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Cerna‐Vargas JP, Krell T. Exploring solute binding proteins in Pseudomonas aeruginosa that bind to γ-aminobutyrate and 5-aminovalerate and their role in activating sensor kinases. Microbiologyopen 2024; 13:e1415. [PMID: 38780167 PMCID: PMC11113362 DOI: 10.1002/mbo3.1415] [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: 04/08/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024] Open
Abstract
The standard method of receptor activation involves the binding of signals or signal-loaded solute binding proteins (SBPs) to sensor domains. Many sensor histidine kinases (SHKs), which are activated by SBP binding, are encoded adjacent to their corresponding sbp gene. We examined three SBPs of Pseudomonas aeruginosa PAO1, encoded near the genes for the AgtS (PA0600) and AruS (PA4982) SHKs, to determine how common this arrangement is. Ligand screening and microcalorimetric studies revealed that the SBPs PA0602 and PA4985 preferentially bind to GABA (KD = 2.3 and 0.58 μM, respectively), followed by 5-aminovalerate (KD = 30 and 1.6 μM, respectively) and ethanoldiamine (KD = 2.3 and 0.58 μM, respectively). In contrast, AgtB (PA0604) exclusively recognizes 5-aminovaleric acid (KD = 2.9 μM). However, microcalorimetric titrations did not show any binding between the AgtS sensor domain and AgtB or PA0602, regardless of the presence of ligands. Similarly, bacterial two-hybrid assays did not demonstrate an interaction between PA4985 and the AruS sensor domain. Therefore, sbp and shk genes located nearby are not always functionally linked. We previously identified PA0222 as a GABA-specific SBP. The presence of three SBPs for GABA may be linked to GABA's role as a trigger for P. aeruginosa virulence.
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Affiliation(s)
- Jean Paul Cerna‐Vargas
- Department of Biotechnology and Environmental Protection, Estación Experimental del ZaidínConsejo Superior de Investigaciones CientíficasGranadaSpain
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/Consejo Superior de Investigaciones CientíficasParque Científico y Tecnológico de la Universidad Politécnica de Madrid, Pozuelo de AlarcónMadridSpain
| | - Tino Krell
- Department of Biotechnology and Environmental Protection, Estación Experimental del ZaidínConsejo Superior de Investigaciones CientíficasGranadaSpain
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Budnick JA, Sheehan LM, Benton AH, Pitzer JE, Kang L, Michalak P, Roop RM, Caswell CC. Characterizing the transport and utilization of the neurotransmitter GABA in the bacterial pathogen Brucella abortus. PLoS One 2020; 15:e0237371. [PMID: 32845904 PMCID: PMC7449393 DOI: 10.1371/journal.pone.0237371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 08/04/2020] [Indexed: 01/18/2023] Open
Abstract
The neurotransmitter gamma-aminobutyric acid (GABA) is the most abundant inhibitory neurotransmitter in the human brain; however, it is becoming more evident that this non-proteinogenic amino acid plays multiple physiological roles in biology. In the present study, the transport and function of GABA is studied in the highly infectious intracellular bacterium Brucella abortus. The data show that 3H-GABA is imported by B. abortus under nutrient limiting conditions and that the small RNAs AbcR1 and AbcR2 negatively regulate this transport. A specific transport system, gts, is responsible for the transport of GABA as determined by measuring 3H-GABA transport in isogenic deletion strains of known AbcR1/2 regulatory targets; however, this locus is unnecessary for Brucella infection in BALB/c mice. Similar assays revealed that 3H-GABA transport is uninhibited by the 20 standard proteinogenic amino acids, representing preference for the transport of 3H-GABA. Metabolic studies did not show any potential metabolic utilization of GABA by B. abortus as a carbon or nitrogen source, and RNA sequencing analysis revealed limited transcriptional differences between B. abortus 2308 with or without exposure to GABA. While this study provides evidence for GABA transport by B. abortus, questions remain as to why and when this transport is utilized during Brucella pathogenesis.
