1
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Omedes S, Crespo-Picazo JL, Robinson NJ, García-Párraga D, Sole M. Identifying biomarkers of pollutant exposure in ocean sentinels: Characterisation and optimisation of B-esterases in plasma from loggerhead turtles undergoing rehabilitation. Chemosphere 2024; 348:140770. [PMID: 37992900 DOI: 10.1016/j.chemosphere.2023.140770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 11/09/2023] [Accepted: 11/18/2023] [Indexed: 11/24/2023]
Abstract
Sea turtles are frequently proposed as indicator species for assessing ocean health. To faciliate the use of these species as bioindicators requires the development of tools for rapidly and effectively assessing individual health. Here, we collected 104 blood samples from 69 loggerhead sea turtles, Caretta caretta, undergoing rehabilitation to determine the connection between health status, the activity of B-esterases, and other biochemical parameters. To determine the optimal assay protocol for B-esterases, we measured the activity and kinetics of cholinesterases-(ChEs) and carboxylesterases (CEs) using 3 and 5 commercial substrates, respectively, at different assay conditions. IC50 values for the activity of B-esterases were calculated within a concentration range for model pesticide inhibitors. Turtles' health status was determined via routine veterinary procedures. During rehabilitation (which was associated with improving health status), we observed a decrease in the activity of most enzymes (especially in acetylcholinesterase) alongside an increase in CE when using p-nitrophenyl acetate as a substrate. As such, it is possible that the activity rates of plasmatic B-esterases could serve as an indicator of health status. There is also high potential that B-esterases could be specifically sensitive to marine pollutants although to further validate this would require future studies to specifically correlate B-esterarse activities to pollutant concentrations in blood or excreta.
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Affiliation(s)
- S Omedes
- Institut de Ciències del Mar, CSIC, Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain
| | - J L Crespo-Picazo
- Fundació Oceanogràfic de la Comunitat Valenciana, Gran Vía Marques del Turia 19, 46005, Valencia, Spain
| | - N J Robinson
- Institut de Ciències del Mar, CSIC, Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain; Fundació Oceanogràfic de la Comunitat Valenciana, Gran Vía Marques del Turia 19, 46005, Valencia, Spain
| | - D García-Párraga
- Fundació Oceanogràfic de la Comunitat Valenciana, Gran Vía Marques del Turia 19, 46005, Valencia, Spain
| | - M Sole
- Institut de Ciències del Mar, CSIC, Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain.
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2
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Young TR, Deery E, Foster AW, Martini MA, Osman D, Warren MJ, Robinson NJ. Two Distinct Thermodynamic Gradients for Cellular Metalation of Vitamin B 12. JACS Au 2023; 3:1472-1483. [PMID: 37234125 PMCID: PMC10206600 DOI: 10.1021/jacsau.3c00119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/13/2023] [Accepted: 04/25/2023] [Indexed: 05/27/2023]
Abstract
The acquisition of CoII by the corrin component of vitamin B12 follows one of two distinct pathways, referred to as early or late CoII insertion. The late insertion pathway exploits a CoII metallochaperone (CobW) from the COG0523 family of G3E GTPases, while the early insertion pathway does not. This provides an opportunity to contrast the thermodynamics of metalation in a metallochaperone-requiring and a metallochaperone-independent pathway. In the metallochaperone-independent route, sirohydrochlorin (SHC) associates with the CbiK chelatase to form CoII-SHC. CoII-buffered enzymatic assays indicate that SHC binding enhances the thermodynamic gradient for CoII transfer from the cytosol to CbiK. In the metallochaperone-dependent pathway, hydrogenobyrinic acid a,c-diamide (HBAD) associates with the CobNST chelatase to form CoII-HBAD. Here, CoII-buffered enzymatic assays indicate that CoII transfer from the cytosol to HBAD-CobNST must somehow traverse a highly unfavorable thermodynamic gradient for CoII binding. Notably, there is a favorable gradient for CoII transfer from the cytosol to the MgIIGTP-CobW metallochaperone, but further transfer of CoII from the GTP-bound metallochaperone to the HBAD-CobNST chelatase complex is thermodynamically unfavorable. However, after nucleotide hydrolysis, CoII transfer from the chaperone to the chelatase complex is calculated to become favorable. These data reveal that the CobW metallochaperone can overcome an unfavorable thermodynamic gradient for CoII transfer from the cytosol to the chelatase by coupling this process to GTP hydrolysis.
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Affiliation(s)
- Tessa R. Young
- Department
of Biosciences, Durham University, Durham DH1 3LE, U.K.
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
| | - Evelyne Deery
- School
of Biosciences, University of Kent, Canterbury CT2 7NJ, U.K.
| | - Andrew W. Foster
- Department
of Biosciences, Durham University, Durham DH1 3LE, U.K.
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
| | - Maria Alessandra Martini
- Department
of Biosciences, Durham University, Durham DH1 3LE, U.K.
- Department
of Inorganic Spectroscopy, Max Planck Institute
for Chemical Energy Conversion, 45470 Mülheim an der Ruhr, Germany
| | - Deenah Osman
- Department
of Biosciences, Durham University, Durham DH1 3LE, U.K.
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
| | - Martin J. Warren
- School
of Biosciences, University of Kent, Canterbury CT2 7NJ, U.K.
- Quadram
Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, U.K.
| | - Nigel J. Robinson
- Department
of Biosciences, Durham University, Durham DH1 3LE, U.K.
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
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3
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Abstract
Metalation, the acquisition of metals by proteins, must avoid mis-metalation with tighter binding metals. This is illustrated by four selected proteins that require different metals: all show similar ranked orders of affinity for bioavailable metals, as described in a universal affinity series (the Irving-Williams series). Crucially, cellular protein metalation occurs in competition with other metal binding sites. The strength of this competition defines the intracellular availability of each metal: its magnitude has been estimated by calibrating a cells' set of DNA-binding, metal-sensing, transcriptional regulators. This has established that metal availabilities (as free energies for forming metal complexes) are maintained to the inverse of the universal series. The tightest binding metals are least available. With these availabilities, correct metalation is achieved.
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Affiliation(s)
- Deenah Osman
- Department of Biosciences, University of Durham, UK.,Department of Chemistry, University of Durham, UK
| | - Nigel J Robinson
- Department of Biosciences, University of Durham, UK.,Department of Chemistry, University of Durham, UK
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4
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Foster AW, Clough SE, Aki Z, Young TR, Clarke AR, Robinson NJ. Metalation calculators for E. coli strain JM109 (DE3): Aerobic, anaerobic and hydrogen peroxide exposed cells cultured in LB media. Metallomics 2022; 14:6657815. [PMID: 35933161 PMCID: PMC9434800 DOI: 10.1093/mtomcs/mfac058] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/24/2022] [Indexed: 11/14/2022]
Abstract
Three web-based calculators, and three analogous spreadsheets, have been generated that predict in vivo metal occupancies of proteins based on known metal affinities. The calculations exploit estimates of the availabilities of the labile buffered pools of different metals inside a cell. Here, metal availabilities have been estimated for a strain of E. coli that is commonly used in molecular biology and biochemistry research, for example in the production of recombinant proteins. Metal availabilities have been examined for cells grown in LB medium aerobically, anaerobically and in response to H2O2 by monitoring the abundance of a selected set of metal-responsive transcripts by qPCR. The selected genes are regulated by DNA-binding metal sensors that have been thermodynamically characterised in related bacterial cells enabling gene expression to be read-out as a function of intracellular metal availabilities expressed as free energies for forming metal complexes. The calculators compare these values with the free energies for forming complexes with the protein of interest, derived from metal affinities, to estimate how effectively the protein can compete with exchangeable binding sites in the intracellular milieu. The calculators then inter-compete the different metals, limiting total occupancy of the site to a maximum stoichiometry of 1, to output percentage occupancies with each metal. In addition to making these new and conditional calculators available, an original purpose of this article was to provide a tutorial which discusses constraints of this approach and presents ways in which such calculators might be exploited in basic and applied research, and in next-generation manufacturing.
