
16
|
Liu G, Chang H, Qiao Y, Huang K, Zhang A, Zhao Y, Feng Z. Profiles of Small Regulatory RNAs at Different Growth Phases of Streptococcus thermophilus During pH-Controlled Batch Fermentation. Front Microbiol 2021; 12:765144. [PMID: 35035386 PMCID: PMC8753986 DOI: 10.3389/fmicb.2021.765144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/05/2021] [Indexed: 12/02/2022] Open
Abstract
Small regulatory RNA (sRNA) has been shown to play an important role under various stress conditions in bacteria, and it plays a vital role in regulating growth, adaptation and survival through posttranscriptional control of gene expression in bacterial cells. Streptococcus thermophilus is widely used as a starter culture in the manufacture of fermented dairy products. However, the lack of reliable information on the expression profiles and potential physiological functions of sRNAs in this species hinders our understanding of the importance of sRNAs in S. thermophilus. The present study was conducted to assess the expression profiles of sRNAs in S. thermophilus and to identify sRNAs that exhibited significant changes. A total of 530 potential sRNAs were identified, including 198 asRNAs, 135 sRNAs from intergenic regions, and 197 sRNAs from untranslated regions (UTRs). Significant changes occurred in the expression of 238, 83, 194, and 139 sRNA genes during the lag, early exponential growth, late exponential growth, and stationary phases, respectively. The expression of 14 of the identified sRNAs was verified by qRT-PCR. Predictions of the target genes of these candidate sRNAs showed that the primary metabolic pathways targeted were involved in carbon metabolism, biosynthesis of amino acids, ABC transporters, the metabolism of amino and nucleotide sugars, purine metabolism, and the phosphotransferase system. The expression of the predicted target genes was further analyzed to better understand the roles of sRNAs during different growth stages. The results suggested that these sRNAs play crucial roles by regulating biological pathways during different growth phases of S. thermophilus. According to the results, sRNAs sts141, sts392, sts318, and sts014 are involved in the regulation of osmotic stress. sRNAs sts508, sts087, sts372, sts141, sts375, and sts119 are involved in the regulation of starvation stress. sRNAs sts129, sts226, sts166, sts231, sts204, sts145, and sts236 are involved in arginine synthesis. sRNAs sts033, sts341, sts492, sts140, sts230, sts172, and sts377 are involved in the ADI pathway. The present study provided valuable information for the functional study of sRNAs in S. thermophilus and indicated a future research direction for sRNA in S. thermophilus. Overall, our results provided new insights for understanding the complex regulatory network of sRNAs in S. thermophilus.
Collapse
Affiliation(s)
- Gefei Liu
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Haode Chang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Yali Qiao
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Kai Huang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Ao Zhang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Yu Zhao
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning, 571533, Hainan, China
- Yu Zhao,
| | - Zhen Feng
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
- College of Food and Biological Engineering, Qiqihar University, 42 Wenhua Road, 160006, Qiqihar, China
- *Correspondence: Zhen Feng,
| |
Collapse
|
17
|
Alvarez AF, Rodríguez C, González-Chávez R, Georgellis D. The Escherichia coli two-component signal sensor BarA binds protonated acetate via a conserved hydrophobic-binding pocket. J Biol Chem 2021; 297:101383. [PMID: 34743001 PMCID: PMC8639471 DOI: 10.1016/j.jbc.2021.101383] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 11/11/2022] Open
Abstract
The BarA/UvrY two-component signal transduction system is widely conserved in γ-proteobacteria and provides a link between the metabolic state of the cells and the Csr posttranscriptional regulatory system. In Escherichia coli, the BarA/UvrY system responds to the presence of acetate and other short-chain carboxylic acids by activating transcription of the noncoding RNAs, CsrB and CsrC, which sequester the RNA-binding protein CsrA, a global regulator of gene expression. However, the state of the carboxyl group in the acetate molecule, which serves as the BarA stimulus, and the signal reception site of BarA remain unknown. In this study, we show that the deletion or replacement of the periplasmic domain of BarA and also the substitution of certain hydroxylated and hydrophobic amino acid residues in this region, result in a sensor kinase that remains unresponsive to its physiological stimulus, demonstrating that the periplasmic region of BarA constitutes a functional detector domain. Moreover, we provide evidence that the protonated state of acetate or formate serves as the physiological stimulus of BarA. In addition, modeling of the BarA sensor domain and prediction of the signal-binding site, by blind molecular docking, revealed a calcium channels and chemotaxis receptors domain with a conserved binding pocket, which comprised uncharged polar and hydrophobic amino acid residues. Based on the comparative sequence and phylogenetic analyses, we propose that, at least, two types of BarA orthologues diverged and evolved separately to acquire distinct signal-binding properties, illustrating the wide adaptability of the bacterial sensor kinase proteins.
Collapse
Affiliation(s)
- Adrián F Alvarez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| | - Claudia Rodríguez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| | - Ricardo González-Chávez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| | - Dimitris Georgellis
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México.
| |
Collapse
|
18
|
Ferreiro MD, Behrmann LV, Corral A, Nogales J, Gallegos MT. Exploring the expression and functionality of the rsm sRNAs in Pseudomonas syringae pv. tomato DC3000. RNA Biol 2021; 18:1818-1833. [PMID: 33406981 PMCID: PMC8583166 DOI: 10.1080/15476286.2020.1871217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/08/2020] [Accepted: 12/29/2020] [Indexed: 12/18/2022] Open
Abstract
The Gac-rsm pathway is a global regulatory network that governs mayor lifestyle and metabolic changes in gamma-proteobacteria. In a previous study, we uncovered the role of CsrA proteins promoting growth and repressing motility, alginate production and virulence in the model phytopathogen Pseudomonas syringae pv. tomato (Pto) DC3000. Here, we focus on the expression and regulation of the rsm regulatory sRNAs, since Pto DC3000 exceptionally has seven variants (rsmX1-5, rsmY and rsmZ). The presented results offer further insights into the functioning of the complex Gac-rsm pathway and the interplay among its components. Overall, rsm expressions reach maximum levels at high cell densities, are unaffected by surface detection, and require GacA for full expression. The rsm levels of expression and GacA-dependence are determined by the sequences found in their -35/-10 promoter regions and GacA binding boxes, respectively. rsmX5 stands out for being the only rsm in Pto DC3000 whose high expression does not require GacA, constituting the main component of the total rsm pool in a gacA mutant. The deletion of rsmY and rsmZ had minor effects on Pto DC3000 motility and virulence phenotypes, indicating that rsmX1-5 can functionally replace them. On the other hand, rsmY or rsmZ overexpression in a gacA mutant did not revert its phenotype. Additionally, a negative feedback regulatory loop in which the CsrA3 protein promotes its own titration by increasing the levels of several rsm RNAs in a GacA-dependent manner has been disclosed as part of this work.
Collapse
Affiliation(s)
- María-Dolores Ferreiro
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental Del Zaidín (EEZ-CSIC), Granada, Spain
| | - Lara Vanessa Behrmann
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental Del Zaidín (EEZ-CSIC), Granada, Spain
| | - Ana Corral
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental Del Zaidín (EEZ-CSIC), Granada, Spain
| | - Joaquina Nogales
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental Del Zaidín (EEZ-CSIC), Granada, Spain
| | - María-Trinidad Gallegos
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental Del Zaidín (EEZ-CSIC), Granada, Spain
| |
Collapse
|
19
|
Lucas-Elío P, Molina-Quintero LR, Xu H, Sánchez-Amat A. A histidine kinase and a response regulator provide phage resistance to Marinomonas mediterranea via CRISPR-Cas regulation. Sci Rep 2021; 11:20564. [PMID: 34663886 PMCID: PMC8523701 DOI: 10.1038/s41598-021-99740-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 09/24/2021] [Indexed: 11/09/2022] Open
Abstract
CRISPR-Cas systems are used by many prokaryotes to defend against invading genetic elements. In many cases, more than one CRISPR-Cas system co-exist in the same cell. Marinomonas mediterranea MMB-1 possesses two CRISPR-Cas systems, of type I-F and III-B respectively, which collaborate in phage resistance raising questions on how their expression is regulated. This study shows that the expression of both systems is controlled by the histidine kinase PpoS and a response regulator, PpoR, identified and cloned in this study. These proteins show similarity to the global regulators BarA/UvrY. In addition, homologues to the sRNAs CsrB and CsrC and the gene coding for the post-transcriptional repressor CsrA have been also identified indicating the conservation of the elements of the BarA/UvrY regulatory cascade in M. mediterranea. RNA-Seq analyses have revealed that all these genetics elements are regulated by PpoS/R supporting their participation in the regulatory cascade. The regulation by PpoS and PpoR of the CRISPR-Cas systems plays a role in phage defense since mutants in these proteins show an increase in phage sensitivity.
