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The bacterial signal molecule, ppGpp, regulates Salmonella virulence gene expression.
Mol Microbiol. 2004 Jun; 52(6):1827-44.MM

Abstract

Numerous, overlapping global regulatory systems mediate the environmental signalling controlling the virulence of Salmonella typhimurium. With both extra- and intracellular lifestyles, unravelling the mechanisms involved in regulating Salmonella pathogenesis has been complex. Here, we report a factor co-ordinating environmental signals with global regulators involved in pathogenesis. An S. typhimuriumDeltarelADeltaspoT strain deficient in guanosine tetraphosphate (ppGpp) synthesis was found to be highly attenuated in vivo and non-invasive in vitro. The DeltarelADeltaspoT strain exhibited severely reduced expression of hilA and invF, encoding major transcriptional activators required for Salmonella pathogenicity island 1 (SPI-1) gene expression and at least two other pathogenicity islands. None of the growth conditions intended to mimic the intestinal milieu was capable of inducing hilA expression in the absence of ppGpp. However, the expression of global regulators of Salmonella virulence, RpoS and PhoP/Q, and RpoS- and PhoP/Q-dependent, non-virulence-related genes was not significantly different from the wild-type strain. The results indicate that ppGpp plays a central role as a regulator of virulence gene expression in S. typhimurium and implicates ppGpp as a major factor in the environmental and host-dependent regulation of Salmonella pathogenesis.

Authors+Show Affiliations

Institut Pasteur, Unité Interactions Bactéries-Cellules, 28 Rue du Docteur Roux, F-75724 Cedex 15 Paris, France.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15186428

Citation

Pizarro-Cerdá, Javier, and Karsten Tedin. "The Bacterial Signal Molecule, ppGpp, Regulates Salmonella Virulence Gene Expression." Molecular Microbiology, vol. 52, no. 6, 2004, pp. 1827-44.
Pizarro-Cerdá J, Tedin K. The bacterial signal molecule, ppGpp, regulates Salmonella virulence gene expression. Mol Microbiol. 2004;52(6):1827-44.
Pizarro-Cerdá, J., & Tedin, K. (2004). The bacterial signal molecule, ppGpp, regulates Salmonella virulence gene expression. Molecular Microbiology, 52(6), 1827-44.
Pizarro-Cerdá J, Tedin K. The Bacterial Signal Molecule, ppGpp, Regulates Salmonella Virulence Gene Expression. Mol Microbiol. 2004;52(6):1827-44. PubMed PMID: 15186428.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The bacterial signal molecule, ppGpp, regulates Salmonella virulence gene expression. AU - Pizarro-Cerdá,Javier, AU - Tedin,Karsten, PY - 2004/6/10/pubmed PY - 2005/2/3/medline PY - 2004/6/10/entrez SP - 1827 EP - 44 JF - Molecular microbiology JO - Mol Microbiol VL - 52 IS - 6 N2 - Numerous, overlapping global regulatory systems mediate the environmental signalling controlling the virulence of Salmonella typhimurium. With both extra- and intracellular lifestyles, unravelling the mechanisms involved in regulating Salmonella pathogenesis has been complex. Here, we report a factor co-ordinating environmental signals with global regulators involved in pathogenesis. An S. typhimuriumDeltarelADeltaspoT strain deficient in guanosine tetraphosphate (ppGpp) synthesis was found to be highly attenuated in vivo and non-invasive in vitro. The DeltarelADeltaspoT strain exhibited severely reduced expression of hilA and invF, encoding major transcriptional activators required for Salmonella pathogenicity island 1 (SPI-1) gene expression and at least two other pathogenicity islands. None of the growth conditions intended to mimic the intestinal milieu was capable of inducing hilA expression in the absence of ppGpp. However, the expression of global regulators of Salmonella virulence, RpoS and PhoP/Q, and RpoS- and PhoP/Q-dependent, non-virulence-related genes was not significantly different from the wild-type strain. The results indicate that ppGpp plays a central role as a regulator of virulence gene expression in S. typhimurium and implicates ppGpp as a major factor in the environmental and host-dependent regulation of Salmonella pathogenesis. SN - 0950-382X UR - https://www.unboundmedicine.com/medline/citation/15186428/The_bacterial_signal_molecule_ppGpp_regulates_Salmonella_virulence_gene_expression_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0950-382X&date=2004&volume=52&issue=6&spage=1827 DB - PRIME DP - Unbound Medicine ER -