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Affiliation(s)
- Andrew W Foster
- Department of Biosciences, Durham University, Durham, UK.,Department of Chemistry, Durham University, Durham, UK
| | - Sophie E Clough
- Department of Biosciences, Durham University, Durham, UK.,Department of Chemistry, Durham University, Durham, UK
| | - Zeynep Aki
- Advanced Research Computing, Durham University, Durham, UK
| | - Tessa R Young
- Department of Biosciences, Durham University, Durham, UK.,Department of Chemistry, Durham University, Durham, UK
| | | | - Nigel J Robinson
- Department of Biosciences, Durham University, Durham, UK.,Department of Chemistry, Durham University, Durham, UK
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5
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Abstract
Inorganic metals supplement the chemical repertoire of organic molecules, especially proteins. This requires the correct metals to associate with proteins at metalation. Protein mismetalation typically occurs when excesses of unbound metals compete for a binding site ex vivo. However, in biology, excesses of metal-binding sites typically compete for limiting amounts of exchangeable metals. Here, we summarise mechanisms of metal homeostasis that sustain optimal metal availabilities in biology. We describe recent progress to understand metalation by comparing the strength of metal binding to a protein versus the strength of binding to competing sites inside cells.
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Affiliation(s)
- Andrew W Foster
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK; Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Tessa R Young
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK; Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Peter T Chivers
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK; Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Nigel J Robinson
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK; Department of Chemistry, Durham University, Durham, DH1 3LE, UK.
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6
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Osman D, Cooke A, Young TR, Deery E, Robinson NJ, Warren MJ. The requirement for cobalt in vitamin B 12: A paradigm for protein metalation. Biochim Biophys Acta Mol Cell Res 2021; 1868:118896. [PMID: 33096143 PMCID: PMC7689651 DOI: 10.1016/j.bbamcr.2020.118896] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/20/2022]
Abstract
Vitamin B12, cobalamin, is a cobalt-containing ring-contracted modified tetrapyrrole that represents one of the most complex small molecules made by nature. In prokaryotes it is utilised as a cofactor, coenzyme, light sensor and gene regulator yet has a restricted role in assisting only two enzymes within specific eukaryotes including mammals. This deployment disparity is reflected in another unique attribute of vitamin B12 in that its biosynthesis is limited to only certain prokaryotes, with synthesisers pivotal in establishing mutualistic microbial communities. The core component of cobalamin is the corrin macrocycle that acts as the main ligand for the cobalt. Within this review we investigate why cobalt is paired specifically with the corrin ring, how cobalt is inserted during the biosynthetic process, how cobalt is made available within the cell and explore the cellular control of cobalt and cobalamin levels. The partitioning of cobalt for cobalamin biosynthesis exemplifies how cells assist metalation.
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Affiliation(s)
- Deenah Osman
- Department of Biosciences, Durham University, Durham DH1 3LE, UK; Department of Chemistry, Durham University, Durham DH1 3LE, UK.
| | - Anastasia Cooke
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK.
| | - Tessa R Young
- Department of Biosciences, Durham University, Durham DH1 3LE, UK; Department of Chemistry, Durham University, Durham DH1 3LE, UK.
| | - Evelyne Deery
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK.
| | - Nigel J Robinson
- Department of Biosciences, Durham University, Durham DH1 3LE, UK; Department of Chemistry, Durham University, Durham DH1 3LE, UK.
| | - Martin J Warren
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK; Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK; Biomedical Research Centre, University of East Anglia, Norwich NR4 7TJ, UK.
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7
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Robinson NJ, Deguzman K, Bonacci-Sullivan L, DiGiovanni RA, Pinou T. Rehabilitated sea turtles tend to resume typical migratory behaviors: satellite tracking juvenile loggerhead, green, and Kemp’s ridley turtles in the northeastern USA. ENDANGER SPECIES RES 2020. [DOI: 10.3354/esr01065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Wildlife rehabilitation programs are widely employed for many endangered marine species and can serve as engaging platforms for environmental outreach. However, their effectiveness at supporting populations in the wild depends on whether rescued animals can survive and reproduce after being released. Here, we assessed whether cold-stunned juvenile sea turtles resumed typical migratory and diving behaviors after rehabilitation. We deployed satellite transmitters onto 7 rehabilitated loggerhead turtles Caretta caretta, 12 green turtles Chelonia mydas, and 12 Kemp’s ridley turtles Lepidochelys kempii released around Long Island, New York, USA. Of these 31 turtles, 30 were tracked long enough to determine their migratory movements. The majority (83%) left Long Island before local waters dropped below 14°C and avoided being cold-stunned. Most individuals followed migratory routes previously reported for each of the 3 species, migrating to either coastal waters off the southeast USA or oceanic waters of the Gulf Stream. Rehabilitated turtles of each species also resumed typical diving patterns. Four of the remaining 5 turtles that did not migrate away from Long Island were likely cold-stunned again. Overall, most cold-stunned sea turtles tend to resume typical migratory and diving behavior post-rehabilitation.
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Affiliation(s)
- NJ Robinson
- Fundación Oceanogràfic, Ciudad de Las Artes y las Ciencias, Valencia 46013, Spain
- Western Connecticut State University, Danbury, Connecticut 06810, USA
| | - K Deguzman
- Western Connecticut State University, Danbury, Connecticut 06810, USA
| | - L Bonacci-Sullivan
- New York State Department of Environmental Conservation, Albany, New York 12233, USA
| | - RA DiGiovanni
- Riverhead Foundation for Marine Research and Preservation, Riverhead, New York 11901, USA
- Atlantic Marine Conservation Society, Hampton Bays, New York 11946, USA
| | - T Pinou
- Western Connecticut State University, Danbury, Connecticut 06810, USA
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8
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Osman D, Martini MA, Foster AW, Chen J, Scott AJP, Morton RJ, Steed JW, Lurie-Luke E, Huggins TG, Lawrence AD, Deery E, Warren MJ, Chivers PT, Robinson NJ. Bacterial sensors define intracellular free energies for correct enzyme metalation. Nat Chem Biol 2019; 15:241-249. [PMID: 30692683 PMCID: PMC6420079 DOI: 10.1038/s41589-018-0211-4] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 12/04/2018] [Indexed: 01/06/2023]
Abstract
There is a challenge for metalloenzymes to acquire their correct metals because some inorganic elements form more stable complexes with proteins than do others. These preferences can be overcome provided some metals are more available than others. However, while the total amount of cellular metal can be readily measured, the available levels of each metal have been more difficult to define. Metal-sensing transcriptional regulators are tuned to the intracellular availabilities of their cognate ions. Here we have determined the standard free energy for metal complex formation to which each sensor, in a set of bacterial metal sensors, is attuned: The less competitive the metal, the less favorable the free energy and hence greater availability to which the cognate allosteric mechanism is tuned. Comparing these free energies with values derived from the metal affinities of a metalloprotein reveals the mechanism of correct metalation exemplified here by a cobalt-chelatase for vitamin B12.
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Affiliation(s)
- Deenah Osman
- Department of Biosciences, Durham University, Durham, UK.,Department of Chemistry, Durham University, Durham, UK
| | | | - Andrew W Foster
- Department of Biosciences, Durham University, Durham, UK.,Department of Chemistry, Durham University, Durham, UK
| | - Junjun Chen
- Procter and Gamble, Mason Business Center, Cincinnati, OH, USA
| | | | - Richard J Morton
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle-upon-Tyne, UK
| | | | | | | | | | - Evelyne Deery
- School of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Martin J Warren
- School of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Peter T Chivers
- Department of Biosciences, Durham University, Durham, UK. .,Department of Chemistry, Durham University, Durham, UK.
| | - Nigel J Robinson
- Department of Biosciences, Durham University, Durham, UK. .,Department of Chemistry, Durham University, Durham, UK.