Collapse
Affiliation(s)
- Patricia Lucas-Elío
- Department of Genetics and Microbiology, University of Murcia, 30100, Murcia, Spain
| | | | - Hengyi Xu
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA
| | - Antonio Sánchez-Amat
- Department of Genetics and Microbiology, University of Murcia, 30100, Murcia, Spain.
| |
Collapse
|
20
|
Abstract
Mg2+ is the most abundant divalent cation in living cells. It is essential for charge neutralization, macromolecule stabilization, and the assembly and activity of ribosomes and as a cofactor for enzymatic reactions. When experiencing low cytoplasmic Mg2+, bacteria adopt two main strategies: They increase the abundance and activity of Mg2+ importers and decrease the abundance of Mg2+-chelating ATP and rRNA. These changes reduce regulated proteolysis by ATP-dependent proteases and protein synthesis in a systemic fashion. In many bacterial species, the transcriptional regulator PhoP controls expression of proteins mediating these changes. The 5' leader region of some mRNAs responds to low cytoplasmic Mg2+ or to disruptions in translation of open reading frames in the leader regions by furthering expression of the associated coding regions, which specify proteins mediating survival when the cytoplasmic Mg2+ concentration is low. Microbial species often utilize similar adaptation strategies to cope with low cytoplasmic Mg2+ despite relying on different genes to do so.
Collapse
Affiliation(s)
- Eduardo A Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, USA; .,Yale Microbial Sciences Institute, West Haven, Connecticut 06516, USA
| | - Carissa Chan
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, USA;
| |
Collapse
|
21
|
Campa AR, Smith LM, Hampton HG, Sharma S, Jackson SA, Bischler T, Sharma CM, Fineran PC. The Rsm (Csr) post-transcriptional regulatory pathway coordinately controls multiple CRISPR-Cas immune systems. Nucleic Acids Res 2021; 49:9508-9525. [PMID: 34403463 PMCID: PMC8450108 DOI: 10.1093/nar/gkab704] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 12/15/2022] Open
Abstract
CRISPR-Cas systems provide bacteria with adaptive immunity against phages and plasmids; however, pathways regulating their activity are not well defined. We recently developed a high-throughput genome-wide method (SorTn-seq) and used this to uncover CRISPR-Cas regulators. Here, we demonstrate that the widespread Rsm/Csr pathway regulates the expression of multiple CRISPR-Cas systems in Serratia (type I-E, I-F and III-A). The main pathway component, RsmA (CsrA), is an RNA-binding post-transcriptional regulator of carbon utilisation, virulence and motility. RsmA binds cas mRNAs and suppresses type I and III CRISPR-Cas interference in addition to adaptation by type I systems. Coregulation of CRISPR-Cas and flagella by the Rsm pathway allows modulation of adaptive immunity when changes in receptor availability would alter susceptibility to flagella-tropic phages. Furthermore, we show that Rsm controls CRISPR-Cas in other genera, suggesting conservation of this regulatory strategy. Finally, we identify genes encoding RsmA homologues in phages, which have the potential to manipulate the physiology of host bacteria and might provide an anti-CRISPR activity.
Collapse
Affiliation(s)
- Aroa Rey Campa
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.,Bio-Protection Research Centre, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Leah M Smith
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Hannah G Hampton
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Sahil Sharma
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Simon A Jackson
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.,Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Thorsten Bischler
- Core Unit Systems Medicine, University of Würzburg, 97080 Würzburg, Germany
| | - Cynthia M Sharma
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.,Bio-Protection Research Centre, University of Otago, PO Box 56, Dunedin 9054, New Zealand.,Genetics Otago, University of Otago, Dunedin, New Zealand
| |
Collapse
|
22
|
Groisman EA, Duprey A, Choi J. How the PhoP/PhoQ System Controls Virulence and Mg 2+ Homeostasis: Lessons in Signal Transduction, Pathogenesis, Physiology, and Evolution. Microbiol Mol Biol Rev 2021; 85:e0017620. [PMID: 34191587 PMCID: PMC8483708 DOI: 10.1128/mmbr.00176-20] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The PhoP/PhoQ two-component system governs virulence, Mg2+ homeostasis, and resistance to a variety of antimicrobial agents, including acidic pH and cationic antimicrobial peptides, in several Gram-negative bacterial species. Best understood in Salmonella enterica serovar Typhimurium, the PhoP/PhoQ system consists o-regulated gene products alter PhoP-P amounts, even under constant inducing conditions. PhoP-P controls the abundance of hundreds of proteins both directly, by having transcriptional effects on the corresponding genes, and indirectly, by modifying the abundance, activity, or stability of other transcription factors, regulatory RNAs, protease regulators, and metabolites. The investigation of PhoP/PhoQ has uncovered novel forms of signal transduction and the physiological consequences of regulon evolution.
Collapse
Affiliation(s)
- Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Microbial Sciences Institute, West Haven, Connecticut, USA
| | - Alexandre Duprey
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jeongjoon Choi
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| |
Collapse
|
23
|
Mihailovic MK, Ekdahl AM, Chen A, Leistra AN, Li B, González Martínez J, Law M, Ejindu C, Massé É, Freddolino PL, Contreras LM. Uncovering Transcriptional Regulators and Targets of sRNAs Using an Integrative Data-Mining Approach: H-NS-Regulated RseX as a Case Study. Front Cell Infect Microbiol 2021; 11:696533. [PMID: 34327153 PMCID: PMC8313858 DOI: 10.3389/fcimb.2021.696533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial small RNAs (sRNAs) play a vital role in pathogenesis by enabling rapid, efficient networks of gene attenuation during infection. In recent decades, there has been a surge in the number of proposed and biochemically-confirmed sRNAs in both Gram-positive and Gram-negative pathogens. However, limited homology, network complexity, and condition specificity of sRNA has stunted complete characterization of the activity and regulation of these RNA regulators. To streamline the discovery of the expression of sRNAs, and their post-transcriptional activities, we propose an integrative in vivo data-mining approach that couples DNA protein occupancy, RNA-seq, and RNA accessibility data with motif identification and target prediction algorithms. We benchmark the approach against a subset of well-characterized E. coli sRNAs for which a degree of in vivo transcriptional regulation and post-transcriptional activity has been previously reported, finding support for known regulation in a large proportion of this sRNA set. We showcase the abilities of our method to expand understanding of sRNA RseX, a known envelope stress-linked sRNA for which a cellular role has been elusive due to a lack of native expression detection. Using the presented approach, we identify a small set of putative RseX regulators and targets for experimental investigation. These findings have allowed us to confirm native RseX expression under conditions that eliminate H-NS repression as well as uncover a post-transcriptional role of RseX in fimbrial regulation. Beyond RseX, we uncover 163 putative regulatory DNA-binding protein sites, corresponding to regulation of 62 sRNAs, that could lead to new understanding of sRNA transcription regulation. For 32 sRNAs, we also propose a subset of top targets filtered by engagement of regions that exhibit binding site accessibility behavior in vivo. We broadly anticipate that the proposed approach will be useful for sRNA-reliant network characterization in bacteria. Such investigations under pathogenesis-relevant environmental conditions will enable us to deduce complex rapid-regulation schemes that support infection.
