Bordetella bronchisepticaDermonecrotizing Toxin, Which Activates a Small GTP-Binding Protein Rho, Induces Membrane Organelle Proliferation and Caveolae Formation

Infection of Human Endothelial Cells withBartonella bacilliformisIs Dependent on Rho and Results in Activation of Rho

“…We conclude that the increased internalization seen after 16 h is due to the prior, maximal activation of Rho. Shigella flexneri is another bacteria known to involve Rho in process of internalization in the eukaryotic cells, which can be blocked by C3 exoenzyme treatment (1,35).…”

Bacterial toxins and the Rho GTP-binding protein: what microbes teach us about cell regulation

“…The existence of caveolin in the induction of shc phosphorylation by integrins is explained by recruitment of both shc and a kinase by caveolae at the level of focal adhesion points (Wary et al, 1996). As discussed above, once activated by a CNF1-like toxin, Rho seems to increase the number of caveolae at the level of cell surface (Senda et al, 1997). Is it possible that Rho, by modulating the efficiency of endocytotic pathways together with its ability to cluster integrins, plays a central role in the decision of a cell to proliferate, differentiate or commit suicide?…”

“…CNF1 also induces phosphorylation of p125 FAK kinase and paxillin which are localized in focal adhesion contacts (Lacerda et al, 1997) and provokes the relocalization of myosin type 2 into stress fibers (Fiorentini et al, 1997a). Recently, it has been shown that a toxin which exhibits an enzymatic activity identical to that of CNF1 on Rho stimulates the formation of caveolae (Senda et al, 1997), whereas C3 microinjection into Xenopus ovocytes blocked selectively the non-clathrin dependent endocytic pathway (Schmalzing et al, 1996). Caveolae, whose major protein is caveolin, are small (Rubin et al, 1988) inhibits (Rubin et al, 1988) inhibits (Chardin et al, 1989) activates inhibits (Schmalzing et al, 1996) inhibits (Fujihara et al, 1997) inhibits (Aullo et al, 1993) inhibits (Chong et al, 1994) activates (Henning et al, 1997) Rho (Chardin et al, 1997) NAD (Chardin et al, 1989) asparagine 41 (Sekine et al, 1989) ADP-ribosyltransferase (Rubin et al, 1988) activates (Lacerda et al, 1997) inhibits (Caprioli et al, 1983) activates (Fiorentini et al, 1988) ?…”

“…Caveolae, whose major protein is caveolin, are small (Rubin et al, 1988) inhibits (Rubin et al, 1988) inhibits (Chardin et al, 1989) activates inhibits (Schmalzing et al, 1996) inhibits (Fujihara et al, 1997) inhibits (Aullo et al, 1993) inhibits (Chong et al, 1994) activates (Henning et al, 1997) Rho (Chardin et al, 1997) NAD (Chardin et al, 1989) asparagine 41 (Sekine et al, 1989) ADP-ribosyltransferase (Rubin et al, 1988) activates (Lacerda et al, 1997) inhibits (Caprioli et al, 1983) activates (Fiorentini et al, 1988) ? activates (Senda et al, 1997) activates (Fiorentini et al, 1997a) activates (Fiorentini et al, 1988) activates (Fiorentini et al, 1997a) inhibits (Fiorentini et al, 1998) Rho (Flatau et al, 1997) none (Flatau et al, 1997) glutamine 63 (Flatau et al, 1997) deamidase (Flatau et al, 1997) CNF1 and C3 activities on Rho C Fiorentini et al Figure 4 Possible pivotal role of Rho in cell multiplication, differentiation or apoptosis. Rho-GTP allows cell division by inhibiting receptor-mediated endocytosis and activating pinocytosis.…”

“…This mechanism will ensure the activity for signalling on an extracellular matrix. Concomitantly activated-Rho will increase the traffic and synthesis of caveolae (Senda et al, 1997) bringing shc and tyrosine kinases to the level of integrins (Wary et al, 1996). Moreover, it will inhibit the formation of clathrin coated vesicles forcing receptors implicated in the control of mitogenicity to remain at the cell surface thus increasing their capacity to stimulate cell division (Viera et al, 1996).…”