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9
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Robinson NJ, Belshaw Z, Brennan ML, Dean RS. Measuring the success of canine and feline preventative healthcare consultations: A systematic review. Prev Vet Med 2018; 158:18-24. [PMID: 30220392 DOI: 10.1016/j.prevetmed.2018.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/20/2018] [Accepted: 07/04/2018] [Indexed: 11/28/2022]
Abstract
Preventative healthcare consultations account for a large proportion of the veterinary caseload. This novel study is the first to methodically review all literature on canine and feline preventative healthcare consultations. Previous research has found these consultations to be different from health problem consultations in terms of communication style and content. Identifying relevant evidence and previously validated methods of measuring the success of these consultations will be useful when implementing strategies for optimisation. The aim of this study was to identify and assess the quality of existing literature which describes and/or measures the success of preventative healthcare consultations. Database searches of CAB Abstracts and Medline were conducted to identify published literature. Google searches were then conducted to identify any additional published or grey literature. Results were systematically screened to determine whether the returned sources were about cats and/or dogs, whether they related to preventative healthcare, and whether they described and/or measured the success of preventative healthcare consultations. For primary research citations which only described preventative healthcare consultations, data were extracted on the aspects of the consultations described. For citations which additionally measured the success of the consultations, the measures used, sampling technique, key results and key weaknesses were also extracted. Of 17,538 citations identified in total during the database searches, a total of seven relevant primary research citations were identified. All of these citations described aspects of the preventative healthcare consultation, such as consultation length, health problems discussed, actions taken and communication style. Only one primary research citation measured success of the consultation, using veterinarian satisfaction to determine success. In addition, 30 narrative citations, including expert opinion pieces, textbooks, guidelines without transparent methodology and conference presentations were identified. Google searches identified 224 relevant narrative citations, and five of the seven primary research citations identified by the database searches, but did not identify any additional relevant primary research citations. The results suggest that, despite accounting for around a third of all consultations, there is relatively little evidence describing preventative healthcare consultations and only one measure of success has been described for these consultations. This presents potential challenges when implementing strategies to optimise these consultations, as measures which are useful and relevant to veterinary practice should first be identified. Identifying useful measures of success will allow future strategies designed to maximise the benefits of these consultations to be meaningfully assessed for efficacy.
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.
| | - Z Belshaw
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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10
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Rees AF, Avens L, Ballorain K, Bevan E, Broderick AC, Carthy RR, Christianen MJA, Duclos G, Heithaus MR, Johnston DW, Mangel JC, Paladino F, Pendoley K, Reina RD, Robinson NJ, Ryan R, Sykora-Bodie ST, Tilley D, Varela MR, Whitman ER, Whittock PA, Wibbels T, Godley BJ. The potential of unmanned aerial systems for sea turtle research and conservation: a review and future directions. ENDANGER SPECIES RES 2018. [DOI: 10.3354/esr00877] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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11
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Osman D, Foster AW, Chen J, Svedaite K, Steed JW, Lurie-Luke E, Huggins TG, Robinson NJ. Fine control of metal concentrations is necessary for cells to discern zinc from cobalt. Nat Commun 2017; 8:1884. [PMID: 29192165 PMCID: PMC5709419 DOI: 10.1038/s41467-017-02085-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 11/06/2017] [Indexed: 12/31/2022] Open
Abstract
Bacteria possess transcription factors whose DNA-binding activity is altered upon binding to specific metals, but metal binding is not specific in vitro. Here we show that tight regulation of buffered intracellular metal concentrations is a prerequisite for metal specificity of Zur, ZntR, RcnR and FrmR in Salmonella Typhimurium. In cells, at non-inhibitory elevated concentrations, Zur and ZntR, only respond to Zn(II), RcnR to cobalt and FrmR to formaldehyde. However, in vitro all these sensors bind non-cognate metals, which alters DNA binding. We model the responses of these sensors to intracellular-buffered concentrations of Co(II) and Zn(II) based upon determined abundances, metal affinities and DNA affinities of each apo- and metalated sensor. The cognate sensors are modelled to respond at the lowest concentrations of their cognate metal, explaining specificity. However, other sensors are modelled to respond at concentrations only slightly higher, and cobalt or Zn(II) shock triggers mal-responses that match these predictions. Thus, perfect metal specificity is fine-tuned to a narrow range of buffered intracellular metal concentrations.
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Affiliation(s)
- Deenah Osman
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK.,Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Andrew W Foster
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK.,Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Junjun Chen
- Procter and Gamble, Mason Business Center, Cincinnati, OH, 45040, USA
| | - Kotryna Svedaite
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK.,Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | | | - Elena Lurie-Luke
- Procter and Gamble, Singapore Innovation Center, Singapore, 138589, Singapore
| | - Thomas G Huggins
- Procter and Gamble, Mason Business Center, Cincinnati, OH, 45040, USA
| | - Nigel J Robinson
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK. .,Department of Chemistry, Durham University, Durham, DH1 3LE, UK.
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12
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Foster AW, Pernil R, Patterson CJ, Scott AJP, Pålsson LO, Pal R, Cummins I, Chivers PT, Pohl E, Robinson NJ. A tight tunable range for Ni(II) sensing and buffering in cells. Nat Chem Biol 2017; 13:409-414. [PMID: 28166209 PMCID: PMC5365139 DOI: 10.1038/nchembio.2310] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/01/2016] [Indexed: 11/08/2022]
Abstract
The metal affinities of metal-sensing transcriptional regulators co-vary with cellular metal concentrations over more than 12 orders of magnitude. To understand the cause of this relationship, we determined the structure of the Ni(II) sensor InrS and then created cyanobacteria (Synechocystis PCC 6803) in which transcription of genes encoding a Ni(II) exporter and a Ni(II) importer were controlled by InrS variants with weaker Ni(II) affinities. Variant strains were sensitive to elevated nickel and contained more nickel, but the increase was small compared with the change in Ni(II) affinity. All of the variant sensors retained the allosteric mechanism that inhibits DNA binding following metal binding, but a response to nickel in vivo was observed only when the sensitivity was set to respond in a relatively narrow (less than two orders of magnitude) range of nickel concentrations. Thus, the Ni(II) affinity of InrS is attuned to cellular metal concentrations rather than the converse.
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Affiliation(s)
- Andrew W. Foster
- Department of Biosciences, Durham University, DH1 3LE, UK
- Department of Chemistry, Durham University, DH1 3LE, UK
| | - Rafael Pernil
- Department of Biosciences, Durham University, DH1 3LE, UK
- Department of Chemistry, Durham University, DH1 3LE, UK
| | - Carl J. Patterson
- Department of Biosciences, Durham University, DH1 3LE, UK
- Department of Chemistry, Durham University, DH1 3LE, UK
| | | | | | - Robert Pal
- Department of Chemistry, Durham University, DH1 3LE, UK
| | - Ian Cummins
- Department of Biosciences, Durham University, DH1 3LE, UK
| | - Peter T. Chivers
- Department of Biosciences, Durham University, DH1 3LE, UK
- Department of Chemistry, Durham University, DH1 3LE, UK
| | - Ehmke Pohl
- Department of Biosciences, Durham University, DH1 3LE, UK
- Department of Chemistry, Durham University, DH1 3LE, UK
| | - Nigel J. Robinson
- Department of Biosciences, Durham University, DH1 3LE, UK
- Department of Chemistry, Durham University, DH1 3LE, UK
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13
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Osman D, Piergentili C, Chen J, Sayer LN, Usón I, Huggins TG, Robinson NJ, Pohl E. The Effectors and Sensory Sites of Formaldehyde-responsive Regulator FrmR and Metal-sensing Variant. J Biol Chem 2016; 291:19502-16. [PMID: 27474740 PMCID: PMC5016687 DOI: 10.1074/jbc.m116.745174] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/21/2016] [Indexed: 11/29/2022] Open
Abstract
The DUF156 family of DNA-binding transcriptional regulators includes metal sensors that respond to cobalt and/or nickel (RcnR, InrS) or copper (CsoR) plus CstR, which responds to persulfide, and formaldehyde-responsive FrmR. Unexpectedly, the allosteric mechanism of FrmR from Salmonella enterica serovar Typhimurium is triggered by metals in vitro, and variant FrmR(E64H) gains responsiveness to Zn(II) and cobalt in vivo Here we establish that the allosteric mechanism of FrmR is triggered directly by formaldehyde in vitro Sensitivity to formaldehyde requires a cysteine (Cys(35) in FrmR) conserved in all DUF156 proteins. A crystal structure of metal- and formaldehyde-sensing FrmR(E64H) reveals that an FrmR-specific amino-terminal Pro(2) is proximal to Cys(35), and these residues form the deduced formaldehyde-sensing site. Evidence is presented that implies that residues spatially close to the conserved cysteine tune the sensitivities of DUF156 proteins above or below critical thresholds for different effectors, generating the semblance of specificity within cells. Relative to FrmR, RcnR is less responsive to formaldehyde in vitro, and RcnR does not sense formaldehyde in vivo, but reciprocal mutations FrmR(P2S) and RcnR(S2P), respectively, impair and enhance formaldehyde reactivity in vitro Formaldehyde detoxification by FrmA requires S-(hydroxymethyl)glutathione, yet glutathione inhibits formaldehyde detection by FrmR in vivo and in vitro Quantifying the number of FrmR molecules per cell and modeling formaldehyde modification as a function of [formaldehyde] demonstrates that FrmR reactivity is optimized such that FrmR is modified and frmRA is derepressed at lower [formaldehyde] than required to generate S-(hydroxymethyl)glutathione. Expression of FrmA is thereby coordinated with the accumulation of its substrate.
