title: AtSIA1 AND AtOSA1: two Abc1 proteins involved in oxidative stress responses and iron distribution within chloroplasts.
abstract: The Abc1 protein kinases are a large family of functionally diverse proteins with multiple roles in the regulation of respiration and oxidative stress tolerance. A functional characterization was carried out for AtSIA1, an Arabidopsis thaliana Abc1-like protein, focusing on its potential redundancy with its homolog AtOSA1. Both proteins are located within chloroplasts, even if a different subplastidial localization seems probable. The comparison of atsia1 and atosa1 mutants, atsia1/atosa1 double mutant and wild-type plants revealed a reduction in plastidial iron-containing proteins of the Cytb6 f complex in the mutants. Iron uptake from soil is not hampered in mutant lines, suggesting that AtSIA1 and AtOSA1 affect iron distribution within the chloroplast. Mutants accumulated more ferritin and superoxide, and showed reduced tolerance to reactive oxygen species (ROS), potentially indicating a basal role in oxidative stress. The mutants produced higher concentrations of plastochromanol and plastoquinones than wild-type plants, but only atsia1 plants developed larger plastoglobules and contained higher concentrations of α- and γ-tocopherol and VTE1. Taken together, these data suggest that AtSIA1 and AtOSA1 probably act in signaling pathways that influence responses to ROS production and oxidative stress.
authors.affiliation: Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada Le Grazie 15, Verona, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Manara
authors.affiliation: Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada Le Grazie 15, Verona, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: DalCorso
authors.affiliation: Dept Biologie I, Botanik, Biozentrum der LMU München, Großhaderner Str. 2-4, Planegg-Martinsried, Germany.
authors.forename: Dario
authors.initials: D
authors.lastname: Leister
authors.affiliation: Heinrich-Heine-Universität Biochemie der Pflanzen, Universitätsstraße 1, Düsseldorf, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Jahns
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Padova, Via Ugo Bassi, 58/B, Padova, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Baldan
authors.affiliation: Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada Le Grazie 15, Verona, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Furini
mesh_terms: D064286:ATP Binding Cassette Transporter 1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002736:Chloroplasts / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D009154:Mutation; D018384:Oxidative Stress; D010788:Photosynthesis; D010802:Phylogeny; D020539:Sequence Analysis, Protein; D013312:Stress, Physiological
chemical_list: D064286:ATP Binding Cassette Transporter 1; D029681:Arabidopsis Proteins; C000603464:OSA1 protein, Arabidopsis; C000603463:SIA1 protein, Arabidopsis; D007501:Iron
keywords: Abc1 protein; AtOSA1; AtSIA1; oxidative stress; plastoglobules