Copper homeostasis in Salmonella enterica. Understanding the Role of Metal Ions in Biological Systems-Gordon Research Conference.

ZHAO Z; CHECA SK; SONCINI FC; ARGÜELLO JM

West Dover

Congreso; Understanding the Role of Metal Ions in Biological Systems; 2023

Gordon Research Conference

Salmonella enterica is a human pathogen that causes gastroenteritis and systemic diseases. Copper, as an abundant trace metal, plays a critical role in the physiology of organisms and serves as a key factor in the virulence of pathogenic bacteria as well as host innate immune system. Others and our laboratories have studied Cu homeostasis of model organisms as E. Coli, Pseudomonas and Salmonella. Aiming to elucidate the molecular network that manages and distributes Cu in Salmonella, we have used mutant strains of the membrane efflux/influx transporters, chaperones, redox response systems. We have analyzed their Cu2+ sensitivity and the total steady state Cu levels of the various stains in the absence and presence of external added Cu2+.Stains carrying deletion of cueO, scsABCD, tolC, CopA, cpxRA, and cueR genes display heightened sensitivity to Cu2+. Using a filter-based method, we observe higher Cu levels even in the absence of external Cu in strains carrying deletion in cuproprotein CueO and efflux transporters TolC, CopA, and GolT. Interestingly, mutation of the putative efflux transporter CuiT and the regulators CpxRA lead to reduced Cu levels the presence and absence of added external Cu. Deletion of the scsABCD system or the gene coding for the periplasmic CueP had little or no effect on Cu levels. These results suggest that these components collectively play a role in Cu distribution.