| Title |
REVIEW] Recent Findings about the Yersinia enterocolitica Phage Shock Protein Response |
| Author |
Saori Yamaguchi and Andrew J. Darwin* |
| Address |
Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA |
| Bibliography |
Journal of Microbiology, 50(1),1-7, 2012,
|
| DOI |
|
| Key Words |
Yersinia, stress-response, secretin, membrane, virulence |
| Abstract |
The phage shock protein (Psp) system is a conserved extracytoplasmic
stress response in bacteria that is essential
for virulence of the human pathogen Yersinia enterocolitica.
This article summarizes some recent findings about Y. enterocolitica
Psp system function. Increased psp gene expression
requires the transcription factor PspF, but under
non-inducing conditions PspF is inhibited by an interaction
with another protein, PspA, in the cytoplasm. A Psp-inducing
stimulus causes PspA to relocate to the cytoplasmic
membrane, freeing PspF to induce psp gene expression.
This PspA relocation requires the integral cytoplasmic
membrane proteins, PspB and PspC, which might sense an
inducing trigger and sequester PspA by direct interaction.
The subsequent induction of psp gene expression increases
the PspA concentration, which also allows it to contact the
membrane directly, perhaps for its physiological function.
Mutational analysis of the PspB and PspC proteins has revealed
that they both positively and negatively regulate psp
gene expression and has also identified PspC domains associated
with each function. We also compare the contrasting
physiological roles of the Psp system in the virulence of Y.
enterocolitica and Salmonella enterica sv. Typhimurium (S.
Typhimurium). In S. Typhimurium, PspA maintains the
proton motive force, which provides the energy needed to
drive ion importers required for survival within macrophages.
In contrast, in the extracellular pathogen Y. enterocolitica,
PspB and PspC, but not PspA, are the Psp components
needed for virulence. PspBC protect Y. enterocolitica from
damage caused by the secretin component of its type 3 secretion
system, an essential virulence factor. |
