[ODP-136] Analysis of the functional domain of BopN, a type III effector produced by Bordetella
BopN promotes the translocation of the cytotoxicity-inducing factor BteA into the host cell, however, it is unclear which region within BopN is responsible for this function. To investigate the functional region of BopN, we constructed plasmids encoding a truncated BopN and the N-terminal 448 aa BteA fused to CyaA. Those plasmids were introduced into B. bronchiseptica BopN-deficient strains (ΔBopN). We infected L2 cells with B. bronchiseptica harboring the plasmid and measured the intracellular cAMP levels. The results showed that infection with the strain producing 41-50tt aa- or 226-300th aa-deleted BopN resulted in no increase in cAMP concentration. In contrast, the concentration of cAMP was increased in the case of the strain producing the 11-40th aa- or 201-225th aa-deleted BopN. Next, we infected L2 cells with ΔBopN harboring a plasmid encoding the truncated BopN and measured LDH in the culture supernatant. The results showed that the release of LDH was reduced when ΔBopN producing the 11-50th aa- or 201-300th aa-deleted BopN was infected when compared to that of the wild-type strain. These results suggest that 41-50th and 226-300th aa regions of BopN were involved in the translocation of BteA. On the other hand, the 11-50th aa and 201-300th aa of BopN were seemed to be involved in promoting the cytotoxicity of BteA after translocation into host cells.