Collapse
Affiliation(s)
- Mia K Mihailovic
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Alyssa M Ekdahl
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Angela Chen
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Abigail N Leistra
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Bridget Li
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Javier González Martínez
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Matthew Law
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Cindy Ejindu
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Éric Massé
- Department of Biochemistry and Functional Genomics, Universitéde Sherbrooke, RNA Group, Sherbrooke, QC, Canada
| | - Peter L Freddolino
- Department of Biological Chemistry and Department of Computational Medicine & Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| |
Collapse
|
24
|
Shimada T, Ogasawara H, Kobayashi I, Kobayashi N, Ishihama A. Single-Target Regulators Constitute the Minority Group of Transcription Factors in Escherichia coli K-12. Front Microbiol 2021; 12:697803. [PMID: 34220787 PMCID: PMC8249747 DOI: 10.3389/fmicb.2021.697803] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 05/28/2021] [Indexed: 11/13/2022] Open
Abstract
The identification of regulatory targets of all transcription factors (TFs) is critical for understanding the entire network of genome regulation. A total of approximately 300 TFs exist in the model prokaryote Escherichia coli K-12, but the identification of whole sets of their direct targets is impossible with use of in vivo approaches. For this end, the most direct and quick approach is to identify the TF-binding sites in vitro on the genome. We then developed and utilized the gSELEX screening system in vitro for identification of more than 150 E. coli TF-binding sites along the E. coli genome. Based on the number of predicted regulatory targets, we classified E. coli K-12 TFs into four groups, altogether forming a hierarchy ranging from a single-target TF (ST-TF) to local TFs, global TFs, and nucleoid-associated TFs controlling as many as 1,000 targets. Using the collection of purified TFs and a library of genome DNA segments from a single and the same E. coli K-12, we identified here a total of 11 novel ST-TFs, CsqR, CusR, HprR, NorR, PepA, PutA, QseA, RspR, UvrY, ZraR, and YqhC. The regulation of single-target promoters was analyzed in details for the hitherto uncharacterized QseA and RspR. In most cases, the ST-TF gene and its regulatory target genes are adjacently located on the E. coli K-12 genome, implying their simultaneous transfer in the course of genome evolution. The newly identified 11 ST-TFs and the total of 13 hitherto identified altogether constitute the minority group of TFs in E. coli K-12.
Collapse
Affiliation(s)
| | - Hiroshi Ogasawara
- Research Center for Supports to Advanced Science, Division of Gene Research, Shinshu University, Nagano, Japan.,Research Center for Fungal and Microbial Dynamism, Shinshu University, Nagano, Japan
| | - Ikki Kobayashi
- School of Agriculture, Meiji University, Kawasaki, Japan
| | - Naoki Kobayashi
- Department of Frontier Science, Hosei University, Koganei, Japan
| | - Akira Ishihama
- Department of Frontier Science, Hosei University, Koganei, Japan.,Micro-Nano Technology Research Center, Hosei University, Koganei, Japan
| |
Collapse
|
25
|
de Pina LC, da Silva FSH, Galvão TC, Pauer H, Ferreira RBR, Antunes LCM. The role of two-component regulatory systems in environmental sensing and virulence in Salmonella. Crit Rev Microbiol 2021; 47:397-434. [PMID: 33751923 DOI: 10.1080/1040841x.2021.1895067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Adaptation to environments with constant fluctuations imposes challenges that are only overcome with sophisticated strategies that allow bacteria to perceive environmental conditions and develop an appropriate response. The gastrointestinal environment is a complex ecosystem that is home to trillions of microorganisms. Termed microbiota, this microbial ensemble plays important roles in host health and provides colonization resistance against pathogens, although pathogens have evolved strategies to circumvent this barrier. Among the strategies used by bacteria to monitor their environment, one of the most important are the sensing and signalling machineries of two-component systems (TCSs), which play relevant roles in the behaviour of all bacteria. Salmonella enterica is no exception, and here we present our current understanding of how this important human pathogen uses TCSs as an integral part of its lifestyle. We describe important aspects of these systems, such as the stimuli and responses involved, the processes regulated, and their roles in virulence. We also dissect the genomic organization of histidine kinases and response regulators, as well as the input and output domains for each TCS. Lastly, we explore how these systems may be promising targets for the development of antivirulence therapeutics to combat antibiotic-resistant infections.
Collapse
Affiliation(s)
- Lucindo Cardoso de Pina
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Biociências, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.,Programa de Pós-Graduação Ciência para o Desenvolvimento, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | | | - Teca Calcagno Galvão
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Heidi Pauer
- Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças de Populações Negligenciadas, Rio de Janeiro, Brazil
| | | | - L Caetano M Antunes
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças de Populações Negligenciadas, Rio de Janeiro, Brazil.,Laboratório de Pesquisa em Infecção Hospitalar, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| |
Collapse
|
26
|
Chen YW, Yeh WH, Tang HJ, Chen JW, Shu HY, Su YC, Wang ST, Kuo CJ, Chuang YC, Chen CC, Ko WC, Chen CS, Chen PL. UvrY is required for the full virulence of Aeromonas dhakensis. Virulence 2021; 11:502-520. [PMID: 32434424 PMCID: PMC7250320 DOI: 10.1080/21505594.2020.1768339] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Aeromonas dhakensis is an emerging human pathogen which causes fast and severe infections worldwide. Under the gradual pressure of lacking useful antibiotics, finding a new strategy against A. dhakensis infection is urgent. To understand its pathogenesis, we created an A. dhakensis AAK1 mini-Tn10 transposon library to study the mechanism of A. dhakensis infection. By using a Caenorhabditis elegans model, we established a screening platform for the purpose of identifying attenuated mutants. The uvrY mutant, which conferred the most attenuated toxicity toward C. elegans, was identified. The uvrY mutant was also less virulent in C2C12 fibroblast and mice models, in line with in vitro results. To further elucidate the mechanism of UvrY in controlling the toxicity in A. dhakensis, we conducted a transcriptomic analysis. The RNAseq results showed that the expression of a unique hemolysin ahh1 and other virulence factors were regulated by UvrY. Complementation of Ahh1, one of the most important virulence factors, rescued the pore-formation phenotype of uvrY mutant in C. elegans; however, complementation of ahh1 endogenous promoter-driven ahh1 could not produce Ahh1 and rescue the virulence in the uvrY mutant. These findings suggest that UvrY is required for the expression of Ahh1 in A. dhakensis. Taken together, our results suggested that UvrY controls several different virulence factors and is required for the full virulence of A. dhakensis. The two-component regulator UvrY therefore a potential therapeutic target which is worthy of further study.
Collapse
Affiliation(s)
- Yi-Wei Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, CA, USA
| | - Wen-Hsuan Yeh
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hung-Jen Tang
- Department of Medicine, Chi Mei Medical Center, Tainan, Taiwan
| | - Jenn-Wei Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hung-Yu Shu
- Department of Bioscience Technology, Chang Jung Christian University, Tainan, Taiwan
| | - Yu-Chen Su
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Sin-Tian Wang
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Cheng-Ju Kuo
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yin-Ching Chuang
- Department of Medicine, Chi Mei Medical Center, Tainan, Taiwan.,Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan
| | - Chi-Chung Chen
- Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan.,Department of Food Science, National Chiayi University, Chiayi, Taiwan
| | - Wen-Chien Ko
- Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chang-Shi Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Po-Lin Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
27
|
Genome-wide Identification of DNA-protein Interaction to Reconstruct Bacterial Transcription Regulatory Network. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-020-0030-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
28
|
Contact with the CsrA Core Is Required for Allosteric Inhibition by FliW in Bacillus subtilis. J Bacteriol 2020; 203:JB.00574-20. [PMID: 33106347 DOI: 10.1128/jb.00574-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 11/20/2022] Open
Abstract
The RNA-binding protein CsrA is a posttranscriptional regulator encoded by genomes throughout the bacterial phylogeny. In the gammaproteobacteria, the activity of CsrA is inhibited by small RNAs that competitively sequester CsrA binding. In contrast, the firmicute Bacillus subtilis encodes a protein inhibitor of CsrA called FliW, which noncompetitively inhibits CsrA activity but for which the precise mechanism of antagonism is unclear. Here, we take an unbiased genetic approach to identify residues of FliW important for CsrA inhibition and these residues fall into two distinct spatial and functional classes. Most loss-of-function alleles mutated FliW residues surrounding the critical regulatory CsrA residue N55 and abolished interaction between the two proteins. Two loss-of-function alleles, however, mutated FliW residues near the CsrA core dimerization domain and maintained interaction with CsrA. One of the FliW alleles reversed a residue charge to disrupt a salt bridge with the CsrA core, and a compensatory charge reversal in the CsrA partner residue restored both the salt bridge and antagonism. We propose a model in which the initial interaction between FliW and CsrA is necessary but not sufficient for antagonism, and for which salt bridge formation with, and deformation of, the CsrA core domain is likely required to allosterically abolish RNA-binding activity.IMPORTANCE CsrA is a small dimeric protein that binds RNA and is one of the few known examples of transcript-specific protein regulators of translation in bacteria. A protein called FliW binds to and antagonizes CsrA to govern flagellin homeostasis and flagellar assembly. Despite having a high-resolution three-dimensional structure of the FliW-CsrA complex, the mechanism of noncompetitive inhibition remains unresolved. Here, we identify FliW residues required for antagonism and we find that the residues make a linear connection in the complex from initial binding interaction with CsrA to a critical salt bridge near the core of the CsrA dimer. We propose that the salt bridge represents an allosteric contact that distorts the CsrA core to prevent RNA binding.
