MicA sRNA links the PhoP regulon to cell envelope stress

Numerous small RNAs regulators of gene expression exist in bacteria. A large class of them binds to the RNA chaperone Hfq and act by base pairing interactions with their target mRNA, thereby affecting their translation and/or stability. They often have multiple direct targets, some of which may be r...

Full description

Saved in:
Bibliographic Details
Published in:Molecular microbiology 2010-04, Vol.76 (2), p.467-479
Main Authors: Coornaert, Audrey, Lu, Alisa, Mandin, Pierre, Springer, Mathias, Gottesman, Susan, Guillier, Maude
Format: Article
Language:English
Subjects:
Bacterial Proteins - antagonists & inhibitors
Bacterial Proteins - biosynthesis
Biochemistry, Molecular Biology
Biological and medical sciences
Cell Membrane - metabolism
Cell Wall - metabolism
Cells
E coli
Escherichia coli - physiology
Escherichia coli Proteins - antagonists & inhibitors
Escherichia coli Proteins - biosynthesis
Fundamental and applied biological sciences. Psychology
Gene expression
Gene Expression Regulation, Bacterial
Genes
Life Sciences
Microbiology
MicroRNAs - metabolism
Mitochondria
Protein Biosynthesis
Regulon
Ribonucleic acid
RNA
RNA, Messenger - metabolism
Stress, Physiological
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Numerous small RNAs regulators of gene expression exist in bacteria. A large class of them binds to the RNA chaperone Hfq and act by base pairing interactions with their target mRNA, thereby affecting their translation and/or stability. They often have multiple direct targets, some of which may be regulators themselves, and production of a single sRNA can therefore affect the expression of dozens of genes. We show in this study that the synthesis of the Escherichia coli pleiotropic PhoPQ two-component system is repressed by MicA, a σE-dependent sRNA regulator of porin biogenesis. MicA directly pairs with phoPQ mRNA in the translation initiation region of phoP and presumably inhibits translation by competing with ribosome binding. Consequently, MicA downregulates several members of the PhoPQ regulon. By linking PhoPQ to σE, our findings suggest that major cellular processes such as Mg²⁺ transport, virulence, LPS modification or resistance to antimicrobial peptides are modulated in response to envelope stress. In addition, we found that Hfq strongly affects the expression of phoP independently of MicA, raising the possibility that even more sRNAs, which remain to be identified, could regulate PhoPQ synthesis.
ISSN:0950-382X
1365-2958
DOI:10.1111/j.1365-2958.2010.07115.x