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Affiliation(s)
- James A. Budnick
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
| | - Lauren M. Sheehan
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
| | - Angela H. Benton
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
| | - Joshua E. Pitzer
- Department of Microbiology and Immunology, East Carolina University Brody School of Medicine, Greenville, North Carolina, United States of America
| | - Lin Kang
- Center for One Health Research, Blacksburg, Virginia, United States of America
- Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, United States of America
| | - Pawel Michalak
- Center for One Health Research, Blacksburg, Virginia, United States of America
- Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, United States of America
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - R. Martin Roop
- Department of Microbiology and Immunology, East Carolina University Brody School of Medicine, Greenville, North Carolina, United States of America
| | - Clayton C. Caswell
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
- * E-mail:
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Nonaka S, Someya T, Kadota Y, Nakamura K, Ezura H. Super- Agrobacterium ver. 4: Improving the Transformation Frequencies and Genetic Engineering Possibilities for Crop Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:1204. [PMID: 31649690 PMCID: PMC6791131 DOI: 10.3389/fpls.2019.01204] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 09/02/2019] [Indexed: 05/07/2023]
Abstract
Agrobacterium tumefaciens has been utilized for both transient and stable transformations of plants. These transformation methods have been used in fields such as breeding GM crops, protein production in plant cells, and the functional analysis of genes. However, some plants have significantly lower transient gene transfer and stable transformation rates, creating a technical barrier that needs to be resolved. In this study, Super-Agrobacterium was updated to ver. 4 by introducing both the ACC deaminase (acdS) and GABA transaminase (gabT) genes, whose resultant enzymes degrade ACC, the ethylene precursor, and GABA, respectively. A. tumefaciens strain GV2260, which is similar to other major strains (EHA105, GV3101, LBA4404, and MP90), was used in this study. The abilities of the Super-Agrobacterium ver. 4 were evaluated in Erianthus ravennae, Solanum lycopersicum "Micro-Tom," Nicotiana benthamiana, and S. torvum. Super-Agrobacterium ver. 4 showed the highest T-DNA transfer (transient transformation) frequencies in E. ravennae and S. lycopersicum, but not in N. benthamiana and S. torvum. In tomato, Super-Agrobacterium ver. 4 increased the stable transformation rate by 3.6-fold compared to the original GV2260 strain. Super-Agrobacterium ver. 4 enables reduction of the amount of time and labor required for transformations by approximately 72%, and is therefore a more effective and powerful tool for plant genetic engineering and functional analysis, than the previously developed strains. As our system has a plasmid containing the acdS and gabT genes, it could be used in combination with other major strains such as EHA105, EHA101, LBA4404, MP90, and AGL1. Super-Agrobacterium ver. 4, could thus possibly be a breakthrough application for improving basic plant science research methods.
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Affiliation(s)
- Satoko Nonaka
- Tsukuba Plant Innovation Research Center, Gene Research Center, University of Tsukuba, Tsukuba, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
- *Correspondence: Satoko Nonaka, ; Hiroshi Ezura,
| | - Tatsuhiko Someya
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yasuhiro Kadota
- RIKEN Center for Sustainable Resource Science, Plant Immunity Group, Yokohama, Japan
| | - Kouji Nakamura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Hiroshi Ezura
- Tsukuba Plant Innovation Research Center, Gene Research Center, University of Tsukuba, Tsukuba, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
- *Correspondence: Satoko Nonaka, ; Hiroshi Ezura,
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Podlešáková K, Ugena L, Spíchal L, Doležal K, De Diego N. Phytohormones and polyamines regulate plant stress responses by altering GABA pathway. N Biotechnol 2018; 48:53-65. [PMID: 30048769 DOI: 10.1016/j.nbt.2018.07.003] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 06/20/2018] [Accepted: 07/21/2018] [Indexed: 11/16/2022]
Abstract
In plants, γ-aminobutyric acid (GABA) accumulates rapidly in response to environmental stress and variations in its endogenous concentration have been shown to affect plant growth. Exogenous application of GABA has also conferred higher stress tolerance by modulating the expression of genes involved in plant signalling, transcriptional regulation, hormone biosynthesis, reactive oxygen species production and polyamine metabolism. Plant hormones play critical roles in adaptation of plants to adverse environmental conditions through a sophisticated crosstalk among them. Several studies have provided evidence for the relationships between GABA, polyamines and hormones such as abscisic acid, cytokinins, auxins, gibberellins and ethylene, among others, focussing on the effect that one specific group of compounds exerts over the metabolic and signalling pathways of others. In this review, we bring together information obtained from plants exposed to several stress conditions and discuss the possible links among these different groups of molecules. The analysis supports the view that highly conserved pathways connect primary and secondary metabolism, with an overlap of regulatory functions related to stress responses and tolerance among phytohormones, amino acids and polyamines.
