Open AccessNitrogen status modulates the expression of RNA‐binding proteins in cyanobacteria
Author(s) -
Mori Shahram,
Castoreno Adam,
Mulligan Martin E.,
Lammers Peter J.
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00682-7
Subject(s) - cyanobacteria , rna binding protein , rna , protein expression , gene expression , biology , chemistry , bacteria , microbiology and biotechnology , biochemistry , genetics , gene
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.