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Affiliation(s)
- Deenah Osman
- From the Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Cecilia Piergentili
- From the Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Junjun Chen
- Procter and Gamble, Mason Business Center, Cincinnati, Ohio 45040
| | | | - Isabel Usón
- the Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Barcelona Science Park, 08028 Barcelona, Spain, and the Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Thomas G Huggins
- Procter and Gamble, Mason Business Center, Cincinnati, Ohio 45040
| | - Nigel J Robinson
- From the Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom,
| | - Ehmke Pohl
- From the Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
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Robinson NJ, Dean RS, Cobb M, Brennan ML. Factors influencing common diagnoses made during first-opinion small-animal consultations in the United Kingdom. Prev Vet Med 2016; 131:87-94. [PMID: 27544257 DOI: 10.1016/j.prevetmed.2016.07.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 06/16/2016] [Accepted: 07/24/2016] [Indexed: 11/30/2022]
Abstract
It is currently unclear how frequently a diagnosis is made during small-animal consultations or how much of a role making a diagnosis plays in veterinary decision-making. Understanding more about the diagnostic process will help direct future research towards areas relevant to practicing veterinary surgeons. The aim of this study was to determine the frequency with which a diagnosis was made, classify the types of diagnosis made (and the factors influencing these) and determine which specific diagnoses were made for health problems discussed during small-animal consultations. Data were gathered during real-time direct observation of small-animal consultations in eight practices in the United Kingdom. Data collected included characteristics of the consultation (e.g. consultation type), patient (e.g. breed), and each problem discussed (e.g. new or pre-existing problem). Each problem discussed was classified into one of the following diagnosis types: definitive; working; presumed; open; previous. A three-level multivariable logistic-regression model was developed, with problem (Level 1) nested within patient (Level 2) nested within consulting veterinary surgeon (Level 3). Problems without a previous diagnosis, in cats and dogs only, were included in the model, which had a binary outcome variable of definitive diagnosis versus no definitive diagnosis. Data were recorded for 1901 animals presented, and data on diagnosis were gathered for 3192 health problems. Previous diagnoses were the most common diagnosis type (n=1116/3192; 35.0%), followed by open (n=868/3192; 27.2%) then definitive (n=660/3192; 20.7%). The variables remaining in the final model were patient age, problem history, consultation type, who raised the problem, and body system affected. New problems, problems in younger animals, and problems raised by the veterinary surgeon were more likely to result in a definitive diagnosis than pre-existing problems, problems in older animals, and problems raised by the owner. The most common diagnoses made were overweight/obese and periodontal disease (both n=210; 6.6%). Definitive diagnoses are rarely made during small-animal consultations, with much of the veterinary caseload involving management of ongoing problems or making decisions around new problems prior to a diagnosis being made. This needs to be taken into account when considering future research priorities, and it may be necessary to conduct research focused on the approach to common clinical presentations, rather than purely on the common diagnoses made. Examining how making a diagnosis affects the actions taken during the consultation may shed further light on the role of diagnosis in the clinical decision-making process.
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - M Cobb
- School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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Robinson NJ, Brennan ML, Cobb M, Dean RS. Investigating preventive-medicine consultations in first-opinion small-animal practice in the United Kingdom using direct observation. Prev Vet Med 2015; 124:69-77. [PMID: 26775818 DOI: 10.1016/j.prevetmed.2015.12.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 12/08/2015] [Accepted: 12/15/2015] [Indexed: 10/22/2022]
Abstract
Preventive-medicine consultations account for a large proportion of the veterinary caseload and previous research has suggested these consultations are fundamentally different from those in which the animal is presented for a specific health problem. There has been recent controversy around some aspects of preventive medicine for cats and dogs, and the full health benefits of the preventive-medicine consultation remain unclear. The aim of this study was to compare characteristics of the consultation and the problems discussed during the consultation between preventive-medicine consultations and other types of consultations. Data were gathered during direct observation of small-animal consultations in seven first-opinion practices in the United Kingdom. Data collected included type of clinical examination performed, patient signalment, and details of all problems discussed (including whether the problem was presenting or non-presenting, new or pre-existing, who had raised the problem, body system affected and whether an action was taken). A two-level multivariable logistic-regression model was developed, with canine and feline patients at Level 1 nested within consulting veterinary surgeons at Level 2, and a binary outcome variable of preventive-medicine consultation versus specific health-problem consultation. A total of 1807 patients were presented, of which 690 (38.2%) presented for a preventive-medicine consultation. Dogs were the most frequently presented species (n=1168; 64.6%) followed by cats (n=510; 28.2%), rabbits (n=86; 4.8%) and patients of other species (n=43; 2.4%). The five variables remaining in the multi-level model were whether multiple patients were presented, patient age, clinical examination type, weighing and number of problems discussed. Species, breed, sex, neutering status and practice did not remain in the final model. Many non-presenting problems, including both preventive-medicine problems and specific-health problems, were discussed and acted upon during all types of consultations. Dental and behavioural non-presenting problems were discussed more frequently during preventive-medicine consultations compared with specific health-problem consultations. Preventive-medicine consultations represent an opportunity for veterinary surgeons to discuss other aspects of preventive medicine, and to detect and manage new and ongoing health problems. A greater evidence base is needed to understand whether detecting and managing underlying disease during the preventive-medicine consultation has a positive impact on lifelong patient health and welfare.
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M Cobb
- School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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Rubio MÁ, Napolitano M, Ochoa de Alda JAG, Santamaría-Gómez J, Patterson CJ, Foster AW, Bru-Martínez R, Robinson NJ, Luque I. Trans-oligomerization of duplicated aminoacyl-tRNA synthetases maintains genetic code fidelity under stress. Nucleic Acids Res 2015; 43:9905-17. [PMID: 26464444 PMCID: PMC4787780 DOI: 10.1093/nar/gkv1020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/28/2015] [Indexed: 12/23/2022] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) play a key role in deciphering the genetic message by producing charged tRNAs and are equipped with proofreading mechanisms to ensure correct pairing of tRNAs with their cognate amino acid. Duplicated aaRSs are very frequent in Nature, with 25,913 cases observed in 26,837 genomes. The oligomeric nature of many aaRSs raises the question of how the functioning and oligomerization of duplicated enzymes is organized. We characterized this issue in a model prokaryotic organism that expresses two different threonyl-tRNA synthetases, responsible for Thr-tRNA(Thr) synthesis: one accurate and constitutively expressed (T1) and another (T2) with impaired proofreading activity that also generates mischarged Ser-tRNA(Thr). Low zinc promotes dissociation of dimeric T1 into monomers deprived of aminoacylation activity and simultaneous induction of T2, which is active for aminoacylation under low zinc. T2 either forms homodimers or heterodimerizes with T1 subunits that provide essential proofreading activity in trans. These findings evidence that in organisms with duplicated genes, cells can orchestrate the assemblage of aaRSs oligomers that meet the necessities of the cell in each situation. We propose that controlled oligomerization of duplicated aaRSs is an adaptive mechanism that can potentially be expanded to the plethora of organisms with duplicated oligomeric aaRSs.
