title: Characterization of Alternaria infectoria extracellular vesicles.
abstract: Many fungi use membrane vesicles to transport complex molecules across their cell walls. Like mammalian exosomes, fungal vesicles contain lipids, proteins, and polysaccharides, many of which are associated with virulence. Here we identify and characterize extracellular vesicles (EVs) in Alternaria infectoria, a ubiquitous, environmental filamentous fungus that is also an opportunistic human pathogen. Examination of the A. infectoria EVs revealed a morphology similar to that of vesicles described in other fungal species. Of note, proteomic analysis detected a reduced number of vesicle-associated proteins. There were two prevalent categories among the 20 identified proteins, including the polysaccharide metabolism group, probably related to plant host invasion or biosynthesis/degradation of cell wall components, and the nuclear proteins, especially DNA repair enzymes. We also found enzymes related to pigment synthesis, adhesion to the host cell, and trafficking of vesicles/organelles/molecules. This is the first time EV secretions have been identified in a filamentous fungus. We believe that these vesicles might have a role in virulence.
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Portugal.
authors.forename: Branca M A
authors.initials: BM
authors.lastname: Silva
authors.forename: Rafael
authors.initials: R
authors.lastname: Prados-Rosales
authors.forename: Javier
authors.initials: J
authors.lastname: Espadas-Moreno
authors.forename: Julie M
authors.initials: JM
authors.lastname: Wolf
authors.forename: Jose L
authors.initials: JL
authors.lastname: Luque-Garcia
authors.forename: Teresa
authors.initials: T
authors.lastname: Gonçalves
authors.forename: Arturo
authors.initials: A
authors.lastname: Casadevall
mesh_terms: D000528:Alternaria / Q000378:metabolism* / Q000648:ultrastructure; D055354:Exosomes / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D005656:Fungal Proteins / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D020543:Proteome / Q000032:analysis; D037521:Virulence Factors / Q000032:analysis
chemical_list: D005656:Fungal Proteins; D020543:Proteome; D037521:Virulence Factors
keywords: Alternaria infectoria; extracellular vesicles; secreted proteins