title: A role for N-WASP in invasin-promoted internalisation.
abstract: Phagocytosis of Yersinia pseudotuberculosis occurs through interaction of the bacterial protein invasin with beta1-integrins. Here we report that N-WASP plays a role in internalisation of an invasin-expressing, avirulent strain of Y. pseudotuberculosis. Ectopic expression of N-WASP mutants, which affect recruitment of the Arp2/3 complex to the phagosome, reduces uptake of Yersinia. In addition, expression of the Cdc42/Rac-binding (CRIB) region of N-WASP has an inhibitory effect on uptake. Using GFP-tagged Rho GTPase mutants, we provide evidence that Rac1, but not Cdc42, is important for internalisation. Furthermore, activated Rac1 rescues Toxin B, CRIB and Src family kinase inhibitor PP2-mediated impairment of uptake. Our observations indicate that invasin-mediated phagocytosis occurs via a Src and WASP family-dependent mechanism(s), involving the Arp2/3 complex and Rac, but does not require Cdc42.
authors.affiliation: Department of Microbiology, Umeå University, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: McGee
authors.forename: M
authors.initials: M
authors.lastname: Zettl
authors.forename: M
authors.initials: M
authors.lastname: Way
authors.forename: M
authors.initials: M
authors.lastname: Fällman
mesh_terms: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D010587:Phagocytosis; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D015398:Signal Transduction; D014162:Transfection; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D015011:Yersinia pseudotuberculosis / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; C495771:WASL protein, human; C109903:WIPF1 protein, human; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; C053476:invasin, Yersinia; D049452:Green Fluorescent Proteins; D019061:src-Family Kinases; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins