title: Microtubule-dependent regulation of Rho GTPases during internalisation of Yersinia pseudotuberculosis.
abstract: Internalisation of the human pathogen Yersinia pseudotuberculosis via interaction of bacterial invasin with host beta1 integrins depends on the actin cytoskeleton and involves Src family kinases, focal adhesion kinase, p130Crk-associated substrate, proline-rich tyrosine kinase 2, Rac, Arp 2/3 complex and WASP family members. We show here that Rho GTPases are regulated by the microtubule system during bacterial uptake. Interfering with microtubule organisation using nocodazole or paclitaxel suppressed uptake by HeLa cells. The nocodazole effect on microtubule depolymerisation was partially inhibited through overexpression of Rac, Cdc42, RhoG or RhoA and completely prevented by expression of Vav2. This suggests that microtubules influence Rho GTPases during invasin-mediated phagocytosis and in the absence of functional microtubules Vav2 can mimic their effect on one, or more, of the Rho family GTPases. Lastly, overexpression of p50 dynamitin partially inhibited bacterial uptake and this effect was also blocked by co-expression of Vav2, thus further implicating this guanine nucleotide exchange factor in activating Rho GTPases for internalisation during loss of microtubule function.
authors.affiliation: Department of Molecular Biology, Umeå University, 901 87, Umeå, Sweden.
authors.forename: Karen
authors.initials: K
authors.lastname: McGee
authors.forename: Per
authors.initials: P
authors.lastname: Holmfeldt
authors.forename: Maria
authors.initials: M
authors.lastname: Fällman
mesh_terms: D001693:Biological Transport, Active / Q000187:drug effects; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D015739:Nocodazole / Q000494:pharmacology; D015513:Oncogene Proteins / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology; D051567:Proto-Oncogene Proteins c-vav; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015011:Yersinia pseudotuberculosis / Q000472:pathogenicity*; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: C000606361:DCTN2 protein, human; D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D015513:Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; D011993:Recombinant Fusion Proteins; C093651:VAV2 protein, human; C075397:RHOG protein, human; D020558:GTP Phosphohydrolases; D004398:Dyneins; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins; D017239:Paclitaxel; D015739:Nocodazole