Regulation of Lipid A Modifications by Salmonella typhimurium Virulence Genes phoP-phoQ

Science  11 Apr 1997:
Vol. 276, Issue 5310, pp. 250-253
DOI: 10.1126/science.276.5310.250

You are currently viewing the abstract.

View Full Text

Via your Institution

Log in through your institution

Log in through your institution


Bacterial pathogenesis requires proteins that sense host microenvironments and respond by regulating virulence gene transcription. For Salmonellae, one such regulatory system is PhoP-PhoQ, which regulates genes required for intracellular survival and resistance to cationic peptides. Analysis by mass spectrometry revealed that Salmonella typhimurium PhoP-PhoQ regulated structural modifications of lipid A, the host signaling portion of lipopolysaccharide (LPS), by the addition of aminoarabinose and 2-hydroxymyristate. Structurally modified lipid A altered LPS-mediated expression of the adhesion molecule E-selectin by endothelial cells and tumor necrosis factor–α expression by adherent monocytes. Thus, altered responses to environmentally induced lipid A structural modifications may represent a mechanism for bacteria to gain advantage within host tissues.

  • * These authors contributed equally to this report.

  • To whom correspondence should be addressed. E-mail: millersi{at}

View Full Text

Cited By...