title: Peroxidase activity of annexin 1 from Arabidopsis thaliana.
abstract: On the basis of earlier reports suggesting that annexin A1 from Arabidopsis thaliana (AnnAt1) participates in limiting the excessive levels of reactive oxygen species during oxidative burst in plants, we examined the sensitivity of recombinant AnnAt1 to hydrogen peroxide and its peroxidase activity. Purified recombinant protein remains mostly alpha-helical and binds to lipids in a calcium-dependent manner. Upon oxidation recombinant AnnAt1 exhibits a tendency to form dimers in vitro. AnnAt1 is also sensitive to the presence of reducing agents, suggesting that AnnAt1 is a redox sensor in plant cells. Moreover, using two independent methods we found that AnnAt1 displayed peroxidase activity which is probably related to the presence of a heme-binding domain within AnnAt1, as present in other peroxidases. Indeed, site-directed mutagenesis within this domain resulted in a complete abrogation of the activity of AnnAt1. Furthermore, this activity was found to be sensitive to the phosphorylation state of the protein.
authors.affiliation: Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
authors.forename: Karolina M
authors.initials: KM
authors.lastname: Gorecka
authors.forename: Dorota
authors.initials: D
authors.lastname: Konopka-Postupolska
authors.forename: Jacek
authors.initials: J
authors.lastname: Hennig
authors.forename: Rene
authors.initials: R
authors.lastname: Buchet
authors.forename: Slawomir
authors.initials: S
authors.lastname: Pikula
mesh_terms: D000595:Amino Acid Sequence; D017305:Annexin A1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017302:Annexins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D009195:Peroxidase / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D019163:Reducing Agents / Q000494:pharmacology; D016415:Sequence Alignment
chemical_list: D017305:Annexin A1; D017302:Annexins; D029681:Arabidopsis Proteins; D011994:Recombinant Proteins; D019163:Reducing Agents; D006861:Hydrogen Peroxide; C504971:annexin 1, Arabidopsis; D009195:Peroxidase