title: Manipulation of host proteasomes as a virulence mechanism of plant pathogens.
abstract: The ubiquitin-26S proteasome degradation system (UPS) in plants is involved in the signal transduction of many cellular processes, including host immune responses triggered by pathogen attack. Attacking pathogens produce effectors that are translocated into host cells, where they interfere with the host's defense signaling in very specific ways. Perhaps not surprising in view of the broad involvement of the host proteasome in plant immunity, certain bacterial effectors exploit or require the host UPS for their action, as currently best studied in Pseudomonas syringae. Intriguingly, some P. syringae strains also secrete the virulence factor syringolin A, which irreversibly inhibits the proteasome by a novel mechanism. Here, the role of the UPS in plant defense and its exploitation by effectors are summarized, and the biology, taxonomic distribution, and emerging implications for virulence strategies of syringolin A and similar compounds are discussed.
authors.affiliation: Institute of Plant Biology, University of Zurich, 8008 Zurich, Switzerland. rdudler@botinst.uzh.ch
authors.forename: Robert
authors.initials: R
authors.lastname: Dudler
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D008961:Models, Structural; D005810:Multigene Family; D010456:Peptides, Cyclic / Q000737:chemistry / Q000378:metabolism*; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D010940:Plant Proteins / Q000378:metabolism; D010944:Plants / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000378:metabolism / Q000472:pathogenicity*; D015398:Signal Transduction; D025801:Ubiquitin / Q000378:metabolism; D014774:Virulence; D037521:Virulence Factors
chemical_list: D001426:Bacterial Proteins; D010456:Peptides, Cyclic; D010940:Plant Proteins; D025801:Ubiquitin; D037521:Virulence Factors; C407267:syringolin A; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease