title: The kinase LYK5 is a major chitin receptor in Arabidopsis and forms a chitin-induced complex with related kinase CERK1.
abstract: Chitin is a fungal microbe-associated molecular pattern recognized in Arabidopsis by a lysin motif receptor kinase (LYK), AtCERK1. Previous research suggested that AtCERK1 is the major chitin receptor and mediates chitin-induced signaling through homodimerization and phosphorylation. However, the reported chitin binding affinity of AtCERK1 is quite low, suggesting another receptor with high chitin binding affinity might be present. Here, we propose that AtLYK5 is the primary chitin receptor in Arabidopsis. Mutations in AtLYK5 resulted in a significant reduction in chitin response. However, AtLYK5 shares overlapping function with AtLYK4 and, therefore, Atlyk4/Atlyk5-2 double mutants show a complete loss of chitin response. AtLYK5 interacts with AtCERK1 in a chitin-dependent manner. Chitin binding to AtLYK5 is indispensable for chitin-induced AtCERK1 phosphorylation. AtLYK5 binds chitin at a much higher affinity than AtCERK1. The data suggest that AtLYK5 is the primary receptor for chitin, forming a chitin inducible complex with AtCERK1 to induce plant immunity.
authors.affiliation: Division of Plant Sciences, National Center for Soybean Biotechnology, University of Missouri, Columbia, United States.
authors.forename: Yangrong
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Division of Plant Sciences, National Center for Soybean Biotechnology, University of Missouri, Columbia, United States.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Division of Plant Sciences, National Center for Soybean Biotechnology, University of Missouri, Columbia, United States.
authors.forename: Kiwamu
authors.identifier: http://orcid.org/0000-0001-5045-560X
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Division of Plant Sciences, National Center for Soybean Biotechnology, University of Missouri, Columbia, United States.
authors.forename: Cuong T
authors.initials: CT
authors.lastname: Nguyen
authors.affiliation: Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne, United States.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Jedrzejczak
authors.affiliation: Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne, United States.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Joachimiak
authors.affiliation: Division of Plant Sciences, National Center for Soybean Biotechnology, University of Missouri, Columbia, United States.
authors.forename: Gary
authors.initials: G
authors.lastname: Stacey
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000276:immunology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D010766:Phosphorylation; D057865:Plant Immunity; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D055503:Protein Multimerization; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D011956:Receptors, Cell Surface; D002686:Chitin; D014443:Tyrosine; D012694:Serine; C000599656:LYK5 protein, Arabidopsis; D011494:Protein Kinases; C525882:CERK1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases
keywords: Arabidoposis; CERK1; LYK5; arabidopsis; chitin receptor; plant biology; plant innate immunity