title: RETRACTED: A type I-secreted, sulfated peptide triggers XA21-mediated innate immunity.
abstract: The rice Xa21 gene confers immunity to most strains of the bacterium Xanthomonas oryzae pv. oryzae (Xoo). Liquid chromatography-tandem mass spectrometry analysis of biologically active fractions from Xoo supernatants led to the identification of a 194-amino acid protein designated Ax21 (activator of XA21-mediated immunity). A sulfated, 17-amino acid synthetic peptide (axY(S)22) derived from the N-terminal region of Ax21 is sufficient for activity, whereas peptides lacking tyrosine sulfation are biologically inactive. Using coimmunoprecipitation, we found that XA21 is required for axY(S)22 binding and recognition. axY(S)22 is 100% conserved in all analyzed Xanthomonas species, confirming that Ax21 is a pathogen-associated molecular pattern and that XA21 is a pattern recognition receptor.
authors.affiliation: Department of Plant Pathology, University of California, Davis, CA 95616, USA.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Han
authors.forename: Malinee
authors.initials: M
authors.lastname: Sririyanum
authors.forename: Chang-Jin
authors.initials: CJ
authors.lastname: Park
authors.forename: Young-Su
authors.initials: YS
authors.lastname: Seo
authors.forename: Pamela C
authors.initials: PC
authors.lastname: Ronald
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017124:Conserved Sequence; D005798:Genes, Bacterial; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D047468:Immunoprecipitation; D008969:Molecular Sequence Data; D012275:Oryza / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051192:Receptors, Pattern Recognition / Q000235:genetics / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism; D014974:Xanthomonas / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D010446:Peptide Fragments; D010940:Plant Proteins; D051192:Receptors, Pattern Recognition; D013431:Sulfates; C097148:Xa21 protein, Oryza sativa; D014443:Tyrosine; D017346:Protein Serine-Threonine Kinases