Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 8 December 2006:
Vol. 314. no. 5805, pp. 1607 - 1609
DOI: 10.1126/science.1134930
Prev | Table of Contents | Next

Reports

A Positive Feedback Loop Promotes Transcription Surge That Jump-Starts Salmonella Virulence Circuit

Dongwoo Shin,* Eun-Jin Lee, Henry Huang, Eduardo A. Groisman{dagger}

The PhoP/PhoQ two-component system is a master regulator of Salmonella pathogenicity. Here we report that induction of the PhoP/PhoQ system results in an initial surge of PhoP phosphorylation; the occupancy of target promoters by the PhoP protein; and the transcription of PhoP-activated genes, which then subsides to reach new steady-state levels. This surge in PhoP activity is due to PhoP positively activating its own transcription, because a strain constitutively expressing the PhoP protein attained steady-state levels of activation asymptotically, without the surge. The strain constitutively expressing the PhoP protein was attenuated for virulence in mice, demonstrating that the surge conferred by PhoP's positive feedback loop is necessary to jump-start Salmonella's virulence program.

Department of Molecular Microbiology, Howard Hughes Medical Institute, Washington University School of Medicine, Campus Box 8230, 660 South Euclid Avenue, St. Louis, MO 63110, USA.

* Present address: Center for Agricultural Biomaterials, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Korea.

{dagger} To whom correspondence should be addresssed. E-mail: groisman{at}borcim.wustl.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
A two-component system is required for colonization of host cells by meningococcus.
A. Jamet, C. Rousseau, J.-B. Monfort, E. Frapy, X. Nassif, and P. Martin (2009)
Microbiology 155, 2288-2295
   Abstract »    Full Text »    PDF »
Chloroplast two-component systems: evolution of the link between photosynthesis and gene expression.
S. Puthiyaveetil and J. F. Allen (2009)
Proc R Soc B 276, 2133-2145
   Abstract »    Full Text »    PDF »
The sensor kinase PhoQ mediates virulence in Pseudomonas aeruginosa.
W. J. Gooderham, S. L. Gellatly, F. Sanschagrin, J. B. McPhee, M. Bains, C. Cosseau, R. C. Levesque, and R. E. W. Hancock (2009)
Microbiology 155, 699-711
   Abstract »    Full Text »    PDF »
RstA-Promoted Expression of the Ferrous Iron Transporter FeoB under Iron-Replete Conditions Enhances Fur Activity in Salmonella enterica.
J. Jeon, H. Kim, J. Yun, S. Ryu, E. A. Groisman, and D. Shin (2008)
J. Bacteriol. 190, 7326-7334
   Abstract »    Full Text »    PDF »
High stimulus unmasks positive feedback in an autoregulated bacterial signaling circuit.
T. Miyashiro and M. Goulian (2008)
PNAS 105, 17457-17462
   Abstract »    Full Text »    PDF »
Signal integration in bacterial two-component regulatory systems.
A. Y. Mitrophanov and E. A. Groisman (2008)
Genes & Dev. 22, 2601-2611
   Abstract »    Full Text »    PDF »
Overcoming H-NS-mediated Transcriptional Silencing of Horizontally Acquired Genes by the PhoP and SlyA Proteins in Salmonella enterica.
J. C. Perez, T. Latifi, and E. A. Groisman (2008)
J. Biol. Chem. 283, 10773-10783
   Abstract »    Full Text »    PDF »
A negative feedback loop involving small RNAs accelerates Vibrio cholerae's transition out of quorum-sensing mode.
S. L. Svenningsen, C. M. Waters, and B. L. Bassler (2008)
Genes & Dev. 22, 226-238
   Abstract »    Full Text »    PDF »
Anaplasma phagocytophilum p44 mRNA Expression Is Differentially Regulated in Mammalian and Tick Host Cells: Involvement of the DNA Binding Protein ApxR.
X. Wang, Z. Cheng, C. Zhang, T. Kikuchi, and Y. Rikihisa (2007)
J. Bacteriol. 189, 8651-8659
   Abstract »    Full Text »    PDF »
Crystal Structures of the Receiver Domain of the Response Regulator PhoP from Escherichia coli in the Absence and Presence of the Phosphoryl Analog Beryllofluoride.
P. Bachhawat and A. M. Stock (2007)
J. Bacteriol. 189, 5987-5995
   Abstract »    Full Text »    PDF »
A connector of two-component regulatory systems promotes signal amplification and persistence of expression.
A. Kato, A. Y. Mitrophanov, and E. A. Groisman (2007)
PNAS 104, 12063-12068
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)