Collapse
|
29
|
El Mouali Y, Esteva-Martínez G, García-Pedemonte D, Balsalobre C. Differential Regulation of CsrC and CsrB by CRP-cAMP in Salmonella enterica. Front Microbiol 2020; 11:570536. [PMID: 33162952 PMCID: PMC7591399 DOI: 10.3389/fmicb.2020.570536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/17/2020] [Indexed: 12/02/2022] Open
Abstract
Post-transcriptional regulation mediated by regulatory small RNAs (sRNAs) has risen as a key player in fine-tuning gene expression in response to environmental stimuli. Here, we show that, in Salmonella enterica, the central metabolic regulator CRP-cAMP differentially regulates the sRNAs CsrB and CsrC in a growth phase-dependent manner. While CsrB expression remains unchanged during growth, CsrC displays a growth phase-dependent expression profile, being weakly expressed at the logarithmic growth phase and induced upon entry into stationary phase. We show that CRP-cAMP contributes to the expression pattern of CsrC by repressing its expression during the logarithmic growth phase. The CRP-cAMP mediated repression of CsrC is independent of SirA, a known transcriptional CsrB/CsrC activator. We further show that the sRNA Spot 42, which is derepressed in a Δcrp strain, upregulates CsrC during logarithmic growth. We propose a model where the growth-dependent regulation of CsrC is sustained by the CRP-cAMP-mediated repression of Spot 42. Together, our data point toward a differential regulation of the sRNAs CsrB and CsrC in response to environmental stimuli, leading to fine-tuning of gene expression via the sequestration of the RNA-binding protein CsrA.
Collapse
Affiliation(s)
- Youssef El Mouali
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Guillem Esteva-Martínez
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Barcelona, Spain
| | - David García-Pedemonte
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Carlos Balsalobre
- Department of Genetics, Microbiology and Statistics, School of Biology, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
30
|
Pourciau C, Lai YJ, Gorelik M, Babitzke P, Romeo T. Diverse Mechanisms and Circuitry for Global Regulation by the RNA-Binding Protein CsrA. Front Microbiol 2020; 11:601352. [PMID: 33193284 PMCID: PMC7652899 DOI: 10.3389/fmicb.2020.601352] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
The carbon storage regulator (Csr) or repressor of stationary phase metabolites (Rsm) system of Gammaproteobacteria is among the most complex and best-studied posttranscriptional regulatory systems. Based on a small RNA-binding protein, CsrA and homologs, it controls metabolism, physiology, and bacterial lifestyle decisions by regulating gene expression on a vast scale. Binding of CsrA to sequences containing conserved GGA motifs in mRNAs can regulate translation, RNA stability, riboswitch function, and transcript elongation. CsrA governs the expression of dozens of transcription factors and other regulators, further expanding its influence on cellular physiology, and these factors can participate in feedback to the Csr system. Expression of csrA itself is subject to autoregulation via translational inhibition and indirect transcriptional activation. CsrA activity is controlled by small noncoding RNAs (sRNAs), CsrB and CsrC in Escherichia coli, which contain multiple high affinity CsrA binding sites that compete with those of mRNA targets. Transcription of CsrB/C is induced by certain nutrient limitations, cellular stresses, and metabolites, while these RNAs are targeted for degradation by the presence of a preferred carbon source. Consistent with these findings, CsrA tends to activate pathways and processes that are associated with robust growth and repress stationary phase metabolism and stress responses. Regulatory loops between Csr components affect the signaling dynamics of the Csr system. Recently, systems-based approaches have greatly expanded our understanding of the roles played by CsrA, while reinforcing the notion that much remains to be learned about the Csr system.
Collapse
Affiliation(s)
- Christine Pourciau
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Ying-Jung Lai
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Mark Gorelik
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, United States
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| |
Collapse
|
31
|
Piattelli E, Peltier J, Soutourina O. Interplay between Regulatory RNAs and Signal Transduction Systems during Bacterial Infection. Genes (Basel) 2020; 11:E1209. [PMID: 33081172 PMCID: PMC7602753 DOI: 10.3390/genes11101209] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 12/13/2022] Open
Abstract
The ability of pathogenic bacteria to stably infect the host depends on their capacity to respond and adapt to the host environment and on the efficiency of their defensive mechanisms. Bacterial envelope provides a physical barrier protecting against environmental threats. It also constitutes an important sensory interface where numerous sensing systems are located. Signal transduction systems include Two-Component Systems (TCSs) and alternative sigma factors. These systems are able to sense and respond to the ever-changing environment inside the host, altering the bacterial transcriptome to mitigate the impact of the stress. The regulatory networks associated with signal transduction systems comprise small regulatory RNAs (sRNAs) that can be directly involved in the expression of virulence factors. The aim of this review is to describe the importance of TCS- and alternative sigma factor-associated sRNAs in human pathogens during infection. The currently available genome-wide approaches for studies of TCS-regulated sRNAs will be discussed. The differences in the signal transduction mediated by TCSs between bacteria and higher eukaryotes and the specificity of regulatory RNAs for their targets make them appealing targets for discovery of new strategies to fight against multi-resistant bacteria.
Collapse
Affiliation(s)
- Emma Piattelli
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (E.P.); (J.P.)
| | - Johann Peltier
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (E.P.); (J.P.)
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, 75015 Paris, France
| | - Olga Soutourina
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (E.P.); (J.P.)
- Institut Universitaire de France, CEDEX 05, 75231 Paris, France
| |
Collapse
|
32
|
Abstract
The Csr system of E. coli controls gene expression and physiology on a global scale. CsrA protein, the central component of this system, represses translation initiation of numerous genes by binding to target transcripts, thereby competing with ribosome binding. Variations of this mechanism are so common that CsrA is sometimes called a translational repressor. Although CsrA-mediated activation mechanisms have been elucidated in which bound CsrA inhibits RNA degradation, no translation activation mechanism has been defined. Here, we demonstrate that CsrA binding to two sites in the 5′ untranslated leader of ymdA mRNA activates translation by destabilizing a structure that otherwise prevents ribosome binding. The extensive role of CsrA in activating gene expression suggests the common occurrence of similar activation mechanisms. The sequence-specific RNA-binding protein CsrA is the central component of the conserved global regulatory Csr system. In Escherichia coli, CsrA regulates many cellular processes, including biofilm formation, motility, carbon metabolism, iron homeostasis, and stress responses. Such regulation often involves translational repression by CsrA binding to an mRNA target, thereby inhibiting ribosome binding. While CsrA also extensively activates gene expression, no detailed mechanism for CsrA-mediated translational activation has been demonstrated. An integrated transcriptomic study identified ymdA as having the strongest CsrA-mediated activation across the E. coli transcriptome. Here, we determined that CsrA activates ymdA expression posttranscriptionally. Gel mobility shift, footprint, toeprint, and in vitro coupled transcription-translation assays identified two CsrA binding sites in the leader region of the ymdA transcript that are critical for translational activation. Reporter fusion assays confirmed that CsrA activates ymdA expression at the posttranscriptional level in vivo. Furthermore, loss of binding at either of the two CsrA binding sites abolished CsrA-dependent activation. mRNA half-life studies revealed that CsrA also contributes to stabilization of ymdA mRNA. RNA structure prediction revealed an RNA hairpin upstream of the ymdA start codon that sequesters the Shine-Dalgarno (SD) sequence, which would inhibit ribosome binding. This hairpin also contains one of the two critical CsrA binding sites, with the other site located just upstream. Our results demonstrate that bound CsrA destabilizes the SD-sequestering hairpin such that the ribosome can bind and initiate translation. Since YmdA represses biofilm formation, CsrA-mediated activation of ymdA expression may repress biofilm formation under certain conditions.
