title: Zur (FurB) is a key factor in the control of the oxidative stress response in Anabaena sp. PCC 7120.
abstract: Iron and zinc are necessary nutrients whose homeostasis is tightly controlled by members of the ferric uptake regulator (FUR) superfamily in the cyanobacterium Anabaena sp. PCC7120. Although the link between iron metabolism and oxidative stress management is well documented, little is known about the connection between zinc homeostasis and the oxidative stress response in cyanobacteria. Zinc homeostasis in Anabaena is controlled by Zur, also named FurB. When overexpressed in Escherichia coli, Zur (FurB) improved cell survival during oxidative stress. In order to investigate the possible correlation between Zur and the oxidative stress response in Anabaena, zur deletion and zur-overexpressing strains have been constructed, and the consequences of Zur imbalance evaluated. The lack of Zur increased sensitivity to hydrogen peroxide (H2 O2 ), whereas an excess of Zur enhanced oxidative stress resistance. Both mutants displayed pleiotropic phenotypes, including alterations on the filament surfaces observable by scanning electron microscopy, reduced content of endogenous H2 O2 and altered expression of sodA, catalases and several peroxiredoxins. Transcriptional and biochemical analyses unveiled that the appropriate level of Zur is required for proper control of the oxidative stress response and allowed us to identify major antioxidant enzymes as novel members of the Zur regulon.
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Instituto de Biocomputación y Física de Sistemas Complejos, Universidad de Zaragoza, Zaragoza, 50009, Spain.
authors.forename: Violeta C
authors.initials: VC
authors.lastname: Sein-Echaluce
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Instituto de Biocomputación y Física de Sistemas Complejos, Universidad de Zaragoza, Zaragoza, 50009, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: González
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Sevilla, E-41092, Spain.
authors.forename: Mauro
authors.initials: M
authors.lastname: Napolitano
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Sevilla, E-41092, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Luque
authors.affiliation: Microbiology Unit, Botany and Plant Biology Department, University of Geneva, Ch. Des Embrouchis 10, Jussy-Geneva, CH-1254, Switzerland.
authors.forename: Francisco
authors.initials: F
authors.lastname: Barja
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Instituto de Biocomputación y Física de Sistemas Complejos, Universidad de Zaragoza, Zaragoza, 50009, Spain.
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Peleato
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Instituto de Biocomputación y Física de Sistemas Complejos, Universidad de Zaragoza, Zaragoza, 50009, Spain.
authors.forename: María F
authors.initials: MF
authors.lastname: Fillat
mesh_terms: D017033:Anabaena / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000235:genetics / Q000502:physiology*; D054464:Peroxiredoxins / Q000378:metabolism; D018085:Regulon; D013482:Superoxide Dismutase / Q000378:metabolism; D015032:Zinc / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D006861:Hydrogen Peroxide; D007501:Iron; D054464:Peroxiredoxins; D002374:Catalase; C095500:SodA protein, Bacteria; D013482:Superoxide Dismutase; D015032:Zinc