title: Cell vacuolization induced by Helicobacter pylori VacA cytotoxin does not depend on late endosomal SNAREs.
abstract: Cellular vacuoles induced by the Helicobacter pylori vacuolating cytotoxin VacA originate from late endosomal compartments. Their biogenesis requires the activity of both rab7 GTPase and the ATPase proton pump. The toxin has been suggested to cause an increased luminal osmotic pressure via its anion-specific channel activity localized on late endosomal compartments after endocytosis. Here, we show that the extensive membrane fusion that takes place in the transition from the small late endosomal compartments to the large vacuoles does not depend on soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor (SNARE) proteins. The process of vacuolization leads to disappearance of the large array of internal membranes of late endosomes. We suggest that most of the vacuole-limiting membrane derives from internal membranes.
authors.affiliation: Centro CNR Biomembrane and Dipartimento di Scienze Biomediche Sperimentali, Università di Padova, Via G. Colombo 3, 35121, Padova, Italy. marina@civ.bio.unipd.it
authors.forename: M
authors.initials: M
authors.lastname: de Bernard
authors.forename: M
authors.initials: M
authors.lastname: Moschioni
authors.forename: A
authors.initials: A
authors.lastname: Habermann
authors.forename: G
authors.initials: G
authors.lastname: Griffiths
authors.forename: C
authors.initials: C
authors.lastname: Montecucco
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001427:Bacterial Toxins / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003603:Cytotoxins / Q000378:metabolism; D011992:Endosomes / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D006367:HeLa Cells; D016480:Helicobacter pylori / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D008561:Membrane Fusion / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008845:Microinjections; D050765:Qa-SNARE Proteins; D050600:SNARE Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D014162:Transfection; D014617:Vacuoles / Q000378:metabolism* / Q000648:ultrastructure; D033921:Vesicular Transport Proteins
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D002352:Carrier Proteins; D003603:Cytotoxins; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; D050600:SNARE Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; C074689:VacA protein, Helicobacter pylori; D033921:Vesicular Transport Proteins