To determine the molecular mechanisms of aggressive prostate cancer behavior, we studied RhoGTPases in high and low invasive variants of PC-3 prostate cancer cells. Prior studies with these cells revealed that elevated nuclear factor B (NFB) expression and activity were necessary for the highly invasive phenotype. In the current study, increased RhoA expression was found in the PC-3 highly inva...

The oral fungal microbiota of 30 children with AIDS, of both genders, aged from two to six years, receiving outpatient treatment, was evaluated and compared with that of a control group composed of 30 healthy subjects with matching ages and genders. Virulence factors, such as exoenzyme production, and susceptibility to five antifungal agents using an E-Test kit were evaluated. C. albicans predo...

Rho family GTPases have been assigned important roles in the formation of actin-based morphologies in nonneuronal cells. Here we show that microinjection of Cdc42Hs and Rac1 promoted formation of filopodia and lamellipodia in N1E-115 neuroblastoma growth cones and along neurites. These actin-containing structures were also induced by injection of Clostridium botulinum C3 exoenzyme, which abolis...

Neutrophil motility is crucial to effective host defenses against microorganisms. While uropod retraction is a critical step in the migration of neutrophils, the underlying molecular mechanism is not well understood. Here, we show that inhibition of the Rho small GTPase with C3 exoenzyme prevented the retraction of trailing uropods, indicating that the process of rear release is mediated by a R...

Treatment of human myeloid leukaemic (HL60) cells with Clostridium limosum exoenzyme, which inactivates the small GTP-binding protein Rho by ADP-ribosylation, decreased the basal F-actin content. Inhibition of F-actin occurred after long-term treatment (24 h) of intact HL60 cells or after introduction of the toxin by electropermeabilization in a toxin-concentration-dependent manner. Concomitant...

The intestinal epithelial barrier, which is regulated by the actin cytoskeleton, exhibits permeability changes during inflammation. Here we show that activation of the CysLT(1) receptor by the inflammatory mediator leukotriene D(4) (LTD(4)) causes a rapid increase in stress-fibre formation in intestinal epithelial cells. This effect was mimicked by cytotoxic necrotising factor-1 (CNF-1)-induced...

C3 exoenzyme is a mono-ADPribosyltransferase (ART) that catalyzes transfer of an ADP-ribose moiety from NAD to Rho GTPases. C3 has long been used to study the diverse regulatory functions of Rho GTPases. How C3 recognizes its substrate and ADP-ribosylation proceeds are still poorly understood. Crystal structures of C3-RhoA complex reveal that C3 recognizes RhoA via switch I, switch II and inter...