Regulation of Translation and mRNA Stability by Hfq-Binding Small RNAs in Escherichia coli

2009 ◽  
pp. 75-94
Keyword(s):  
Escherichia Coli ◽  
Mrna Stability ◽  
Small Rnas ◽  
Regulation Of Translation

scholarly journals σE Regulates and Is Regulated by a Small RNA in Escherichia coli

2007 ◽  
Vol 189 (11) ◽  
pp. 4243-4256 ◽  
Author(s):  
Karl M. Thompson ◽  
Virgil A. Rhodius ◽  
Susan Gottesman
Keyword(s):  
Escherichia Coli ◽  
Small Rnas ◽  
Noncoding Rna ◽  
Response Regulator ◽  
Heterologous Promoter ◽  
Genomic Libraries ◽  
Multicopy Suppressors ◽  
Intergenic Regions ◽  
Transposon Mutants

ABSTRACT RybB is a small, Hfq-binding noncoding RNA originally identified in a screen of conserved intergenic regions in Escherichia coli. Fusions of the rybB promoter to lacZ were used to screen plasmid genomic libraries and genomic transposon mutants for regulators of rybB expression. A number of plasmids, including some carrying rybB, negatively regulated the fusion. An insertion in the rep helicase and one upstream of dnaK decreased expression of the fusion. Multicopy suppressors of these insertions led to identification of two plasmids that stimulated the fusion. One contained the gene for the response regulator OmpR; the second contained mipA, encoding a murein hydrolase. The involvement of MipA and OmpR in cell surface synthesis suggested that the rybB promoter might be dependent on σE. The sequence upstream of the +1 of rybB contains a consensus σE promoter. The activity of rybB-lacZ was increased in cells lacking the RseA anti-sigma factor and when σE was overproduced from a heterologous promoter. The activity of rybB-lacZ and the detection of RybB were totally abolished in an rpoE-null strain. In vitro, σE efficiently transcribes from this promoter. Both a rybB mutation and an hfq mutation significantly increased expression of both rybB-lacZ and rpoE-lacZ fusions, consistent with negative regulation of the σE response by RybB and other small RNAs. Based on the plasmid screens, NsrR, a repressor sensitive to nitric oxide, was also found to negatively regulate σE-dependent promoters in an RseA-independent fashion.

Growth-rate dependent regulation of mRNA stability in Escherichia coli

Nature ◽  
1984 ◽  
Vol 312 (5989) ◽  
pp. 75-77 ◽  
Author(s):  
G. Nilsson ◽  
J. G. Belasco ◽  
S. N. Cohen ◽  
A. von Gabain
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Mrna Stability ◽  
Rate Dependent

scholarly journals Trans-Acting Small RNAs and Their Effects on Gene Expression in Escherichia coli and Salmonella enterica

EcoSal Plus ◽  
2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Jens Hör ◽  
Gianluca Matera ◽  
Jörg Vogel ◽  
Susan Gottesman ◽  
Gisela Storz
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Small Rnas ◽  
Expression In Escherichia Coli

scholarly journals Quorum Sensing in Escherichia coli Is Signaled by AI-2/LsrR: Effects on Small RNA and Biofilm Architecture

2007 ◽  
Vol 189 (16) ◽  
pp. 6011-6020 ◽  
Author(s):  
Jun Li ◽  
Can Attila ◽  
Liang Wang ◽  
Thomas K. Wood ◽  
James J. Valdes ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quorum Sensing ◽  
Small Rnas ◽  
Current Data ◽  
Extended Model ◽  
Cellular Functions ◽  
E Coli ◽  
Autoinducer 2 ◽  
Distinct Mechanism ◽  
First Time

ABSTRACT The regulatory network for the uptake of Escherichia coli autoinducer 2 (AI-2) is comprised of a transporter complex, LsrABCD; its repressor, LsrR; and a cognate signal kinase, LsrK. This network is an integral part of the AI-2 quorum-sensing (QS) system. Because LsrR and LsrK directly regulate AI-2 uptake, we hypothesized that they might play a wider role in regulating other QS-related cellular functions. In this study, we characterized physiological changes due to the genomic deletion of lsrR and lsrK. We discovered that many genes were coregulated by lsrK and lsrR but in a distinctly different manner than that for the lsr operon (where LsrR serves as a repressor that is derepressed by the binding of phospho-AI-2 to the LsrR protein). An extended model for AI-2 signaling that is consistent with all current data on AI-2, LuxS, and the LuxS regulon is proposed. Additionally, we found that both the quantity and architecture of biofilms were regulated by this distinct mechanism, as lsrK and lsrR knockouts behaved identically. Similar biofilm architectures probably resulted from the concerted response of a set of genes including flu and wza, the expression of which is influenced by lsrRK. We also found for the first time that the generation of several small RNAs (including DsrA, which was previously linked to QS systems in Vibrio harveyi) was affected by LsrR. Our results suggest that AI-2 is indeed a QS signal in E. coli, especially when it acts through the transcriptional regulator LsrR.

scholarly journals σ28-dependent small RNAs regulate timing of flagella biosynthesis

2021 ◽  
Author(s):  
Sahar Melamed ◽  
Aixia Zhang ◽  
Michal Jarnik ◽  
Joshua Mills ◽  
Hongen Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Transcriptional Regulation ◽  
Cell Motility ◽  
Sigma Factor ◽  
Small Rnas ◽  
Posttranscriptional Regulation ◽  
Bacterial Motility ◽  
Coding Sequences ◽  
Protein Levels ◽  
Opposing Effects

Flagella are important for bacterial motility as well as for pathogenesis. Synthesis of these structures is energy intensive and, while extensive transcriptional regulation has been described, little is known about the posttranscriptional regulation. Small RNAs (sRNAs) are widespread posttranscriptional regulators, most base pairing with mRNAs to affect their stability and/or translation. Here we describe four UTR-derived sRNAs (UhpU, MotR, FliX and FlgO) whose expression is controlled by the flagella sigma factor σ28 (fliA) in Escherichia coli. Interestingly, MotR and FliX have opposing effects on flagellin protein levels, flagella number and cell motility, with MotR accelerating flagella synthesis and FliX decelerating flagella synthesis. Unlike most sRNAs, MotR and FliX base pair within the coding sequences of target mRNAs. They also uniquely act on ribosomal protein mRNAs thus coordinating flagella synthesis with ribosome production. The study shows how sRNA-mediated regulation can overlay a complex network enabling nuanced control of flagella synthesis.

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