title: Identification of amino acid residues important for the arsenic resistance function of Arabidopsis ABCC1.
abstract: The Arabidopsis ATP-Binding Cassette (ABC) transporter ABCC1 sequesters arsenic (As)-phytochelatin conjugates into the vacuole, thereby conferring As resistance. Here, we report the results of a screen for phosphorylation-dependent regulation sites of AtABCC1. Variants of AtABCC1 harboring mutations that replaced amino acid residues Tyr682, Tyr709, Tyr822, Ser846, Ser1278, or Thr1408with alanine confer reduced resistance and decrease the intracellular As content relative to wild-type AtABCC1 when heterologously expressed in the SM7 yeast strain. This suggests that these mutations compromise the vacuolar sequestration of As by AtABCC1. Furthermore, through a phosphomimic mutant study, we found that phosphorylation of Ser846is required for the As resistance function of AtABCC1. Our analysis provides a first clue as to the phosphorylation-mediated regulation of AtABCC1 activity.
authors.affiliation: Department of Life Science, Pohang University of Science and Technology, Korea.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Life Science, Pohang University of Science and Technology, Korea.
authors.forename: Jae-Ung
authors.initials: JU
authors.lastname: Hwang
authors.affiliation: Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Korea.
authors.forename: Won-Yong
authors.initials: WY
authors.lastname: Song
authors.affiliation: Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Korea.|Institut für Pflanzenbiologie, Universität Zürich, Switzerland.
authors.forename: Enrico
authors.initials: E
authors.lastname: Martinoia
authors.affiliation: Department of Life Science, Pohang University of Science and Technology, Korea.|Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Korea.
authors.forename: Youngsook
authors.initials: Y
authors.lastname: Lee
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001151:Arsenic / Q000633:toxicity*; D015153:Blotting, Western; D004351:Drug Resistance / Q000235:genetics*; D020125:Mutation, Missense; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000235:genetics / Q000378:metabolism
chemical_list: C000589124:ABCC1 protein, Arabidopsis; D018528:ATP-Binding Cassette Transporters; D000596:Amino Acids; D029681:Arabidopsis Proteins; D012694:Serine; D001151:Arsenic
keywords: ABC transporter; arsenic; linker phosphorylation