Nitrogen status modulates the expression of RNA-binding proteins in cyanobacteria

Shahram Mori, Adam Castoreno, Martin E. Mulligan, Peter J. Lammers

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Biochemical responses to cold and osmotic stresses overlap because each decreases the availability of free water. Since RNA-binding proteins are known to accumulate following cold stress and play key roles in regulating transcription termination, the effect of osmotic stress on expression of RNA-binding proteins was examined. The transcript levels of four genes encoding RNA-binding proteins (rbpA, rbpB, rbpC and rbpD) were monitored in Anabaena sp. PCC 7120 cultures supplemented with ammonium ions or growing under nitrogen-fixing conditions. Steady-state transcript levels of all four genes increased transiently in response to a temperature shift from 30 to 20°C under both nitrogen regimes. Osmotic stress also enhanced rbpB, rbpC and rbpD gene expression in ammonium grown cultures. In the absence of a combined nitrogen source, osmotic stress repressed the short-term induction of rbp gene expression. The accumulation of RNA-binding proteins did not follow transcript levels, but remained high 24 h after stress initiation. It is concluded that nitrogen nutrition modulates the stress-responsive regulation of RNA-binding proteins in cyanobacteria, providing a potential mechanism to integrate environmental and developmental signals.

Original languageEnglish (US)
Pages (from-to)203-210
Number of pages8
JournalFEMS Microbiology Letters
Volume227
Issue number2
DOIs
StatePublished - Oct 24 2003
Externally publishedYes

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Keywords

  • Anabaena 7120
  • Cold stress
  • Cyanobacterium
  • Nitrogen fixation
  • Osmotic stress
  • RNA-binding protein
  • Rbp
  • Salt stress
  • Transcription regulation

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology
  • Genetics

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