Globin-expression postpones onset of stationary phase specific gene expression in Escherichia coli

Research output: Contribution to journalArticle

Abstract

We have analyzed gene expression of Escherichia coli MG1655 expressing native and engineered bacterial globin proteins, in order to identify the molecular mechanisms leading to the improved phenotypical traits relative to control cells under oxygen-limited conditions. Regulated expression of hemoglobin and flavohemoglobin proteins postponed the onset of rpoS expression relative to plasmid bearing control cells. This change in expression pattern coincided with the expression pattern of stationary-phase specific genes including sigma(S)-dependent and sigma(S)-independent genes. Furthermore, several genes known to affect rpoS transcription, rpoS mRNA stability and sigma(S) turnover were regulated in such a manner as to ultimately lower the cellular level of sigma(S) in all globin-expressing strains. In a strain harboring an rpoS-lacZ fusion, lacZ expression correlated with acetate accumulation, a metabolite that is known to activate rpoS transcription, but not with growth. Therefore, we hypothesize that reduced excretion of acetate in globin expressing cells prevents induction of stationary phase specific genes. Additionally, several genes responding to carbon starvation (e.g. csrAB, cstA, sspA) were expressed at lower levels in globin-expressing cells. These findings are in good agreement with previous reports showing a more efficient energy household, i.e. also reduced glucose consumption, in hemoglobin- and flavohemoglobin-expressing cells relative to controls. (c) 2007 Elsevier B.V. All rights reserved.

Details

Authors
  • Alexander D. Frey
  • Charlotte Andersson
  • Vinzenz H. Schmid
  • Leif Bülow
  • Pauli T. Kallio
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biochemistry and Molecular Biology

Keywords

  • Ralstonia eutropha flavohemoprotein, oxygen-limited growth, Vitreoscilla hemoglobin, expression profiling, stationary phase
Original languageEnglish
Pages (from-to)461-471
JournalJournal of Biotechnology
Volume129
Issue number3
Publication statusPublished - 2007
Publication categoryResearch
Peer-reviewedYes