[ODP-069] The role of intrabacterial nanotransportation system for cholera toxin in Vibrio cholerae
The intrabacterial nanotransportation system (ibNoTS) is a biological apparatus that relocates molecules within the cytoplasm in accordance with changes in the extrabacterial environment. The system was first discovered in Helicobacter pylori, and then was also found in V. cholerae. The route of ibNoTS for H. pylori CagA is reported to be associated with the MreB filament, and the route of ibNoTS for urease is shown to be associated with the FtsZ filament. The V. cholerae possesses the ibNoTS for transporting cholera toxin (CT) from the inner portion toward the peripheral portion of the cytoplasm by extrabacterial alkaline environment, and ATP closely associates with V. cholerae ibNoTS for transporting CT. However, the transportation routes of the ibNoTS for CT has not yet been examined in detail. In this study, we demonstrated by immunoelectron microscopy that CT along the route of ibNoTS localizes closely with the MreB filament in the bacterium, and MreB polymerization inhibitor A22 obstructs ibNoTS for CT. Supporting this, we found by enzyme immunoassay that the A22 were associated with decease of CT secretion by ibNoTS followed, and found that CT interacted with MreB. These findings indicate that CT along the route of ibNoTS is closely associated with the MreB filament. We propose that the route of ibNoTS for CT is associated with the MreB filament in V. cholerae.