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Affiliation(s)
- Miguel Ángel Rubio
- Instituto de Bioquímica Vegetal y Fotosíntesis, C.S.I.C. and Universidad de Sevilla, Avda Américo Vespucio 49, E-41092 Seville, Spain
| | - Mauro Napolitano
- Instituto de Bioquímica Vegetal y Fotosíntesis, C.S.I.C. and Universidad de Sevilla, Avda Américo Vespucio 49, E-41092 Seville, Spain
| | - Jesús A G Ochoa de Alda
- Facultad de Formación del Profesorado. Universidad de Extremadura, Avda de la Universidad s/n. E-10003, Cáceres, Spain
| | - Javier Santamaría-Gómez
- Instituto de Bioquímica Vegetal y Fotosíntesis, C.S.I.C. and Universidad de Sevilla, Avda Américo Vespucio 49, E-41092 Seville, Spain
| | | | | | - Roque Bru-Martínez
- Department of Agrochemistry and Biochemistry, Faculty of Science, University of Alicante, E-03080, Spain
| | | | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis, C.S.I.C. and Universidad de Sevilla, Avda Américo Vespucio 49, E-41092 Seville, Spain
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Osman D, Piergentili C, Chen J, Chakrabarti B, Foster AW, Lurie-Luke E, Huggins TG, Robinson NJ. Generating a Metal-responsive Transcriptional Regulator to Test What Confers Metal Sensing in Cells. J Biol Chem 2015; 290:19806-22. [PMID: 26109070 PMCID: PMC4528141 DOI: 10.1074/jbc.m115.663427] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Indexed: 11/06/2022] Open
Abstract
FrmR from Salmonella enterica serovar typhimurium (a CsoR/RcnR-like transcriptional de-repressor) is shown to repress the frmRA operator-promoter, and repression is alleviated by formaldehyde but not manganese, iron, cobalt, nickel, copper, or Zn(II) within cells. In contrast, repression by a mutant FrmRE64H (which gains an RcnR metal ligand) is alleviated by cobalt and Zn(II). Unexpectedly, FrmR was found to already bind Co(II), Zn(II), and Cu(I), and moreover metals, as well as formaldehyde, trigger an allosteric response that weakens DNA affinity. However, the sensory metal sites of the cells' endogenous metal sensors (RcnR, ZntR, Zur, and CueR) are all tighter than FrmR for their cognate metals. Furthermore, the endogenous metal sensors are shown to out-compete FrmR. The metal-sensing FrmRE64H mutant has tighter metal affinities than FrmR by approximately 1 order of magnitude. Gain of cobalt sensing by FrmRE64H remains enigmatic because the cobalt affinity of FrmRE64H is substantially weaker than that of the endogenous cobalt sensor. Cobalt sensing requires glutathione, which may assist cobalt access, conferring a kinetic advantage. For Zn(II), the metal affinity of FrmRE64H approaches the metal affinities of cognate Zn(II) sensors. Counter-intuitively, the allosteric coupling free energy for Zn(II) is smaller in metal-sensing FrmRE64H compared with nonsensing FrmR. By determining the copies of FrmR and FrmRE64H tetramers per cell, then estimating promoter occupancy as a function of intracellular Zn(II) concentration, we show how a modest tightening of Zn(II) affinity, plus weakened DNA affinity of the apoprotein, conspires to make the relative properties of FrmRE64H (compared with ZntR and Zur) sufficient to sense Zn(II) inside cells.
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Affiliation(s)
- Deenah Osman
- From the School of Biological and Biomedical Sciences and Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Cecilia Piergentili
- From the School of Biological and Biomedical Sciences and Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Junjun Chen
- Procter and Gamble, Mason Business Centre, Cincinnati, Ohio 45040, and
| | - Buddhapriya Chakrabarti
- From the School of Biological and Biomedical Sciences and Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Andrew W Foster
- From the School of Biological and Biomedical Sciences and Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Elena Lurie-Luke
- Life Sciences Open Innovation, London Innovation Centre, Procter and Gamble Technical Centres, Ltd., Egham TW20 9NW, United Kingdom
| | - Thomas G Huggins
- Procter and Gamble, Mason Business Centre, Cincinnati, Ohio 45040, and
| | - Nigel J Robinson
- From the School of Biological and Biomedical Sciences and Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom,
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Robinson NJ, Dean RS, Cobb M, Brennan ML. Investigating common clinical presentations in first opinion small animal consultations using direct observation. Vet Rec 2015; 176:463. [PMID: 25564472 PMCID: PMC4431344 DOI: 10.1136/vr.102751] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2014] [Indexed: 11/30/2022]
Abstract
Understanding more about the clinical presentations encountered in veterinary practice is vital in directing research towards areas relevant to practitioners. The aim of this study was to describe all problems discussed during a convenience sample of consultations using a direct observation method. A data collection tool was used to gather data by direct observation during small animal consultations at eight sentinel practices. Data were recorded for all presenting and non-presenting specific health problems discussed. A total of 1901 patients were presented with 3206 specific health problems discussed. Clinical presentation varied widely between species and between presenting and non-presenting problems. Skin lump, vomiting and inappetence were the most common clinical signs reported by the owner while overweight/obese, dental tartar and skin lump were the most common clinical examination findings. Skin was the most frequently affected body system overall followed by non-specific problems then the gastrointestinal system. Consultations are complex, with a diverse range of different clinical presentations seen. Considering the presenting problem only may give an inaccurate view of the veterinary caseload, as some common problems are rarely the reason for presentation. Understanding the common diagnoses made is the next step and will help to further focus questions for future research.
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M Cobb
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M Cobb
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M Cobb
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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Abstract
The metal binding preferences of most metalloproteins do not match their metal requirements. Thus, metallation of an estimated 30% of metalloenzymes is aided by metal delivery systems, with ∼ 25% acquiring preassembled metal cofactors. The remaining ∼ 70% are presumed to compete for metals from buffered metal pools. Metallation is further aided by maintaining the relative concentrations of these pools as an inverse function of the stabilities of the respective metal complexes. For example, magnesium enzymes always prefer to bind zinc, and these metals dominate the metalloenzymes without metal delivery systems. Therefore, the buffered concentration of zinc is held at least a million-fold below magnesium inside most cells.
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Affiliation(s)
- Andrew W Foster
- From the Department of Chemistry and School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Deenah Osman
- From the Department of Chemistry and School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Nigel J Robinson
- From the Department of Chemistry and School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M Cobb
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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Abstract
Various different methods are currently being used to capture data from small animal consultations. The aim of this study was to develop a tool to record detailed data from consultations by direct observation. A second aim was to investigate the complexity of the consultation by examining the number of problems discussed per patient. A data collection tool was developed and used during direct observation of small animal consultations in eight practices. Data were recorded on consultation type, patient signalment and number of problems discussed. During 16 weeks of data collection, 1901 patients were presented. Up to eight problems were discussed for some patients; more problems were discussed during preventive medicine consultations than during first consultations (P<0.001) or revisits (P<0.001). Fewer problems were discussed for rabbits than cats (P<0.001) or dogs (P<0.001). Age was positively correlated with discussion of specific health problems and negatively correlated with discussion of preventive medicine. Consultations are complex with multiple problems frequently discussed, suggesting comorbidity may be common. Future research utilising practice data should consider how much of this complexity needs to be captured, and use appropriate methods accordingly. The findings here have implications for directing research and education as well as application in veterinary practice.
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Affiliation(s)
- N J Robinson
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - M Cobb
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - R S Dean
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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Foster AW, Dainty SJ, Patterson CJ, Pohl E, Blackburn H, Wilson C, Hess CR, Rutherford JC, Quaranta L, Corran A, Robinson NJ. A chemical potentiator of copper-accumulation used to investigate the iron-regulons of Saccharomyces cerevisiae. Mol Microbiol 2014; 93:317-30. [PMID: 24895027 PMCID: PMC4149784 DOI: 10.1111/mmi.12661] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2014] [Indexed: 12/29/2022]
Abstract
The extreme resistance of Saccharomyces cerevisiae to copper is overcome by 2-(6-benzyl-2-pyridyl)quinazoline (BPQ), providing a chemical-biology tool which has been exploited in two lines of discovery. First, BPQ is shown to form a red (BPQ)2Cu(I) complex and promote Ctr1-independent copper-accumulation in whole cells and in mitochondria isolated from treated cells. Multiple phenotypes, including loss of aconitase activity, are consistent with copper-BPQ mediated damage to mitochondrial iron–sulphur clusters. Thus, a biochemical basis of copper-toxicity in S. cerevisiae is analogous to other organisms. Second, iron regulons controlled by Aft1/2, Cth2 and Yap5 that respond to mitochondrial iron–sulphur cluster status are modulated by copper-BPQ causing iron hyper-accumulation via upregulated iron-import. Comparison of copper-BPQ treated, untreated and copper-only treated wild-type and fra2Δ by RNA-seq has uncovered a new candidate Aft1 target-gene (LSO1) and paralogous non-target (LSO2), plus nine putative Cth2 target-transcripts. Two lines of evidence confirm that Fra2 dominates basal repression of the Aft1/2 regulons in iron-replete cultures. Fra2-independent control of these regulons is also observed but CTH2 itself appears to be atypically Fra2-dependent. However, control of Cth2-target transcripts which is independent of CTH2 transcript abundance or of Fra2, is also quantified. Use of copper-BPQ supports a substantial contribution of metabolite repression to iron-regulation.
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Affiliation(s)
- Andrew W Foster
- Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham, DH1 3LE, UK
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Robinson NJ, Valentine SE, Tomillo PS, Saba VS, Spotila JR, Paladino FV. Multidecadal trends in the nesting phenology of Pacific and Atlantic leatherback turtles are associated with population demography. ENDANGER SPECIES RES 2014. [DOI: 10.3354/esr00604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Foster AW, Pernil R, Patterson CJ, Robinson NJ. Metal specificity of cyanobacterial nickel-responsive repressor InrS: cells maintain zinc and copper below the detection threshold for InrS. Mol Microbiol 2014; 92:797-812. [PMID: 24666373 PMCID: PMC4235346 DOI: 10.1111/mmi.12594] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2014] [Indexed: 12/25/2022]
Abstract
InrS is a Ni(II)-responsive, CsoR/RcnR-like, DNA-binding transcriptional repressor of the nrsD gene, but the Ni(II) co-ordination sphere of InrS is unlike Ni(II)-RcnR. We show that copper and Zn(II) also bind tightly to InrS and in vitro these ions also impair InrS binding to the nrsD operator-promoter. InrS does not respond to Zn(II) (or copper) in vivo after 48 h, when Zn(II) sensor ZiaR responds, but InrS transiently responds (1 h) to both metals. InrS conserves only one (of two) second co-ordination shell residues of CsoR (Glu98 in InrS). The allosteric mechanism of InrS is distinct from Cu(I)-CsoR and conservation of deduced second shell residues better predicts metal specificity than do the metal ligands. The allosteric mechanism of InrS permits greater promiscuity in vitro than CsoR. The factors dictating metal-selectivity in vivo are that KNi(II) and ΔGCNi(II)-InrS·DNA are sufficiently high, relative to other metal sensors, for InrS to detect Ni(II), while the equivalent parameters for copper may be insufficient for copper-sensing in S ynechocystis (at 48 h). InrS KZn(II) (5.6 × 10−13 M) is comparable to the sensory sites of ZiaR (and Zur), but ΔGCZn(II)-InrS·DNA is less than ΔGCZn(II)-ZiaR·DNA implying that relative to other sensors, ΔGCZn(II)-Sensor·DNA rather than KZn(II) determines the final detection threshold for Zn(II).
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Affiliation(s)
- Andrew W Foster
- Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham, DH1 3LE, UK
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Prieto-Alhambra D, Petri H, Goldenberg JSB, Khong TP, Klungel OH, Robinson NJ, de Vries F. Excess risk of hip fractures attributable to the use of antidepressants in five European countries and the USA. Osteoporos Int 2014; 25:847-55. [PMID: 24448776 DOI: 10.1007/s00198-013-2612-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 12/17/2013] [Indexed: 11/30/2022]
Abstract
SUMMARY The association between antidepressant use and hip fracture remains unclear. We conducted a systematic review to estimate Population Attributable Risks (PAR) for France, Germany, Italy, Spain, UK, and the USA. We report a heterogeneous prevalence of antidepressant use and related PARs, both lowest for Italy and highest for the USA. INTRODUCTION Antidepressant use has been associated with an increased hip fracture risk in observational studies. However, the potential contribution of antidepressant consumption on the population rate of hip fractures has not been described. Our aim was to estimate the impact of the use of different classes of antidepressants on the rate of hip fracture at a population-level in France, Germany, Italy, Spain, the UK, and the USA. METHODS We conducted a systematic literature review to estimate the pooled relative risk (RR) of hip fracture according to use of antidepressants. Prevalence rates of antidepressant use (Pe) in 2009 were calculated for each country using the The Intercontinental Medical Statistics database and three public databases from Denmark, the Netherlands, and Norway. Both the RR and Pe were used to calculate PAR of hip fractures associated with antidepressant use. RESULTS The literature review showed an increased risk of hip fractures in antidepressant users (RR, 1.7; 95 % confidence interval (CI), 1.5-2.0). Rates of antidepressant use showed considerable differences between countries, ranging from 4.4 % (Italy) to 11.2 % (USA) in the year 2009. The estimated PAR of antidepressants on hip fracture rates were 3.0 % (95 % CI, 2.0-4.1; Italy), 3.1 % (95 % CI, 2.1-4.3; Germany), 3.8 % (95 % CI, 2.6-5.3; France), 4.8 % (95 % CI, 3.3-6.5; Spain), 4.9 % (95 % CI, 3.4-6.8; UK), and 7.2 % (95 % CI, 5.0-9.9; USA). PARs differed for different types of antidepressants, with highest attributable risks for selective serotonin reuptake inhibitors. CONCLUSIONS These findings suggest that the potential contribution of antidepressant use to the population rate of hip fractures in the five large EU countries and the USA varies between 3 and 7 %.
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Affiliation(s)
- D Prieto-Alhambra
- Oxford National Institute for Health and Research (NIHR) Musculoskeletal Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
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Nielsen TD, Dean RS, Robinson NJ, Massey A, Brennan ML. Survey of the UK veterinary profession: common species and conditions nominated by veterinarians in practice. Vet Rec 2014; 174:324. [PMID: 24570401 PMCID: PMC3995283 DOI: 10.1136/vr.101745] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The practice of evidence-based veterinary medicine involves the utilisation of scientific evidence for clinical decision making. To enable this, research topics pertinent to clinical practice need to be identified, and veterinary clinicians are best placed to do this. The main aim of this study was to describe the veterinary population, the common species and conditions veterinary clinicians nominated they saw in practice and how much information clinicians perceived was available in the literature for these. A questionnaire was distributed to all Royal College of Veterinary Surgeons registered veterinarians agreeing to be contacted for research purposes (n=14,532). A useable response rate of 33 per cent (4842/14,532) was achieved. The most commonly seen species reported by vets were dogs, cats and rabbits followed by equines and cattle. Overall, skin conditions were most commonly mentioned for small animals, musculoskeletal conditions for equines and reproduction conditions for production animals. Veterinary clinicians perceived there was a higher level of information available in the literature for conditions in dogs, cattle and equines and lower levels for rabbits and guinea pigs. The results from this study can be used to help define the research needs of the profession to aid the incorporation of evidence in veterinary practice.