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Affiliation(s)
- Kateřina Podlešáková
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic.
| | - Lydia Ugena
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic.
| | - Lukáš Spíchal
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic.
| | - Karel Doležal
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic.
| | - Nuria De Diego
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic.
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Becker A, Overlöper A, Schlüter JP, Reinkensmeier J, Robledo M, Giegerich R, Narberhaus F, Evguenieva-Hackenberg E. Riboregulation in plant-associated α-proteobacteria. RNA Biol 2014; 11:550-62. [PMID: 25003187 DOI: 10.4161/rna.29625] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The symbiotic α-rhizobia Sinorhizobium meliloti, Bradyrhizobium japonicum, Rhizobium etli and the related plant pathogen Agrobacterium tumefaciens are important model organisms for studying plant-microbe interactions. These metabolically versatile soil bacteria are characterized by complex lifestyles and large genomes. Here we summarize the recent knowledge on their small non-coding RNAs (sRNAs) including conservation, function, and interaction of the sRNAs with the RNA chaperone Hfq. In each of these organisms, an inventory of hundreds of cis- and trans-encoded sRNAs with regulatory potential was uncovered by high-throughput approaches and used for the construction of 39 sRNA family models. Genome-wide analyses of hfq mutants and co-immunoprecipitation with tagged Hfq revealed a major impact of the RNA chaperone on the physiology of plant-associated α-proteobacteria including symbiosis and virulence. Highly conserved members of the SmelC411 family are the AbcR sRNAs, which predominantly regulate ABC transport systems. AbcR1 of A. tumefaciens controls the uptake of the plant-generated signaling molecule GABA and is a central regulator of nutrient uptake systems. It has similar functions in S. meliloti and the human pathogen Brucella abortus. As RNA degradation is an important process in RNA-based gene regulation, a short overview on ribonucleases in plant-associated α-proteobacteria concludes this review.
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Affiliation(s)
- Anke Becker
- LOEWE Centre for Synthetic Microbiology and Faculty of Biology; Philipps-Universität Marburg; Marburg, Germany
| | | | - Jan-Philip Schlüter
- LOEWE Centre for Synthetic Microbiology and Faculty of Biology; Philipps-Universität Marburg; Marburg, Germany
| | - Jan Reinkensmeier
- Center for Biotechnology (CeBiTec); Bielefeld University; Bielefeld, Germany
| | - Marta Robledo
- LOEWE Centre for Synthetic Microbiology and Faculty of Biology; Philipps-Universität Marburg; Marburg, Germany
| | - Robert Giegerich
- Center for Biotechnology (CeBiTec); Bielefeld University; Bielefeld, Germany
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Overlöper A, Kraus A, Gurski R, Wright PR, Georg J, Hess WR, Narberhaus F. Two separate modules of the conserved regulatory RNA AbcR1 address multiple target mRNAs in and outside of the translation initiation region. RNA Biol 2014; 11:624-40. [PMID: 24921646 PMCID: PMC4152367 DOI: 10.4161/rna.29145] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The small RNA AbcR1 regulates the expression of ABC transporters in the plant pathogen Agrobacterium tumefaciens, the plant symbiont Sinorhizobium meliloti, and the human pathogen Brucella abortus. A combination of proteomic and bioinformatic approaches suggested dozens of AbcR1 targets in A. tumefaciens. Several of these newly discovered targets are involved in the uptake of amino acids, their derivatives, and sugars. Among the latter is the periplasmic sugar-binding protein ChvE, a component of the virulence signal transduction system. We examined 16 targets and their interaction with AbcR1 in close detail. In addition to the previously described mRNA interaction site of AbcR1 (M1), the CopraRNA program predicted a second functional module (M2) as target-binding site. Both M1 and M2 contain single-stranded anti-SD motifs. Using mutated AbcR1 variants, we systematically tested by band shift experiments, which sRNA region is responsible for mRNA binding and gene regulation. On the target site, we find that AbcR1 interacts with some mRNAs in the translation initiation region and with others far into their coding sequence. Our data show that AbcR1 is a versatile master regulator of nutrient uptake systems in A. tumefaciens and related bacteria.
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Affiliation(s)
| | | | | | - Patrick R Wright
- Genetics and Experimental Bioinformatics; University of Freiburg; Germany
| | - Jens Georg
- Genetics and Experimental Bioinformatics; University of Freiburg; Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics; University of Freiburg; Germany
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