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Wang H, Waluk D, Dixon R, Nordlund S, Norén A. Energy shifts induce membrane sequestration of DraG in Rhodospirillum rubrum independent of the ammonium transporters and diazotrophic conditions. FEMS Microbiol Lett 2019; 365:5053809. [PMID: 30010831 PMCID: PMC6067124 DOI: 10.1093/femsle/fny176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/10/2018] [Indexed: 01/15/2023] Open
Abstract
Metabolic regulation of Rhodospirillum rubrum nitrogenase is mediated at the post-translational level by the enzymes DraT and DraG when subjected to changes in nitrogen or energy status. DraT is activated during switch-off, while DraG is inactivated by reversible membrane association. We confirm here that the ammonium transporter, AmtB1, rather than its paralog AmtB2, is required for ammonium induced switch-off. Amongst several substitutions at the N100 position in DraG, only N100K failed to locate to the membrane following ammonium shock, suggesting loss of interaction through charge repulsion. When switch-off was induced by lowering energy levels, either by darkness during photosynthetic growth or oxygen depletion under respiratory conditions, reversible membrane sequestration of DraG was independent of AmtB proteins and occurred even under non-diazotrophic conditions. We propose that under these conditions, changes in redox status or possibly membrane potential induce interactions between DraG and another membrane protein in response to the energy status.
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Affiliation(s)
- Helen Wang
- Department of Medical Biochemistry and Microbiology, Uppsala Biomedicinska Centrum, Husarg.3, S-75237 Uppsala, Sweden
| | - Dominik Waluk
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Svante Arrhenius v. 16C, Stockholm S-10691, Sweden
| | - Ray Dixon
- Department of Molecular Microbiology, John Innes Centre, Norwich NR47 UH, UK
| | - Stefan Nordlund
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Svante Arrhenius v. 16C, Stockholm S-10691, Sweden
| | - Agneta Norén
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Svante Arrhenius v. 16C, Stockholm S-10691, Sweden
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Akentieva N. Posttranslational modification of dinitrogenase reductase in Rhodospirillum rubrum treated with fluoroacetate. World J Microbiol Biotechnol 2018; 34:184. [PMID: 30488133 DOI: 10.1007/s11274-018-2564-y] [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: 05/24/2018] [Accepted: 11/20/2018] [Indexed: 10/27/2022]
Abstract
Nitrogen fixation is one of the major biogeochemical contributions carried out by diazotrophic microorganisms. The goal of this research is study of posttranslational modification of dinitrogenase reductase (Fe protein), the involvement of malate and pyruvate in generation of reductant in Rhodospirillum rubrum. A procedure for the isolation of the Fe protein from cell extracts was developed and used to monitor the modification of the Fe protein in vivo. The subunit pattern of the isolated the Fe protein after sodium dodecyl sulfate-polyacrylamide gel electrophoresis was assayed by Western blot analysis. Whole-cell nitrogenase activity was also monitored during the Fe protein modification by gas chromatograpy, using the acetylene reduction assay. It has been shown, that the addition of fluoroacetate, ammonia and darkness resulted in the loss of whole-cell nitrogenase activity and the in vivo modification of the Fe protein. For fluoroacetate, ammonia and darkness, the rate of loss of nitrogenase activity was similar to that for the Fe protein modification. The addition of NADH and reillumination of a culture incubated in the dark resulted in the rapid restoration of nitrogenase activity and the demodification of the Fe protein. Fluoroacetate inhibited the nitrogenase activity of R. rubrum and resulted in the modification of the Fe protein in cells, grown on pyruvate or malate as the endogeneous electron source. The nitrogenase activity in draTG mutant (lacking DRAT/DRAG system) decreased after the addition of fluoroacetate, but the Fe protein remained completely unmodified. The results showed that the reduced state of cell, posttranslational modifications of the Fe protein and the DRAT/DRAG system are important for nitrogenase activity and the regulation of nitrogen fixation.
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Affiliation(s)
- Natalia Akentieva
- Department of Kinetics of Chemical and Biological Processes, Institute of Problems of Chemical Physics, Russian Academy of Sciences, Street Academician Semenov, 1., Chernogolovka, 142432, Moscow Region, Russia.
