INVESTIGADORES
CHECA Susana Karina
congresos y reuniones científicas
Título:
A CONSORTIUM OF REGULATORY SYSTEMS CONTROLS THE EXPRESSION OF A SALMONELLA-SPECIFIC EFFLUX COMPLEX
Autor/es:
CERMINATI, S.; CHECA, S. K.; SONCINI, F. C.
Lugar:
Mendoza
Reunión:
Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2012
Institución organizadora:
Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular
Resumen:
CBA efflux systems are tripartite protein complexes that direct export of metal ions, xenobiotics or drugs either from the cytoplasm, the inner membrane or the periplasm into the extracellular space. GesABC is one of the five Salmonella CBA efflux pumps whose transcription is controlled by the Au-sensor GolS. Among the three transcriptional units controlled by GolS, gesABC has the most divergent GolS-dependent operator, resulting in its delayed expression in the presence of Au ions. Besides its essential role in Au-resistance, the GesABC system can also mediate the transport of different drugs in a strain deleted in the main drug transporter AcrAB, suggesting additional roles for cell detoxification. Using  bioinformatics we identified putative cis-acting regulatory sequences recognized by global as well as stress-induced transcriptional regulatory systems that would control the expression of the efflux pump under different conditions. Their effective control of gesABC expression was verified by reporter expression on strains deleted in different regulatory systems. Specific recognition by these systems was confirmed by in vitro assays. Our results indicate that a regulatory system consortium controls the expression of gesABC, providing the proper supply of the efflux complex according to the quality and severity of different stress conditions  that the pathogen encounters.