iBet uBet web content aggregator. Adding the entire web to your favor.
iBet uBet web content aggregator. Adding the entire web to your favor.



Link to original content: https://pubmed.ncbi.nlm.nih.gov/16199566/
Effect of RyhB small RNA on global iron use in Escherichia coli - PubMed Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2005 Oct;187(20):6962-71.
doi: 10.1128/JB.187.20.6962-6971.2005.

Effect of RyhB small RNA on global iron use in Escherichia coli

Eric Massé  1 , Carin K Vanderpool, Susan Gottesman
Affiliations

Effect of RyhB small RNA on global iron use in Escherichia coli

Eric Massé et al. J Bacteriol. 2005 Oct.

Abstract

RyhB is a noncoding RNA regulated by the Fur repressor. It has previously been shown to cause the rapid degradation of a number of mRNAs that encode proteins that utilize iron. Here we examine the effect of ectopic RyhB production on global gene expression by microarray analysis. Many of the previously identified targets were found, as well as other mRNAs encoding iron-binding proteins, bringing the total number of regulated operons to at least 18, encoding 56 genes. The two major operons involved in Fe-S cluster assembly showed different behavior; the isc operon appears to be a direct target of RyhB action, while the suf operon does not. This is consistent with previous findings suggesting that the suf genes but not the isc genes are important for Fe-S cluster synthesis under iron-limiting conditions, presumably for essential iron-binding proteins. In addition, we observed repression of Fur-regulated genes upon RyhB expression, interpreted as due to intracellular iron sparing resulting from reduced synthesis of iron-binding proteins. Our results demonstrate the broad effects of a single noncoding RNA on iron homeostasis.

PubMed Disclaimer

Figures

FIG. 1.
FIG. 1.
Northern blot analysis of RyhB levels in different bacterial backgrounds. The wild-type cells grown in the presence of the iron chelator 2,2′-dipyridyl (dip) at 250 μM express the small RNA RyhB from the endogenous gene. In comparison, the cells (ΔryhB::cat strain) carrying the pBAD-ryhB plasmid express the small RNA only from the arabinose-inducible pBAD promoter in the presence of 0.1% arabinose (ara). The difference in RyhB levels after 15 min of induction is about 10 times more in pBAD-ryhB plus ara than in wild type plus dip.
FIG. 2.
FIG. 2.
Northern blot analysis of time course effect of RyhB overproduction on exbBD and sodB mRNAs. fur+ and fur cells carrying the pBAD-ryhB plasmid were grown to an optical density at 600 nm of 0.5 and then treated with 0.1% arabinose (ara) to express RyhB. Total RNA was extracted at the indicated time by the hot phenol technique and probed for sodB or exbBD mRNAs with biotinylated oligonucleotides EM33 and EM120, respectively (for probe descriptions, see Materials and Methods). The EM12 probe hybridizes with the loading control 16S rRNA.
FIG. 3.
FIG. 3.
Model for indirect RyhB effect on Fur-regulated genes. RyhB causes rapid degradation of the target mRNAs it pairs with. In this model, the rapid block of synthesis of many iron-utilizing proteins increases intracellular levels of Fe (iron sparing), improving repression by Fur. After 15 min of RyhB expression, Fur-regulated mRNAs show a pattern of disappearance similar to those seen with RyhB-regulated genes. The loss of a RyhB effect in fur mutants supports the iron-sparing model.
See this image and copyright information in PMC

Comment in

  • Regulation by iron: RNA rules the rust.
    Kadner RJ. Kadner RJ. J Bacteriol. 2005 Oct;187(20):6870-3. doi: 10.1128/JB.187.20.6870-6873.2005. J Bacteriol. 2005. PMID: 16199555 Free PMC article. Review. No abstract available.

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Aiba, H., S. Adhya, and B. de Crombrugghe. 1981. Evidence for two functional gal promoters in intact Escherichia coli cells. J. Biol. Chem. 256:11905-11910. - PubMed
    1. Andrews, S. C., A. K. Robinson, and F. Rodriguez-Quinones. 2003. Bacterial iron homeostasis. FEMS Microbiol. Rev. 27:215-237. - PubMed
    1. Angerer, A., and V. Braun. 1998. Iron regulates transcription of the Escherichia coli ferric citrate transport genes directly and through the transcription initiation proteins. Arch. Microbiol. 169:483-490. - PubMed
    1. Baichoo, N., and J. D. Helmann. 2002. Recognition of DNA by Fur: a reinterpretation of the Fur box consensus sequence. J. Bacteriol. 184:5826-5832. - PMC - PubMed
    1. Braun, V., S. Mahren, and M. Ogierman. 2003. Regulation of the FecI-type ECF sigma factor by transmembrane signalling. Curr. Opin. Microbiol. 6:173-180. - PubMed

Publication types

MeSH terms

LinkOut - more resources