title: The Bacterial Effector AvrB-Induced RIN4 Hyperphosphorylation Is Mediated by a Receptor-Like Cytoplasmic Kinase Complex in Arabidopsis.
abstract: Bacterial pathogen Pseudomonas syringae delivers diverse type III effectors into host cells to interfere with their immune responses. One of the effectors, AvrB, targets a host guardee protein RIN4 and induces RIN4 phosphorylation in Arabidopsis. Phosphorylated RIN4 activates the immune receptor RPM1 to mount defense. AvrB-induced RIN4 phosphorylation depends on RIPK, a receptor-like cytoplasmic kinase (RLCK). In this study, we found several other RLCKs that were also able to phosphorylate RIN4. We demonstrated that these RLCKs formed a complex with RIPK and were functionally redundant to RIPK. We also found that unphosphorylated RIN4 was epistatic to phosphorylated RIN4 in terms of RPM1 activation. AvrB-induced RLCK gene expression and phosphorylated RIN4-triggered RPM1 activation required RAR1, a central regulator in plant innate immunity. Our results unravel a mechanism in which plants employ multiple kinases to hyperphosphorylate the guardee protein RIN4 to ensure immune activation during pathogen invasion.
authors.affiliation: 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.affiliation: 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.|2 College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China; and.
authors.forename: Xuming
authors.initials: X
authors.lastname: Luo
authors.affiliation: 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Li
authors.affiliation: 3 Beijing Key Laboratory of Agricultural Product Detection and Control for Spoilage Organisms and Pesticides, Beijing University of Agriculture, Beijing, 102206, China.
authors.forename: Zongyi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.|2 College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China; and.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D009154:Mutation; D010766:Phosphorylation; D030821:Plants, Genetically Modified; D011485:Protein Binding; D044224:Pseudomonas syringae / Q000235:genetics* / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C100931:AvrB protein, Pseudomonas syringae; D001426:Bacterial Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C453279:RIN4 protein, Arabidopsis; C095014:RPM1 protein, Arabidopsis; D018160:Receptors, Cytoplasmic and Nuclear