title: Transcytosis shuts the door for an unwanted guest.
abstract: Penetration resistance is a well-described plant defense process, in which SOLUBLE N-ETHYLMALEIMIDE-SENSITIVE-FACTOR ATTACHMENT RECEPTOR (SNARE) proteins have essential roles in membrane fusion processes. Strong focal accumulation of these proteins at the site of attack by powdery mildew fungi has been considered important for their function. However, recent insight indicates that transcytosis, leading to the formation of exosomes, has an important role in this defense and, furthermore, that strong accumulation of these SNARE proteins with the exosomes is biologically irrelevant. These findings alter the established function of SNAREs in penetration resistance; therefore, in this opinion, we propose that PEN1 and its SNARE partners function on an endosome in their control of penetration resistance.
authors.affiliation: Developmental Genetics, Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 3, D-72076 Tübingen, Germany. Electronic address: mads-eggert.nielsen@zmbp.uni-tuebingen.de.
authors.forename: Mads Eggert
authors.initials: ME
authors.lastname: Nielsen
authors.forename: Hans
authors.initials: H
authors.lastname: Thordal-Christensen
mesh_terms: D017360:Arabidopsis / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001692:Biological Transport; D055354:Exosomes; D008561:Membrane Fusion; D057146:Multivesicular Bodies; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D050765:Qa-SNARE Proteins / Q000378:metabolism*; D050600:SNARE Proteins / Q000378:metabolism*; D057900:Transcytosis / Q000276:immunology*
chemical_list: D029681:Arabidopsis Proteins; C479425:PEN1 protein, Arabidopsis; D050765:Qa-SNARE Proteins; D050600:SNARE Proteins
keywords: ARF-GEF; GNOM; PEN1; ROR2; SNARE; syntaxin