Collapse
|
33
|
Sobrero PM, Valverde C. Comparative Genomics and Evolutionary Analysis of RNA-Binding Proteins of the CsrA Family in the Genus Pseudomonas. Front Mol Biosci 2020; 7:127. [PMID: 32754614 PMCID: PMC7366521 DOI: 10.3389/fmolb.2020.00127] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022] Open
Abstract
Gene expression is adjusted according to cellular needs through a combination of mechanisms acting at different layers of the flow of genetic information. At the posttranscriptional level, RNA-binding proteins are key factors controlling the fate of nascent and mature mRNAs. Among them, the members of the CsrA family are small dimeric proteins with heterogeneous distribution across the bacterial tree of life, that act as global regulators of gene expression because they recognize characteristic sequence/structural motifs (short hairpins with GGA triplets in the loop) present in hundreds of mRNAs. The regulatory output of CsrA binding to mRNAs is counteracted in most cases by molecular mimic, non-protein coding RNAs that titrate the CsrA dimers away from the target mRNAs. In γ-proteobacteria, the regulatory modules composed by CsrA homologs and the corresponding antagonistic sRNAs, are mastered by two-component systems of the GacS-GacA type, which control the transcription and the abundance of the sRNAs, thus constituting the rather linear cascade Gac-Rsm that responds to environmental or cellular signals to adjust and coordinate the expression of a set of target genes posttranscriptionally. Within the γ-proteobacteria, the genus Pseudomonas has been shown to contain species with different number of active CsrA (RsmA) homologs and of molecular mimic sRNAs. Here, with the help of the increasing availability of genomic data we provide a comprehensive state-of-the-art picture of the remarkable multiplicity of CsrA lineages, including novel yet uncharacterized paralogues, and discuss evolutionary aspects of the CsrA subfamilies of the genus Pseudomonas, and implications of the striking presence of csrA alleles in natural mobile genetic elements (phages and plasmids).
Collapse
Affiliation(s)
- Patricio Martín Sobrero
- Laboratorio de Fisiología y Genética de Bacterias Beneficiosas para Plantas, Centro de Bioquímica y Microbiología del Suelo, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes - CONICET, Buenos Aires, Argentina
| | - Claudio Valverde
- Laboratorio de Fisiología y Genética de Bacterias Beneficiosas para Plantas, Centro de Bioquímica y Microbiología del Suelo, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes - CONICET, Buenos Aires, Argentina
| |
Collapse
|
34
|
Hoque MN, Istiaq A, Clement RA, Gibson KM, Saha O, Islam OK, Abir RA, Sultana M, Siddiki AMAMZ, Crandall KA, Hossain MA. Insights Into the Resistome of Bovine Clinical Mastitis Microbiome, a Key Factor in Disease Complication. Front Microbiol 2020; 11:860. [PMID: 32582039 PMCID: PMC7283587 DOI: 10.3389/fmicb.2020.00860] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 04/09/2020] [Indexed: 12/23/2022] Open
Abstract
Bovine clinical mastitis (CM) is one of the most prevalent diseases caused by a wide range of resident microbes. The emergence of antimicrobial resistance in CM bacteria is well-known, however, the genomic resistance composition (the resistome) at the microbiome-level is not well characterized. In this study, we applied whole metagenome sequencing (WMS) to characterize the resistome of the CM microbiome, focusing on antibiotics and metals resistance, biofilm formation (BF), and quorum sensing (QS) along with in vitro resistance assays of six selected pathogens isolated from the same CM samples. The WMS generated an average of 21.13 million reads (post-processing) from 25 CM samples that mapped to 519 bacterial strains, of which 30.06% were previously unreported. We found a significant (P = 0.001) association between the resistomes and microbiome composition with no association with cattle breed, despite significant differences in microbiome diversity among breeds. The in vitro investigation determined that 76.2% of six selected pathogens considered "biofilm formers" actually formed biofilms and were also highly resistant to tetracycline, doxycycline, nalidixic acid, ampicillin, and chloramphenicol and remained sensitive to metals (Cr, Co, Ni, Cu, Zn) at varying concentrations. We also found bacterial flagellar movement and chemotaxis, regulation and cell signaling, and oxidative stress to be significantly associated with the pathophysiology of CM. Thus, identifying CM microbiomes, and analyzing their resistomes and genomic potentials will help improve the optimization of therapeutic schemes involving antibiotics and/or metals usage in the prevention and control of bovine CM.
Collapse
Affiliation(s)
- M. Nazmul Hoque
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
- Department of Gynecology, Obstetrics and Reproductive Health, Faculty of Veterinary Medicine and Animal Science, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - Arif Istiaq
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
- Department of Developmental Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Rebecca A. Clement
- Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, Washington, DC, United States
| | - Keylie M. Gibson
- Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, Washington, DC, United States
| | - Otun Saha
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - Ovinu Kibria Islam
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
- Department of Microbiology, Jashore University of Science and Technology, Jashore, Bangladesh
| | | | - Munawar Sultana
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - AMAM Zonaed Siddiki
- Department of Pathology and Parasitology, Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
| | - Keith A. Crandall
- Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, Washington, DC, United States
- Department of Biostatistics and Bioinformatics, Milken Institute School of Public Health, The George Washington University, Washington, DC, United States
| | - M. Anwar Hossain
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| |
Collapse
|
35
|
Salvail H, Groisman EA. The phosphorelay BarA/SirA activates the non-cognate regulator RcsB in Salmonella enterica. PLoS Genet 2020; 16:e1008722. [PMID: 32392214 PMCID: PMC7241856 DOI: 10.1371/journal.pgen.1008722] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/21/2020] [Accepted: 03/18/2020] [Indexed: 11/18/2022] Open
Abstract
To survive an environmental stress, organisms must detect the stress and mount an appropriate response. One way that bacteria do so is by phosphorelay systems that respond to a stress by activating a regulator that modifies gene expression. To ensure an appropriate response, a given regulator is typically activated solely by its cognate phosphorelay protein(s). However, we now report that the regulator RcsB is activated by both cognate and non-cognate phosphorelay proteins, depending on the condition experienced by the bacterium Salmonella enterica serovar Typhimurium. The RcsC and RcsD proteins form a phosphorelay that activates their cognate regulator RcsB in response to outer membrane stress and cell wall perturbations, conditions Salmonella experiences during infection. Surprisingly, the non-cognate phosphorelay protein BarA activates RcsB during logarithmic growth in Luria-Bertani medium in three ways. That is, BarA’s cognate regulator SirA promotes transcription of the rcsDB operon; the SirA-dependent regulatory RNAs CsrB and CsrC further increase RcsB-activated gene transcription; and BarA activates RcsB independently of the RcsC, RcsD, and SirA proteins. Activation of a regulator by multiple sensors broadens the spectrum of environments in which a set of genes is expressed without evolving binding sites for different regulators at each of these genes. The phosphorelay is a form of signal transduction used by organisms in all three domains of life. Typically, a phosphorelay consists of sensor proteins that respond to specific signals by activating a cognate regulatory protein that alters gene expression. Phosphorelays exhibit specificity towards their cognate regulators, thereby ensuring that any changes in gene expression help an organism cope with the experienced stress (and not with an unrelated stress). However, we now report that the regulator RcsB is activated by both cognate and non-cognate phosphorelay proteins in the bacterium Salmonella enterica serovar Typhimurium. The phosphorelay proteins RcsC and RcsD activate RcsB upon cell envelope perturbations, whereas the non-cognate phosphorelay protein BarA activates RcsB during rapid growth in Luria-Bertani medium. Our findings establish that BarA controls gene expression via both its cognate regulator SirA and the non-cognate regulator RcsB. In addition, they demonstrate that RcsB controls gene expression in response to multiple signals detected by the RcsC, RcsD, and BarA proteins.
Collapse
Affiliation(s)
- Hubert Salvail
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, United States of America
- Yale Microbial Sciences Institute, West Haven, Connecticut, United States of America
| | - Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, United States of America
- Yale Microbial Sciences Institute, West Haven, Connecticut, United States of America
- * E-mail:
| |
Collapse
|
36
|
Lee JH, Ancona V, Chatnaparat T, Yang HW, Zhao Y. The RNA-Binding Protein CsrA Controls Virulence in Erwinia amylovora by Regulating RelA, RcsB, and FlhD at the Posttranscriptional Level. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1448-1459. [PMID: 31140921 DOI: 10.1094/mpmi-03-19-0077-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
CsrA, an RNA-binding protein, binds to target transcripts and alters their translation or stability. In Erwinia amylovora, CsrA positively regulates the expression of type III secretion system (T3SS), exopolysaccharide amylovoran, and motility. In this study, the global effect of CsrA and its noncoding small RNA (ncsRNA) csrB in E. amylovora was determined by RNA-seq, and potential molecular mechanisms of CsrA-dependent virulence regulation were examined. Transcriptomic analyses under the T3SS-inducing condition revealed that mutation in the csrA gene led to differential expression of more than 20% of genes in the genome. Among them, T3SS genes and those required for cell growth and viability were significantly downregulated. On the other hand, the csrB mutant exhibited significant upregulation of most major virulence genes, suggesting an antagonistic effect of csrB on CsrA targets. Direct interaction between CsrA protein and csrB was further confirmed through the RNA electrophoretic mobility shift assay (REMSA). However, no direct interaction between CsrA and hrpL and hrpS transcripts was detected, suggesting that HrpL and HrpS are not targets of CsrA, whereas three CsrA targets (relA, rcsB, and flhD) were identified and confirmed by REMSA, site-directed mutagenesis, and LacZ reporter gene assays. These findings might partially explain how CsrA positively controls E. amylovora virulence by targeting major regulators at the posttranscriptional level.
Collapse
Affiliation(s)
- Jae Hoon Lee
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Veronica Ancona
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Tiyakhon Chatnaparat
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Ho-Wen Yang
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S.A
| |
Collapse
|
37
|
Gao X, Yeom J, Groisman EA. The expanded specificity and physiological role of a widespread N-degron recognin. Proc Natl Acad Sci U S A 2019; 116:18629-18637. [PMID: 31451664 PMCID: PMC6744884 DOI: 10.1073/pnas.1821060116] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
All cells use proteases to maintain protein homeostasis. The proteolytic systems known as the N-degron pathways recognize signals at the N terminus of proteins and bring about the degradation of these proteins. The ClpS protein enforces the N-degron pathway in bacteria and bacteria-derived organelles by targeting proteins harboring leucine, phenylalanine, tryptophan, or tyrosine at the N terminus for degradation by the protease ClpAP. We now report that ClpS binds, and ClpSAP degrades, proteins still harboring the N-terminal methionine. We determine that ClpS recognizes a type of degron in intact proteins based on the identity of the fourth amino acid from the N terminus, showing a strong preference for large hydrophobic amino acids. We uncover natural ClpS substrates in the bacterium Salmonella enterica, including SpoT, the essential synthase/hydrolase of the alarmone (p)ppGpp. Our findings expand both the specificity and physiological role of the widespread N-degron recognin ClpS.
Collapse
Affiliation(s)
- Xiaohui Gao
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536
| | - Jinki Yeom
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536
| | - Eduardo A Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536;
- Yale Microbial Sciences Institute, West Haven, CT 06516
| |
Collapse
|
38
|
Babitzke P, Lai YJ, Renda AJ, Romeo T. Posttranscription Initiation Control of Gene Expression Mediated by Bacterial RNA-Binding Proteins. Annu Rev Microbiol 2019; 73:43-67. [PMID: 31100987 PMCID: PMC9404307 DOI: 10.1146/annurev-micro-020518-115907] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNA-binding proteins play vital roles in regulating gene expression and cellular physiology in all organisms. Bacterial RNA-binding proteins can regulate transcription termination via attenuation or antitermination mechanisms, while others can repress or activate translation initiation by affecting ribosome binding. The RNA targets for these proteins include short repeated sequences, longer single-stranded sequences, RNA secondary or tertiary structure, and a combination of these features. The activity of these proteins can be influenced by binding of metabolites, small RNAs, or other proteins, as well as by phosphorylation events. Some of these proteins regulate specific genes, while others function as global regulators. As the regulatory mechanisms, components, targets, and signaling circuitry surrounding RNA-binding proteins have become better understood, in part through rapid advances provided by systems approaches, a sense of the true nature of biological complexity is becoming apparent, which we attempt to capture for the reader of this review.
Collapse
Affiliation(s)
- Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA; ,
| | - Ying-Jung Lai
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA; ,
| | - Andrew J Renda
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA; ,
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA; ,
| |
Collapse
|
39
|
Abstract
The global regulatory protein CsrA coordinates gene expression in response to physiological cues reflecting cellular stress and nutrition. CsrA binding to the 5' segments of mRNA targets affects their translation, RNA stability, and/or transcript elongation. Recent studies identified probable mRNA targets of CsrA that are involved in iron uptake and storage in Escherichia coli, suggesting an unexplored role for CsrA in regulating iron homeostasis. Here, we assessed the impact of CsrA on iron-related gene expression, cellular iron, and growth under various iron levels. We investigated five new targets of CsrA regulation, including the genes for 4 ferritin or ferritin-like iron storage proteins (ISPs) and the stress-inducible Fe-S repair protein, SufA. CsrA bound with high affinity and specificity to ftnB, bfr, and dps mRNAs and inhibited their translation, while it modestly activated ftnA expression. Furthermore, CsrA was found to regulate cellular iron levels and support growth by repressing the expression of genes for ISPs, most importantly, ferritin B (FtnB) and bacterioferritin (Bfr). Iron starvation did not substantially affect cellular levels of CsrA or its small RNA (sRNA) antagonists, CsrB and CsrC. csrA disruption led to increased resistance to the lethal effects of H2O2 during exponential growth, consistent with a regulatory role in oxidative stress resistance. We propose that during exponential growth and under minimal stress, CsrA represses the deleterious expression of the ISPs that function under oxidative stress and stationary-phase conditions (FtnB, Bfr, and Dps), thus ensuring that cellular iron is available to processes that are required for growth.IMPORTANCE Iron is an essential micronutrient for nearly all living organisms but is toxic in excess. Consequently, the maintenance of iron homeostasis is a critical biological process, and the genes involved in this function are tightly regulated. Here, we explored a new role for the bacterial RNA binding protein CsrA in the regulation of iron homeostasis. CsrA was shown to be a key regulator of iron storage genes in Escherichia coli, with consequential effects on cellular iron levels and growth. Our findings establish a model in which robust CsrA activity during the exponential phase of growth leads to repression of genes whose products sequester iron or divert it to unnecessary stress response processes. In so doing, CsrA supports E. coli growth under iron-limiting laboratory conditions and may promote fitness in the competitive iron-limited environment of the host large intestine.
Collapse
|
40
|
Vibrio cholerae CsrA Directly Regulates varA To Increase Expression of the Three Nonredundant Csr Small RNAs. mBio 2019; 10:mBio.01042-19. [PMID: 31164471 PMCID: PMC6550530 DOI: 10.1128/mbio.01042-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
CsrA, an RNA-binding global regulator, is an essential protein in Vibrio choleraeV. cholerae CsrA is regulated by three small RNAs (sRNAs), namely, CsrB, CsrC, and CsrD, which act to sequester and antagonize the activity of CsrA. Although the sRNAs were considered to be largely redundant, we found that they differ in expression, half-life, and the ability to regulate CsrA. Further, we identified a feedback loop in the Csr system in which CsrA increases the synthesis of these antagonistic sRNAs. Because the Csr sRNAs are positively regulated by VarA, we determined the effects of CsrA on VarA levels. The level of VarA was reduced in a csrA mutant, and we found that CsrA directly bound to varA mRNA in an electrophoretic mobility shift assay in vitro and in an CsrA-RNA immunoprecipitation assay in vivo Thus, varA mRNA is an in vivo-verified direct target of CsrA in V. cholerae, and this is the first demonstration of CsrA directly binding to a varA/uvrY/gacA homolog. Additionally, we demonstrated that a varA translational fusion was less active in a csrA mutant than in wild-type V. cholerae, suggesting that CsrA enhances varA translation. We propose that this autoregulatory feedback loop, in which CsrA increases the production of the nonredundant Csr sRNAs by regulating the amount of VarA, provides a mechanism for fine-tuning the availability of CsrA and, thus, of its downstream targets.IMPORTANCEVibrio cholerae is a major human pathogen, causing epidemics and pandemics of cholera. V. cholerae persists in the aquatic environment, providing a constant source for human infection. Success in transitioning from the environment to the human host and back requires the bacterium to rapidly respond and to adjust its gene expression and metabolism to these two very different habitats. Our findings show that CsrA, an RNA-binding regulatory protein, plays a central role in regulating these transitions. CsrA activity is controlled by the antagonistic sRNAs CsrB, CsrC, and CsrD, and these sRNAs respond to changes in the availability of nutrients. CsrA autoregulates its own activity by controlling these sRNAs via their primary regulator VarA. Thus, the change in CsrA availability in response to nutrient availability allows V. cholerae to alter gene expression in response to environmental cues.