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Affiliation(s)
- T D Nielsen
- Centre for Evidence-based Veterinary Medicine, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
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Patterson CJ, Pernil R, Dainty SJ, Chakrabarti B, Henry CE, Money VA, Foster AW, Robinson NJ. Co(ll)-detection does not follow Kco(ll) gradient: channelling in Co(ll)-sensing. Metallomics 2013; 5:352-62. [PMID: 23420021 DOI: 10.1039/c3mt20241k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The MerR-like transcriptional activator CoaR detects surplus Co(ll) to regulate Co(ll) efflux in a cyanobacterium. This organism also has cytosolic metal-sensors from three further families represented by Zn(ll)-sensors ZiaR and Zur plus Ni(ll)-sensor InrS. Here we discover by competition with Fura-2 that CoaR has KCo(ll) weaker than 7 × 10(-8) M, which is weaker than ZiaR, Zur and InrS (KCo(ll) = 6.94 ± 1.3 × 10(-10) M; 4.56 ± 0.16 × 10(-10) M; and 7.69 ± 1.1 × 10(-9) M respectively). KCo(ll) for CoaR is also weak in the CoaR-DNA adduct. Further, Co(ll) promotes DNA-dissociation by ZiaR and DNA-association by Zur in vitro in a manner analogous to Zn(ll), as monitored by fluorescence anisotropy. After 48 h exposure to maximum non-inhibitory [Co(ll)], CoaR responds in vivo yet the two Zn(ll)-sensors do not, despite their tighter KCo(ll) and despite Co(ll) triggering allostery in ZiaR and Zur in vitro. These data imply that the two Zn(ll) sensors fail to respond because they fail to gain access to Co(ll) under these conditions in vivo. Several lines of evidence suggest that CoaR is membrane associated via a domain with sequence similarity to precorrin isomerase, an enzyme of vitamin B12 biosynthesis. Moreover, site directed mutagenesis reveals that transcriptional activation requires CoaR residues that are predicted to form hydrogen bonds to a tetrapyrrole. The Co(ll)-requiring vitamin B12 biosynthetic pathway is also membrane associated suggesting putative mechanisms by which Co(ll)-containing tetrapyrroles and/or Co(ll) ions are channelled to CoaR.
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Affiliation(s)
- Carl J Patterson
- School/Department of Biological and Biomedical Sciences, Biophysical Sciences Institute, Durham University, DH1 3LE, UK
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Osman D, Patterson CJ, Bailey K, Fisher K, Robinson NJ, Rigby SEJ, Cavet JS. The copper supply pathway to aSalmonellaCu,Zn-superoxide dismutase (SodCII) involves P1B-type ATPase copper efflux and periplasmic CueP. Mol Microbiol 2012; 87:466-77. [DOI: 10.1111/mmi.12107] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2012] [Indexed: 11/26/2022]
Affiliation(s)
- Deenah Osman
- Life Sciences; Michael Smith Building; University of Manchester; Manchester; M13 9PT; UK
| | - Carl J. Patterson
- The Biophysical Sciences Institute; Department of Chemistry; School of Biological and Biomedical Sciences; University of Durham; Durham; DH1 3LE; UK
| | - Kathryn Bailey
- Life Sciences; Michael Smith Building; University of Manchester; Manchester; M13 9PT; UK
| | - Karl Fisher
- Life Sciences; Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street; Manchester; M1 7DN; UK
| | - Nigel J. Robinson
- The Biophysical Sciences Institute; Department of Chemistry; School of Biological and Biomedical Sciences; University of Durham; Durham; DH1 3LE; UK
| | - Stephen E. J. Rigby
- Life Sciences; Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street; Manchester; M1 7DN; UK
| | - Jennifer S. Cavet
- Life Sciences; Michael Smith Building; University of Manchester; Manchester; M13 9PT; UK
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Foster AW, Patterson CJ, Pernil R, Hess CR, Robinson NJ. Cytosolic Ni(II) sensor in cyanobacterium: nickel detection follows nickel affinity across four families of metal sensors. J Biol Chem 2012; 287:12142-51. [PMID: 22356910 PMCID: PMC3320959 DOI: 10.1074/jbc.m111.338301] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Efflux of surplus Ni(II) across the outer and inner membranes of Synechocystis PCC 6803 is mediated by the Nrs system under the control of a sensor of periplasmic Ni(II), NrsS. Here, we show that the product of ORF sll0176, which encodes a CsoR/RcnR-like protein now designated InrS (for internal nickel-responsive sensor), represses nrsD (NrsD is deduced to efflux Ni(II) across the inner membrane) from a cryptic promoter between the final two ORFs in the nrs operon. Transcripts initiated from the newly identified nrsD promoter accumulate in response to nickel or cobalt but not copper, and recombinant InrS forms specific, Ni(II)-inhibited complexes with the nrsD promoter region. Metal-dependent difference spectra of Ni(II)- and Cu(I)-InrS are similar to Cu(I)-sensing CsoR and dissimilar to Ni(II)/Co(II)-sensing RcnR, consistent with factors beyond the primary coordination sphere switching metal selectivity. Competition with chelators mag-fura-2, nitrilotriacetic acid, EDTA, and EGTA estimate KD Ni(II) for the tightest site of InrS as 2.05 (±1.5) × 10−14m, and weaker KD Ni(II) for the cells' metal sensors of other types: Zn(II) co-repressor Zur, Co(II) activator CoaR, and Zn(II) derepressor ZiaR. Ni(II) transfer to InrS occurs upon addition to Ni(II) forms of each other sensor. InrS binds Ni(II) sufficiently tightly to derepress Ni(II) export at concentrations below KD Ni(II) of the other sensors.
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Affiliation(s)
- Andrew W Foster
- Biophysical Sciences Institute, Department of Chemistry, School of Biological and Biomedical Sciences, University of Durham, Durham DH1 3LE, United Kingdom
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Affiliation(s)
- Nigel J Robinson
- Biophysical Sciences Institute, Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, UK.
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Abstract
Metalloproteins are essential for many cellular functions, but it has not been clear how they distinguish between the different metals to bind the correct ones. A report in BMC Biology finds that preferences of two metallothionein isoforms for two different cations are due to inherent properties of these usually less discriminating proteins. Here these observations are discussed in the context of the cellular mechanisms that regulate metal binding to proteins. See research article: http://www.biomedcentral.com/1741-7007/9/4
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Affiliation(s)
- Andrew W Foster
- Biophysical Sciences Institute, Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, DH1 3LE, UK.
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Paynter JJ, Andres-Enguix I, Fowler PW, Tottey S, Cheng W, Enkvetchakul D, Bavro VN, Kusakabe Y, Sansom MSP, Robinson NJ, Nichols CG, Tucker SJ. Functional complementation and genetic deletion studies of KirBac channels: activatory mutations highlight gating-sensitive domains. J Biol Chem 2010; 285:40754-61. [PMID: 20876570 PMCID: PMC3003375 DOI: 10.1074/jbc.m110.175687] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 09/27/2010] [Indexed: 12/16/2022] Open
Abstract
The superfamily of prokaryotic inwardly rectifying (KirBac) potassium channels is homologous to mammalian Kir channels. However, relatively little is known about their regulation or about their physiological role in vivo. In this study, we have used random mutagenesis and genetic complementation in K(+)-auxotrophic Escherichia coli and Saccharomyces cerevisiae to identify activatory mutations in a range of different KirBac channels. We also show that the KirBac6.1 gene (slr5078) is necessary for normal growth of the cyanobacterium Synechocystis PCC6803. Functional analysis and molecular dynamics simulations of selected activatory mutations identified regions within the slide helix, transmembrane helices, and C terminus that function as important regulators of KirBac channel activity, as well as a region close to the selectivity filter of KirBac3.1 that may have an effect on gating. In particular, the mutations identified in TM2 favor a model of KirBac channel gating in which opening of the pore at the helix-bundle crossing plays a far more important role than has recently been proposed.
