INVESTIGADORES
CASTELLI maria Eugenia
congresos y reuniones científicas
Título:
“Characterization of regulatory mechanisms of ShlA hemolysin expression in Serratia marcescens”
Autor/es:
STEPANENKO, TATIANA; DI VENANZIO, GISELLA; CASTELLI, MARÍA E.; GARCIA VESCOVI ELEONORA
Lugar:
Potrero de los Funes, San Luis
Reunión:
Congreso; XLVII Reunión anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
The ShlA hemolysin of Serratia marcescens is one of the major virulence factors of this opportunistic pathogen. ShlA together with ShlB, an outer membrane protein, required for secretion and activation of ShlA, form a two-partner system encoded by the shlBA operon. It has been previously reported that ShlA presents cytotoxic activity in several cellular lines, and we have recently demonstrated that it is also responsible for the autophagic phenotype induced by Serratia in epithelial cells. We have also previously determined that the Rcs regulatory system modulates flagellar biogenesis and the expression of the PhlA phospholipase in response to structural alterations in the bacterial envelope. In this work, we analyze the influence of the Rcs phosphorelay system on ShlA synthesis regulation. We found that the rcsB mutant strain presents higher hemolytic activity than the wild type strain, in different growth conditions. This observation is also supported by immunodetection assays, which show higher levels of ShlA in the rcsB mutant. In agreement with this result, we have found a putative RcsB binding site in the promoter region of shlBA operon, suggesting that Rcs system controls shlA expression at the transcriptional level. Together, our results reveal that, in S. marcescens, the Rcs phosphorelay system is key for the regulation of bacterial virulence determinants.