Collapse
|
41
|
Venters BJ. Insights from resolving protein-DNA interactions at near base-pair resolution. Brief Funct Genomics 2019; 17:80-88. [PMID: 29211822 DOI: 10.1093/bfgp/elx043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
One of the central goals in molecular biology is to understand how cell-type-specific expression patterns arise through selective recruitment of RNA polymerase II (Pol II) to a subset of gene promoters. Pol II needs to be recruited to a precise genomic position at the proper time to produce messenger RNA from a DNA template. Ostensibly, transcription is a relatively simple cellular process; yet, experimentally measuring and then understanding the combinatorial possibilities of transcriptional regulators remain a daunting task. Since its introduction in 1985, chromatin immunoprecipitation (ChIP) has remained a key tool for investigating protein-DNA contacts in vivo. Over 30 years of intensive research using ChIP have provided numerous insights into mechanisms of gene regulation. As functional genomic technologies improve, they present new opportunities to address key biological questions. ChIP-exo is a refined version of ChIP-seq that significantly reduces background signal, while providing near base-pair mapping resolution for protein-DNA interactions. This review discusses the evolution of the ChIP assay over the years; the methodological differences between ChIP-seq, ChIP-exo and ChIP-nexus; and highlight new insights into epigenetic and transcriptional mechanisms that were uniquely enabled with the near base-pair resolution of ChIP-exo.
Collapse
|
42
|
Potts AH, Guo Y, Ahmer BMM, Romeo T. Role of CsrA in stress responses and metabolism important for Salmonella virulence revealed by integrated transcriptomics. PLoS One 2019; 14:e0211430. [PMID: 30682134 PMCID: PMC6347204 DOI: 10.1371/journal.pone.0211430] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/14/2019] [Indexed: 12/31/2022] Open
Abstract
To cause infection, Salmonella must survive and replicate in host niches that present dramatically different environmental conditions. This requires a flexible metabolism and physiology, responsive to conditions of the local milieu. The sequence specific RNA binding protein CsrA serves as a global regulator that governs gene expression required for pathogenicity, metabolism, biofilm formation, and motility in response to nutritional conditions. Its activity is determined by two noncoding small RNAs (sRNA), CsrB and CsrC, which sequester and antagonize this protein. Here, we used ribosome profiling and RNA-seq analysis to comprehensively examine the effects of CsrA on mRNA occupancy with ribosomes, a measure of translation, transcript stability, and the steady state levels of transcripts under in vitro SPI-1 inducing conditions, to simulate growth in the intestinal lumen, and under in vitro SPI-2-inducing conditions, to simulate growth in the Salmonella containing vacuole (SCV) of the macrophage. Our findings uncovered new roles for CsrA in controlling the expression of structural and regulatory genes involved in stress responses, metabolism, and virulence systems required for infection. We observed substantial variation in the CsrA regulon under the two growth conditions. In addition, CsrB/C sRNA levels were greatly reduced under the simulated intracellular conditions and were responsive to nutritional factors that distinguish the intracellular and luminal environments. Altogether, our results reveal CsrA to be a flexible regulator, which is inferred to be intimately involved in maintaining the distinct gene expression patterns associated with growth in the intestine and the macrophage.
Collapse
Affiliation(s)
- Anastasia H Potts
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
| | - Yinping Guo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
| | - Brian M M Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States of America
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
| |
Collapse
|
43
|
Abstract
The sequence-specific RNA binding protein CsrA is employed by diverse bacteria in the posttranscriptional regulation of gene expression. Its binding interactions with RNA have been documented at atomic resolution and shown to alter RNA secondary structure, RNA stability, translation, and/or Rho-mediated transcription termination through a growing number of molecular mechanisms. In Gammaproteobacteria, small regulatory RNAs (sRNAs) that contain multiple CsrA binding sites compete with mRNA for binding to CsrA, thereby sequestering and antagonizing this protein. Both the synthesis and turnover of these sRNAs are regulated, allowing CsrA activity to be rapidly and efficiently adjusted in response to nutritional conditions and stresses. Feedback loops between the Csr regulatory components improve the dynamics of signal response by the Csr system. The Csr system of Escherichia coli is intimately interconnected with other global regulatory systems, permitting it to contribute to regulation by those systems. In some species, a protein antagonist of CsrA functions as part of a checkpoint for flagellum biosynthesis. In other species, a protein antagonist participates in a mechanism in which a type III secretion system is used for sensing interactions with host cells. Recent transcriptomics studies reveal vast effects of CsrA on gene expression through direct binding to hundreds of mRNAs, and indirectly through its effects on the expression of dozens of transcription factors. CsrA binding to base-pairing sRNAs and novel mRNA segments, such as the 3' untranslated region and deep within coding regions, predict its participation in yet-to-be-discovered regulatory mechanisms.
Collapse
|
44
|
csrB Gene Duplication Drives the Evolution of Redundant Regulatory Pathways Controlling Expression of the Major Toxic Secreted Metalloproteases in Vibrio tasmaniensis LGP32. mSphere 2018; 3:3/6/e00582-18. [PMID: 30487156 PMCID: PMC6262261 DOI: 10.1128/msphere.00582-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The conserved CsrB sRNAs are an example of sibling sRNAs, i.e., sRNAs which are present in multiple copies in genomes. This report illustrates how new copies arise through gene duplication events and highlights two evolutionary advantages of having such multiple copies: differential regulation of the multiple copies allows integration of different input signals into the regulatory network of which they are parts, and the high redundancy that they provide confers a strong robustness to the system. CsrBs are bacterial highly conserved and multiple-copy noncoding small RNAs (sRNAs) that play major roles in cell physiology and virulence. In the Vibrio genus, they are known to be regulated by the two-component system VarS/VarA. They modulate the well-characterized quorum sensing pathway controlling virulence and luminescence in Vibrio cholerae and Vibrio harveyi, respectively. Remarkably, Vibrio tasmaniensis LGP32, an oyster pathogen that belongs to the Splendidus clade, was found to have four copies of csrB, named csrB1-4, compared to two to three copies in other Vibrio species. Here, we show that the extra csrB4 copy results from a csrB3 gene duplication, a characteristic of the Splendidus clade. Interestingly, csrB genes are regulated in different ways in V. tasmaniensis, with csrB1 expression being independent of the VarS/VarA system. We found that a complex regulatory network involving CsrBs, quorum sensing, and the stationary-phase sigma factor σS redundantly but differentially controls the production of two secreted metalloproteases, Vsm and PrtV, the former being a major determinant of the V. tasmaniensis extracellular product toxicity. In particular, we identified a novel VarS/VarA-dependent but CsrB-independent pathway that controls positively both Vsm production and PrtV production as well as rpoS expression. Altogether, our data show that a csrB gene duplication event in V. tasmaniensis supported the evolution of the regulatory network controlling the expression of major toxic secreted metalloproteases, thereby increasing redundancy and enabling the integration of additional input signals. IMPORTANCE The conserved CsrB sRNAs are an example of sibling sRNAs, i.e., sRNAs which are present in multiple copies in genomes. This report illustrates how new copies arise through gene duplication events and highlights two evolutionary advantages of having such multiple copies: differential regulation of the multiple copies allows integration of different input signals into the regulatory network of which they are parts, and the high redundancy that they provide confers a strong robustness to the system.