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Affiliation(s)
| | | | - Philip W. Fowler
- the Structural Bioinformatics and Computational Biochemistry Unit, Department of Biochemistry
| | - Stephen Tottey
- the Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle NE1 7RU, United Kingdom
| | - Wayland Cheng
- the OXION Initiative, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Decha Enkvetchakul
- the Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104, and
| | | | | | - Mark S. P. Sansom
- the Structural Bioinformatics and Computational Biochemistry Unit, Department of Biochemistry
- the OXION Initiative, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Nigel J. Robinson
- the Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle NE1 7RU, United Kingdom
| | - Colin G. Nichols
- the Department of Cell Biology and Physiology, and Center for Investigation of Membrane Excitability Disorders, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Stephen J. Tucker
- the Department of Physics, Clarendon Laboratory, and
- the OXION Initiative, University of Oxford, Oxford OX1 3PU, United Kingdom
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Waldron KJ, Firbank SJ, Dainty SJ, Pérez-Rama M, Tottey S, Robinson NJ. Structure and metal loading of a soluble periplasm cuproprotein. J Biol Chem 2010; 285:32504-11. [PMID: 20702411 DOI: 10.1074/jbc.m110.153080] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A copper-trafficking pathway was found to enable Cu(2+) occupancy of a soluble periplasm protein, CucA, even when competing Zn(2+) is abundant in the periplasm. Here, we solved the structure of CucA (a new cupin) and found that binding of Cu(2+), but not Zn(2+), quenches the fluorescence of Trp(165), which is adjacent to the metal site. Using this fluorescence probe, we established that CucA becomes partly occupied by Zn(2+) following exposure to equimolar Zn(2+) and Cu(2+). Cu(2+)-CucA is more thermodynamically stable than Zn(2+)-CucA but k((Zn→Cu)exchange) is slow, raising questions about how the periplasm contains solely the Cu(2+) form. We discovered that a copper-trafficking pathway involving two copper transporters (CtaA and PacS) and a metallochaperone (Atx1) is obligatory for Cu(2+)-CucA to accumulate in the periplasm. There was negligible CucA protein in the periplasm of ΔctaA cells, but the abundance of cucA transcripts was unaltered. Crucially, ΔctaA cells overaccumulate low M(r) copper complexes in the periplasm, and purified apoCucA can readily acquire Cu(2+) from ΔctaA periplasm extracts, but in vivo apoCucA fails to come into contact with these periplasmic copper pools. Instead, copper traffics via a cytoplasmic pathway that is coupled to CucA translocation to the periplasm.
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Affiliation(s)
- Kevin J Waldron
- Institute for Cell and Molecular Biosciences, University of Newcastle Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
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39
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Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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Osman D, Waldron KJ, Denton H, Taylor CM, Grant AJ, Mastroeni P, Robinson NJ, Cavet JS. Copper homeostasis in Salmonella is atypical and copper-CueP is a major periplasmic metal complex. J Biol Chem 2010; 285:25259-68. [PMID: 20534583 PMCID: PMC2919089 DOI: 10.1074/jbc.m110.145953] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Salmonella enterica sv. typhimurium (S. enterica sv. Typhimurium) has two metal-transporting P(1)-type ATPases whose actions largely overlap with respect to growth in elevated copper. Mutants lacking both ATPases over-accumulate copper relative to wild-type or either single mutant. Such duplication of ATPases is unusual in bacterial copper tolerance. Both ATPases are under the control of MerR family metal-responsive transcriptional activators. Analyses of periplasmic copper complexes identified copper-CueP as one of the predominant metal pools. Expression of cueP was recently shown to be controlled by the same metal-responsive activator as one of the P(1)-type ATPase genes (copA), and copper-CueP is a further atypical feature of copper homeostasis in S. enterica sv. Typhimurium. Elevated copper is detected by a reporter construct driven by the promoter of copA in wild-type S. enterica sv. Typhimurium during infection of macrophages. Double mutants missing both ATPases also show reduced survival inside cultured macrophages. It is hypothesized that elevated copper within macrophages may have selected for specialized copper-resistance systems in pathogenic microorganism such as S. enterica sv. Typhimurium.
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Affiliation(s)
- Deenah Osman
- Life Sciences, Michael Smith Building, University of Manchester, United Kingdom
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41
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Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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42
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Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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Abstract
Almost half of all enzymes must associate with a particular metal to function. An ambition is to understand why each metal-protein partnership arose and how it is maintained. Metal availability provides part of the explanation, and has changed over geological time and varies between habitats but is held within vital limits in cells. Such homeostasis needs metal sensors, and there is an ongoing search to discover the metal-sensing mechanisms. For metalloproteins to acquire the right metals, metal sensors must correctly distinguish between the inorganic elements.
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Affiliation(s)
- Kevin J Waldron
- Cell & Molecular Biosciences, Medical School, Newcastle University, Newcastle NE2 4HH, UK
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Banci L, Bertini I, Ciofi-Baffoni S, Poggi L, Vanarotti M, Tottey S, Waldron KJ, Robinson NJ. NMR structural analysis of the soluble domain of ZiaA-ATPase and the basis of selective interactions with copper metallochaperone Atx1. J Biol Inorg Chem 2009; 15:87-98. [DOI: 10.1007/s00775-009-0568-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 06/29/2009] [Indexed: 10/20/2022]
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Dainty SJ, Patterson CJ, Waldron KJ, Robinson NJ. Interaction between cyanobacterial copper chaperone Atx1 and zinc homeostasis. J Biol Inorg Chem 2009; 15:77-85. [PMID: 19543924 DOI: 10.1007/s00775-009-0555-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Accepted: 06/05/2009] [Indexed: 11/26/2022]
Abstract
Cyanobacterial Atx1 is a copper chaperone which interacts with two copper-transporting ATPases to assist copper supply to plastocyanin and cytochrome oxidase. ZiaA is a Zn(2+)-exporting ATPase and ziaA expression is regulated by ZiaR. Here we show that gene expression from the ziaA operator promoter, monitored using reverse transcriptase PCR and lacZ fusions, is elevated in Deltaatx1 mutants. Although Cu(+) tightly binds recombinant ZiaR in vitro, Cu(+) is less effective at dissociating ZiaR-DNA complexes than Zn(2+) and crucially ziaA expression responds to Zn(2+) but not copper in both wild-type and Deltaatx1 cells. Consistent with enhanced expression of ZiaA, Deltaatx1 cells have slightly elevated Zn(2+) resistance. Recombinant Zn(2+)-Atx1 is recovered from Zn(2+)-supplemented Escherichia coli and even after copper supplementation substantial amounts of Zn(2+)-Atx1 are isolated. Taken together, these data suggest that Zn(2+)-Atx1 can form in vivo.
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Affiliation(s)
- Samantha J Dainty
- Institute for Cell and Molecular Bioscience, Newcastle University, UK
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Cowan FM, Pascoe SJ, Barlow KL, Langhaug LF, Jaffar S, Hargrove JW, Robinson NJ, Bassett MT, Wilson D, Brown DWG, Hayes RJ. A randomised placebo-controlled trial to explore the effect of suppressive therapy with acyclovir on genital shedding of HIV-1 and herpes simplex virus type 2 among Zimbabwean sex workers. Sex Transm Infect 2008; 84:548-53. [DOI: 10.1136/sti.2008.031153] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Newcastle University Medical School, Framlington Place, Newcastle NE24HH, UK.
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Tottey S, Waldron KJ, Firbank SJ, Reale B, Bessant C, Sato K, Cheek TR, Gray J, Banfield MJ, Dennison C, Robinson NJ. Protein-folding location can regulate manganese-binding versus copper- or zinc-binding. Nature 2008; 455:1138-42. [DOI: 10.1038/nature07340] [Citation(s) in RCA: 253] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 08/13/2008] [Indexed: 01/22/2023]
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Feudjo-Tepie MA, Robinson NJ, Bennett D. Prevalence of diagnosed chronic immune thrombocytopenic purpura in the US: analysis of a large US claim database: a rebuttal. J Thromb Haemost 2008; 6:711-2; author reply 713. [PMID: 18221355 DOI: 10.1111/j.1538-7836.2008.02911.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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