RpoS integrates CRP, Fis, and PhoP signaling pathways to control Salmonella Typhi hlyE expression
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Fecha
2014-05
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
BioMed Central Ltd.
Nombre de Curso
Licencia CC
Atribution 4.0 International (CC BY 4.0
Licencia CC
https://creativecommons.org/licenses/by/4.0/deed.es
Resumen
Abstract
Background: SPI-18 is a pathogenicity island found in some Salmonella enterica serovars, including S. Typhi. SPI-18
harbors two ORFs organized into an operon, hlyE and taiA genes, both implicated in virulence. Regarding the hlyE
regulation in S. Typhi, it has been reported that RpoS participates as transcriptional up-regulator under low pH and
high osmolarity. In addition, CRP down-regulates hlyE expression during exponential growth. Previously, it has
been suggested that there is another factor related to catabolite repression, different from CRP, involved in the
down-regulation of hlyE. Moreover, PhoP-dependent hlyE up-regulation has been reported in bacteria cultured
simultaneously under low pH and low concentration of Mg2+. Nevertheless, the relative contribution of each
environmental signal is not completely clear. In this work we aimed to better understand the regulation of hlyE in
S. Typhi and the integration of different environmental signals through global regulators.
Results: We found that Fis participates as a CRP-independent glucose-dependent down-regulator of hlyE. Also, Fis
and CRP seem to exert the repression over hlyE through down-regulating rpoS. Moreover, PhoP up-regulates hlyE
expression via rpoS under low pH and low Mg2+ conditions.
Conclusions: All these results together show that, at least under the tested conditions, RpoS is the central regulator
in the hlyE regulatory network, integrating multiple environmental signals and global regulators.
Notas
Indexación: Scopus.
Palabras clave
HlyE, RpoS, PhoP, CAMP-Receptor Protein, Fis Protein, Catabolite Repression
Citación
BMC Microbiology. Volume 14, Issue 13. 1 May 2014 Article number 139
DOI
DOI: 10.1186/1471-2180-14-139