Sensing starvation: a homoserine lactone--dependent signaling pathway in Escherichia coli.
When nutrients become limiting, many bacteria differentiate and become resistant to environmental stresses. For Escherichia coli, this process is mediated by the sigma s subunit of RNA polymerase. Expression of sigma s was induced by homoserine lactone, a metabolite synthesized from intermediates in threonine biosynthesis. Homoserine lactone-dependent synthesis of sigma s was prevented by overexpression of a newly identified protein, RspA. The function of homoserine lactone derivatives in many cell density-dependent phenomena and the similarity of RspA to a Streptomyces ambofaciens protein suggest that synthesis of homoserine lactone may be a general signal of starvation.
Huisman
G W
GW
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115.
Kolter
R
R
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008954:Models, Biological; D008969:Molecular Sequence Data; D009876:Operon; D010641:Phenotype; D012808:Sigma Factor / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction; D014158:Transcription, Genetic; D014733:Vibrio / Q000235:genetics
D001426:Bacterial Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; C088386:homoserine lactone; D002374:Catalase; D015107:4-Butyrolactone