title: Bacterial effector activates jasmonate signaling by directly targeting JAZ transcriptional repressors.
abstract: Gram-negative bacterial pathogens deliver a variety of virulence proteins through the type III secretion system (T3SS) directly into the host cytoplasm. These type III secreted effectors (T3SEs) play an essential role in bacterial infection, mainly by targeting host immunity. However, the molecular basis of their functionalities remains largely enigmatic. Here, we show that the Pseudomonas syringae T3SE HopZ1a, a member of the widely distributed YopJ effector family, directly interacts with jasmonate ZIM-domain (JAZ) proteins through the conserved Jas domain in plant hosts. JAZs are transcription repressors of jasmonate (JA)-responsive genes and major components of the jasmonate receptor complex. Upon interaction, JAZs can be acetylated by HopZ1a through a putative acetyltransferase activity. Importantly, P. syringae producing the wild-type, but not a catalytic mutant of HopZ1a, promotes the degradation of HopZ1-interacting JAZs and activates JA signaling during bacterial infection. Furthermore, HopZ1a could partially rescue the virulence defect of a P. syringae mutant that lacks the production of coronatine, a JA-mimicking phytotoxin produced by a few P. syringae strains. These results highlight a novel example by which a bacterial effector directly manipulates the core regulators of phytohormone signaling to facilitate infection. The targeting of JAZ repressors by both coronatine toxin and HopZ1 effector suggests that the JA receptor complex is potentially a major hub of host targets for bacterial pathogens.
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside, California, United States of America ; Center for Plant Cell Biology, University of California, Riverside, California, United States of America.
authors.forename: Shushu
authors.initials: S
authors.lastname: Jiang
authors.forename: Jian
authors.initials: J
authors.lastname: Yao
authors.forename: Ka-Wai
authors.initials: KW
authors.lastname: Ma
authors.forename: Huanbin
authors.initials: H
authors.lastname: Zhou
authors.forename: Jikui
authors.initials: J
authors.lastname: Song
authors.forename: Sheng Yang
authors.initials: SY
authors.lastname: He
authors.forename: Wenbo
authors.initials: W
authors.lastname: Ma
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism; D000596:Amino Acids / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007192:Indenes / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000502:physiology*; D044224:Pseudomonas syringae / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D003517:Cyclopentanes; D007192:Indenes; D054883:Oxylipins; D012097:Repressor Proteins; C058487:coronatine; C011006:jasmonic acid