Collapse
|
45
|
Santos-Zavaleta A, Sánchez-Pérez M, Salgado H, Velázquez-Ramírez DA, Gama-Castro S, Tierrafría VH, Busby SJW, Aquino P, Fang X, Palsson BO, Galagan JE, Collado-Vides J. A unified resource for transcriptional regulation in Escherichia coli K-12 incorporating high-throughput-generated binding data into RegulonDB version 10.0. BMC Biol 2018; 16:91. [PMID: 30115066 PMCID: PMC6094552 DOI: 10.1186/s12915-018-0555-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/25/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Our understanding of the regulation of gene expression has benefited from the availability of high-throughput technologies that interrogate the whole genome for the binding of specific transcription factors and gene expression profiles. In the case of widely used model organisms, such as Escherichia coli K-12, the new knowledge gained from these approaches needs to be integrated with the legacy of accumulated knowledge from genetic and molecular biology experiments conducted in the pre-genomic era in order to attain the deepest level of understanding possible based on the available data. RESULTS In this paper, we describe an expansion of RegulonDB, the database containing the rich legacy of decades of classic molecular biology experiments supporting what we know about gene regulation and operon organization in E. coli K-12, to include the genome-wide dataset collections from 32 ChIP and 19 gSELEX publications, in addition to around 60 genome-wide expression profiles relevant to the functional significance of these datasets and used in their curation. Three essential features for the integration of this information coming from different methodological approaches are: first, a controlled vocabulary within an ontology for precisely defining growth conditions; second, the criteria to separate elements with enough evidence to consider them involved in gene regulation from isolated transcription factor binding sites without such support; and third, an expanded computational model supporting this knowledge. Altogether, this constitutes the basis for adequately gathering and enabling the comparisons and integration needed to manage and access such wealth of knowledge. CONCLUSIONS This version 10.0 of RegulonDB is a first step toward what should become the unifying access point for current and future knowledge on gene regulation in E. coli K-12. Furthermore, this model platform and associated methodologies and criteria can be emulated for gathering knowledge on other microbial organisms.
Collapse
Affiliation(s)
- Alberto Santos-Zavaleta
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos México
| | - Mishael Sánchez-Pérez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos México
| | - Heladia Salgado
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos México
| | | | - Socorro Gama-Castro
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos México
| | - Víctor H. Tierrafría
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos México
| | | | - Patricia Aquino
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts USA
| | - Xin Fang
- Department of Bioengineering, University of California San Diego, La Jolla, California USA
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California San Diego, La Jolla, California USA
- Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - James E. Galagan
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts USA
| | - Julio Collado-Vides
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos México
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts USA
| |
Collapse
|
46
|
Mendis N, McBride P, Saoud J, Mani T, Faucher SP. The LetA/S two-component system regulates transcriptomic changes that are essential for the culturability of Legionella pneumophila in water. Sci Rep 2018; 8:6764. [PMID: 29712912 PMCID: PMC5928044 DOI: 10.1038/s41598-018-24263-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 03/07/2018] [Indexed: 11/13/2022] Open
Abstract
Surviving the nutrient-poor aquatic environment for extended periods of time is important for the transmission of various water-borne pathogens, including Legionella pneumophila (Lp). Previous work concluded that the stringent response and the sigma factor RpoS are essential for the survival of Lp in water. In the present study, we investigated the role of the LetA/S two-component signal transduction system in the successful survival of Lp in water. In addition to cell size reduction in the post-exponential phase, LetS also contributes to cell size reduction when Lp is exposed to water. Importantly, absence of the sensor kinase results in a significantly lower survival as measured by CFUs in water at various temperatures and an increased sensitivity to heat shock. According to the transcriptomic analysis, LetA/S orchestrates a general transcriptomic downshift of major metabolic pathways upon exposure to water leading to better culturability, and likely survival, suggesting a potential link with the stringent response. However, the expression of the LetA/S regulated small regulatory RNAs, RsmY and RsmZ, is not changed in a relAspoT mutant, which indicates that the stringent response and the LetA/S response are two distinct regulatory systems contributing to the survival of Lp in water.
Collapse
Affiliation(s)
- Nilmini Mendis
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Peter McBride
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Joseph Saoud
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Thangadurai Mani
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Sebastien P Faucher
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada.
| |
Collapse
|
47
|
Reduction in adaptor amounts establishes degradation hierarchy among protease substrates. Proc Natl Acad Sci U S A 2018; 115:E4483-E4492. [PMID: 29686082 DOI: 10.1073/pnas.1722246115] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
ATP-dependent proteases control critical cellular processes, including development, physiology, and virulence. A given protease may recognize a substrate directly via an unfoldase domain or subunit or indirectly via an adaptor that delivers the substrate to the unfoldase. We now report that cells achieve differential stability among substrates of a given protease by modulating adaptor amounts. We establish that the regulatory protein PhoP represses transcription of the gene specifying the ClpAP protease adaptor ClpS when the bacteria Salmonella enterica and Escherichia coli experience low cytoplasmic Mg2+ The resulting decrease in ClpS amounts diminishes proteolysis of several ClpSAP-dependent substrates, including the putrescine aminotransferase Oat, which heightens the formation of antibiotic persisters, and the transcriptional regulators UvrY and PhoP, which alter the expression of genes controlled by these proteins. By contrast, the decrease in ClpS amounts did not impact the abundance of the ClpSAP substrate FtsA, reflecting that FtsA binds to ClpS more tightly than to UvrY and PhoP. Our findings show how physiological conditions that reduce adaptor amounts modify the abundance of selected substrates of a given protease.
Collapse
|
48
|
Lee JH, Ancona V, Zhao Y. Lon protease modulates virulence traits in Erwinia amylovora by direct monitoring of major regulators and indirectly through the Rcs and Gac-Csr regulatory systems. MOLECULAR PLANT PATHOLOGY 2018; 19:827-840. [PMID: 28509355 PMCID: PMC6638003 DOI: 10.1111/mpp.12566] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 05/10/2023]
Abstract
Lon, an ATP-dependent protease in bacteria, influences diverse cellular processes by degrading damaged, misfolded and short-lived regulatory proteins. In this study, we characterized the effects of lon mutation and determined the molecular mechanisms underlying Lon-mediated virulence regulation in Erwinia amylovora, an enterobacterial pathogen of apple. Erwinia amylovora depends on the type III secretion system (T3SS) and the exopolysaccharide (EPS) amylovoran to cause disease. Our results showed that mutation of the lon gene led to the overproduction of amylovoran, increased T3SS gene expression and the non-motile phenotype. Western blot analyses showed that mutation in lon directly affected the accumulation and stability of HrpS/HrpA and RcsA. Mutation in lon also indirectly influenced the expression of flhD, hrpS and csrB through the accumulation of the RcsA/RcsB proteins, which bind to the promoter of these genes. In addition, lon expression is under the control of CsrA, possibly at both the transcriptional and post-transcriptional levels. Although mutation in csrA abolished both T3SS and amylovoran production, deletion of the lon gene in the csrA mutant only rescued amylovoran production, but not T3SS. These results suggest that CsrA might positively control both T3SS and amylovoran production partly by suppressing Lon, whereas CsrA may also play a critical role in T3SS by affecting unknown targets.
Collapse
Affiliation(s)
- Jae Hoon Lee
- Department of Crop SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIL 61801USA
| | - Veronica Ancona
- Department of Crop SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIL 61801USA
- Present address:
Texas A&M University‐Kingsville, Citrus CenterWeslacoTX 78596USA
| | | |
Collapse
|
49
|
Yang X, Wang J, Bing G, Bie P, De Y, Lyu Y, Wu Q. Ortholog-based screening and identification of genes related to intracellular survival. Gene 2018; 651:134-142. [DOI: 10.1016/j.gene.2018.01.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 10/29/2017] [Accepted: 01/17/2018] [Indexed: 12/29/2022]
|
50
|
Examination of Csr regulatory circuitry using epistasis analysis with RNA-seq (Epi-seq) confirms that CsrD affects gene expression via CsrA, CsrB and CsrC. Sci Rep 2018; 8:5373. [PMID: 29599472 PMCID: PMC5876332 DOI: 10.1038/s41598-018-23713-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/19/2018] [Indexed: 01/14/2023] Open
Abstract
The Csr global regulatory system coordinates gene expression in response to metabolic status. This system utilizes the RNA binding protein CsrA to regulate gene expression by binding to transcripts of structural and regulatory genes, thus affecting their structure, stability, translation, and/or transcription elongation. CsrA activity is controlled by sRNAs, CsrB and CsrC, which sequester CsrA away from other transcripts. CsrB/C levels are partly determined by their rates of turnover, which requires CsrD to render them susceptible to RNase E cleavage. Previous epistasis analysis suggested that CsrD affects gene expression through the other Csr components, CsrB/C and CsrA. However, those conclusions were based on a limited analysis of reporters. Here, we reassessed the global behavior of the Csr circuitry using epistasis analysis with RNA seq (Epi-seq). Because CsrD effects on mRNA levels were entirely lost in the csrA mutant and largely eliminated in a csrB/C mutant under our experimental conditions, while the majority of CsrA effects persisted in the absence of csrD, the original model accounts for the global behavior of the Csr system. Our present results also reflect a more nuanced role of CsrA as terminal regulator of the Csr system than has been recognized.
Collapse
|