congresos y reuniones científicas
ENTEROBACTIN PROTECTS Escherichia coli FROM THE ROS-MEDIATED TOXIC EFFECTS OF COPPER
PERALTA, DAIANA; ADLER, CONRADO; CORBALAN, NATALIA; PAZ GARCÍA, ENRIQUE CARLOS; VINCENT, PAULA; POMARES, FERNANDA
Congreso; SAIB; 2015
Siderophores are metal-chelating agents produced by bacteria under Fe-limiting conditions. Its primary function is to chelate the ferric iron and therefore make it available. Recent reports indicate that siderophores have wider and more complex functions than those known. We previously reported the requirement of enterobactin, a catechol siderophore produced by E. coli, for colony development in minimal media (M9) and proposed a new function as an intracellular oxidative stress protector. Now, we analyzed the role of enterobactin in copper toxicity. We showed that the lack of enterobactin increased copper cell sensitivity. Addition of enterobactin to the media protected cells; on the other hand, supplementation with iron didn?t impact on the sensitivity to copper. Besides, we observed that enterobactin must to be internalized and hydrolyzed to confer a full protection against copper damage. Also, entE expression increased in cells growing in M9 and LB supplemented with copper. Finally, we found that the addition of copper to entE mutant increased levels of reactive oxygen species, which were lowered in the presence of exogenous enterobactin. Results suggest that the copper toxicity in enterobactin deficient mutants could be due to the oxidative stress generated by this metal and support our hypothesis implying cathecols siderophores in an oxidative stress protection function.