title: Localization of a putative ClC chloride channel in spinach chloroplasts.
abstract: Seven genes seem to encode for putative ClC chloride channels (AtClC-a to AtClC-g) in Arabidopsis thaliana. Their function and localization is still largely unknown. AtClC-f shares considerable sequence similarity with putative ClC channel proteins from Synechocystis, considered to represent the precursor of chloroplasts. We show by biochemical and mass spectrometry analysis that ClC-f is located in the outer envelope membrane of spinach chloroplasts. Consistent with the plastidial localization of ClC-f, p-chlorophenoxy-acetic acid (CPA) reduces photosynthetic activity and the protein is expressed in etioplasts and chloroplasts but not in root tissue. These findings may represent a step toward the molecular identification of ion channel activities in chloroplast membranes.
authors.affiliation: Department of Biology, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Teardo
authors.forename: Erica
authors.initials: E
authors.lastname: Frare
authors.forename: Anna
authors.initials: A
authors.lastname: Segalla
authors.forename: Veronica
authors.initials: V
authors.lastname: De Marco
authors.forename: Giorgio Mario
authors.initials: GM
authors.lastname: Giacometti
authors.forename: Ildikò
authors.initials: I
authors.lastname: Szabò
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018118:Chloride Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D018724:Spinacia oleracea / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D018118:Chloride Channels; D010940:Plant Proteins; D010100:Oxygen