IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
artículos
Título:
CpxR/CpxA-controls scsABCD transcription to counteract copper and oxidative stress in Salmonella Typhimurium
Autor/es:
CHECA, SUSANA K.; CHECA, SUSANA K.; SONCINI, FERNANDO C.; LÓPEZ, CAROLINA; SONCINI, FERNANDO C.; LÓPEZ, CAROLINA
Revista:
JOURNAL OF BACTERIOLOGY
Editorial:
AMER SOC MICROBIOLOGY
Referencias:
Lugar: Washington, D.C.; Año: 2018 vol. 200
ISSN:
0021-9193
Resumen:
Periplasmic thiol/disulfide oxidoreductases participate in the formation and isomerization of disulphide bonds and contribute to the virulence of pathogenic microorganisms. Among the systems encoded in the Salmonella genome, the scsABCD locus was shown to be required to cope with Cu and H2O2 stress. Here we report that this locus forms an operon whose transcription is driven by a promoter upstream of scsA and depends on CpxR/CpxA and on Cu. Furthermore, genes homologues to scsB, scsC and scsD are always detected immediately downstream scsA and in the same genetic arrangement in all scsA-harboring enterobacterial species. Also, a CpxR-binding site is detected upstream scsA in most of these species, providing evidences of an evolutionary conserved function and regulation. Each individual scs gene shows a different role in copper and/or H2O2 resistance, evidencing a hierarchical contribution of these factors in the defense against these intoxicants. A protective effect of Cu-preincubation against H2O2 toxicity and the increased Cu-mediated activation of cpxP in the ΔscsABCD mutant suggest that the CpxR/CpxA-controlled transcription of the ScsABCD system contribute to prevent Cu-toxicity and to restore redox balance at the Salmonella envelope.