title: A Pseudomonas aeruginosa-secreted protease modulates host intrinsic immune responses, but how?
abstract: Recently, we found that the Pseudomonas aeruginosa type II secreted protease IV functions as a unique Arabidopsis innate immunity elicitor. The protease IV-activated pathway involves G protein signaling and raises the question of how protease elicitation leads to the activation of G protein-mediated signaling, because plants do not appear to have metazoan-like G protein-coupled receptors. Importantly, our data suggest that Arabidopsis has evolved a mechanism to detect the proteolytic activity of a pathogen-encoded protease, supporting the host-pathogen arms race model. In the case of opportunistic multi-host pathogens like P. aeruginosa, however, it is not plausible that P. aeruginosa is simultaneously co-evolving in a gene-for-gene manner with all of its potential hosts, which include plants, nematodes, insects, and mammals. This prompts us to ask what is the driving force for co-evolution of defense response in Arabidopsis and pathogenesis of P. aeruginosa, which might not have been subject to iterative cycles of evolutionary selections.
authors.affiliation: Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada. zhenyu.cheng@dal.ca.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Cheng
mesh_terms: D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology*; D007113:Immunity, Innate; D010935:Plant Diseases; D011552:Pseudomonas Infections / Q000378:metabolism* / Q000503:physiopathology; D012697:Serine Endopeptidases; D015398:Signal Transduction
chemical_list: C038495:Pseudomonas serine proteinase; D012697:Serine Endopeptidases
keywords: immunity; pathogen; protease; signaling