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Huergo LF, Chandra G, Merrick M. PIIsignal transduction proteins: nitrogen regulation and beyond. FEMS Microbiol Rev 2013; 37:251-83. [DOI: 10.1111/j.1574-6976.2012.00351.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 07/26/2012] [Accepted: 07/26/2012] [Indexed: 01/12/2023] Open
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Huergo LF, Pedrosa FO, Muller-Santos M, Chubatsu LS, Monteiro RA, Merrick M, Souza EM. PII signal transduction proteins: pivotal players in post-translational control of nitrogenase activity. MICROBIOLOGY-SGM 2012; 158:176-190. [PMID: 22210804 DOI: 10.1099/mic.0.049783-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The fixation of atmospheric nitrogen by the prokaryotic enzyme nitrogenase is an energy- expensive process and consequently it is tightly regulated at a variety of levels. In many diazotrophs this includes post-translational regulation of the enzyme's activity, which has been reported in both bacteria and archaea. The best understood response is the short-term inactivation of nitrogenase in response to a transient rise in ammonium levels in the environment. A number of proteobacteria species effect this regulation through reversible ADP-ribosylation of the enzyme, but other prokaryotes have evolved different mechanisms. Here we review current knowledge of post-translational control of nitrogenase and show that, for the response to ammonium, the P(II) signal transduction proteins act as key players.
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Affiliation(s)
- Luciano F Huergo
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Fábio O Pedrosa
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Marcelo Muller-Santos
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Leda S Chubatsu
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Rose A Monteiro
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Mike Merrick
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, UK
| | - Emanuel M Souza
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
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Selao TT, Edgren T, Wang H, Norén A, Nordlund S. Effect of pyruvate on the metabolic regulation of nitrogenase activity in Rhodospirillum rubrum in darkness. MICROBIOLOGY-SGM 2011; 157:1834-1840. [PMID: 21393366 DOI: 10.1099/mic.0.045831-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Rhodospirillum rubrum, a photosynthetic diazotroph, is able to regulate nitrogenase activity in response to environmental factors such as ammonium ions or darkness, the so-called switch-off effect. This is due to reversible modification of the Fe-protein, one of the two components of nitrogenase. The signal transduction pathway(s) in this regulatory mechanism is not fully understood, especially not in response to darkness. We have previously shown that the switch-off response and metabolic state differ between cells grown with dinitrogen or glutamate as the nitrogen source, although both represent poor nitrogen sources. In this study we show that pyruvate affects the response to darkness in cultures grown with glutamate as nitrogen source, leading to a response similar to that in cultures grown with dinitrogen. The effects are related to P(II) protein uridylylation and glutamine synthetase activity. We also show that pyruvate induces de novo protein synthesis and that inhibition of pyruvate formate-lyase leads to loss of nitrogenase activity in the dark.
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Affiliation(s)
- Tiago Toscano Selao
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Tomas Edgren
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
| | - He Wang
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Agneta Norén
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Stefan Nordlund
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
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Teixeira PF, Selao TT, Henriksson V, Wang H, Norén A, Nordlund S. Diazotrophic growth of Rhodospirillum rubrum with 2-oxoglutarate as sole carbon source affects regulation of nitrogen metabolism as well as the soluble proteome. Res Microbiol 2010; 161:651-9. [PMID: 20600859 DOI: 10.1016/j.resmic.2010.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 06/02/2010] [Accepted: 06/08/2010] [Indexed: 10/19/2022]
Abstract
2-Oxoglutarate plays a central role as a signal in the regulation of nitrogen metabolism in the phototrophic diazotroph Rhodospirillum rubrum. In order to further study the role of this metabolite, we have constructed an R. rubrum strain that has the capacity to grow on 2-oxoglutarate as sole carbon source, in contrast to wild-type R. rubrum. This strain has the same growth characteristics as wild-type with malate as carbon source, but showed clear metabolic differences when 2-oxoglutarate was used. Among other things, the regulation of nitrogen metabolism is altered, which can be related to different modification profiles of the regulatory PII proteins.
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Affiliation(s)
- Pedro Filipe Teixeira
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
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