title: Direct ubiquitination of pattern recognition receptor FLS2 attenuates plant innate immunity.
abstract: Innate immune responses are triggered by the activation of pattern-recognition receptors (PRRs). The Arabidopsis PRR FLAGELLIN-SENSING 2 (FLS2) senses bacterial flagellin and initiates immune signaling through association with BAK1. The molecular mechanisms underlying the attenuation of FLS2 activation are largely unknown. We report that flagellin induces recruitment of two closely related U-box E3 ubiquitin ligases, PUB12 and PUB13, to FLS2 receptor complex in Arabidopsis. BAK1 phosphorylates PUB12 and PUB13 and is required for FLS2-PUB12/13 association. PUB12 and PUB13 polyubiquitinate FLS2 and promote flagellin-induced FLS2 degradation, and the pub12 and pub13 mutants displayed elevated immune responses to flagellin treatment. Our study has revealed a unique regulatory circuit of direct ubiquitination and turnover of FLS2 by BAK1-mediated phosphorylation and recruitment of specific E3 ligases for attenuation of immune signaling.
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Dongping
authors.initials: D
authors.lastname: Lu
authors.forename: Wenwei
authors.initials: W
authors.lastname: Lin
authors.forename: Xiquan
authors.initials: X
authors.lastname: Gao
authors.forename: Shujing
authors.initials: S
authors.lastname: Wu
authors.forename: Cheng
authors.initials: C
authors.lastname: Cheng
authors.forename: Julian
authors.initials: J
authors.lastname: Avila
authors.forename: Antje
authors.initials: A
authors.lastname: Heese
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Devarenne
authors.forename: Ping
authors.initials: P
authors.lastname: He
authors.forename: Libo
authors.initials: L
authors.lastname: Shan
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005408:Flagellin / Q000276:immunology*; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000276:immunology; D010766:Phosphorylation; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D054730:Protein Interaction Domains and Motifs; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000254:growth & development / Q000276:immunology; D051192:Receptors, Pattern Recognition / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D057149:Ubiquitinated Proteins / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D029681:Arabidopsis Proteins; D050505:Mutant Proteins; D010446:Peptide Fragments; D051192:Receptors, Pattern Recognition; D011993:Recombinant Fusion Proteins; D057149:Ubiquitinated Proteins; D005408:Flagellin; C558941:PUB12 protein, Arabidopsis; C558942:PUB13 protein, Arabidopsis; D044767:Ubiquitin-Protein Ligases; D011494:Protein Kinases; C463660:BAK1 protein, Arabidopsis; C411853:FLS2 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases