title: A Pseudomonas syringae ADP-ribosyltransferase inhibits Arabidopsis mitogen-activated protein kinase kinases.
abstract: The successful recognition of pathogen-associated molecular patterns (PAMPs) as a danger signal is crucial for plants to fend off numerous potential pathogenic microbes. The signal is relayed through mitogen-activated protein kinase (MPK) cascades to activate defenses. Here, we show that the Pseudomonas syringae type III effector HopF2 can interact with Arabidopsis thaliana MAP KINASE KINASE5 (MKK5) and likely other MKKs to inhibit MPKs and PAMP-triggered immunity. Inhibition of PAMP-induced MPK phosphorylation was observed when HopF2 was delivered naturally by the bacterial type III secretion system. In addition, HopF2 Arg-71 and Asp-175 residues that are required for the interaction with MKK5 are also necessary for blocking MAP kinase activation, PAMP-triggered defenses, and virulence function in plants. HopF2 can inactivate MKK5 and ADP-ribosylate the C terminus of MKK5 in vitro. Arg-313 of MKK5 is required for ADP-ribosylation by HopF2 and MKK5 function in the plant cell. Together, these results indicate that MKKs are important targets of HopF2.
authors.affiliation: College of Life Sciences, Beijing Normal University, Beijing 100875, China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Wang
authors.forename: Jifeng
authors.initials: J
authors.lastname: Li
authors.forename: Shuguo
authors.initials: S
authors.lastname: Hou
authors.forename: Xingwei
authors.initials: X
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.forename: Dongtao
authors.initials: D
authors.lastname: Ren
authors.forename: She
authors.initials: S
authors.lastname: Chen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Tang
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Zhou
mesh_terms: D036002:ADP Ribose Transferases / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors*; D001426:Bacterial Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000276:immunology / Q000382:microbiology; D044224:Pseudomonas syringae / Q000201:enzymology* / Q000472:pathogenicity; D014774:Virulence
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D036002:ADP Ribose Transferases; C519872:MKK5 protein, Arabidopsis; D020929:Mitogen-Activated Protein Kinase Kinases