A cka-gfp transcriptional fusion reveals that the colicin K activity gene is induced in only 3 percent of the population

J Bacteriol. 2003 Jan;185(2):654-9. doi: 10.1128/JB.185.2.654-659.2003.

Abstract

In prokaryotes, only a few examples of differential gene expression in cell populations have been described. Colicin production in natural populations of Escherichia coli, while providing a competitive advantage in the natural habitat, also leads to lysis of the toxin-producing cell. Colicin K synthesis has been found to be induced due to an increase in ppGpp (I. Kuhar, J. P. van Putten, D. Zgur-Bertok, W. Gaastra, and B. J. Jordi, Mol. Microbiol. 41:207-216). Using two transcriptional fusions, cka-gfp and cki-gfp, we show that at the single-cell level, the colicin K activity gene cka is expressed in only 3% of the bacterial population upon induction by nutrient starvation. In contrast, the immunity gene cki is expressed in the large majority of the cells. Expression of the cka-gfp fusion in a lexA-defective strain and in a relA spoT mutant strain indicates that differential expression of cka is established primarily at the level of transcription.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Colicins / genetics*
  • Colicins / metabolism
  • Colicins / pharmacology
  • Escherichia coli / drug effects
  • Escherichia coli / genetics
  • Escherichia coli / growth & development*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Green Fluorescent Proteins
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins / genetics
  • Serine Endopeptidases / genetics
  • Transcription, Genetic*

Substances

  • Bacterial Proteins
  • Colicins
  • Escherichia coli Proteins
  • LexA protein, Bacteria
  • Luminescent Proteins
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Green Fluorescent Proteins
  • Serine Endopeptidases