Sensing Starvation: A Homoserine Lactone-Dependent Signaling Pathway in Escherichia coli
Abstract
When nutrients become limiting, many bacteria differentiate and become resistant to environmental stresses. For Escherichia coli, this process is mediated by the σ^s subunit of RNA polymerase. Expression of σ^s was induced by homoserine lactone, a metabolite synthesized from intermediates in threonine biosynthesis. Homoserine lactone-dependent synthesis of σ^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.
- Publication:
-
Science
- Pub Date:
- July 1994
- DOI:
- 10.1126/science.7545940
- Bibcode:
- 1994Sci...265..537H