scholarly journals RNA‐binding protein Hfq downregulates locus of enterocyte effacement‐encoded regulators independent of small regulatory RNA in enterohemorrhagic Escherichia coli

2021 ◽  
Author(s):  
Naoki Sudo ◽  
Ken‐ichi Lee ◽  
Yasuhiko Sekine ◽  
Makoto Ohnishi ◽  
Sunao Iyoda
Keyword(s):  
Escherichia Coli ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Enterohemorrhagic Escherichia Coli ◽  
Regulatory Rna ◽  
Small Regulatory Rna ◽  
Enterocyte Effacement

scholarly journals The RNA Binding Protein CsrA Is a Pleiotropic Regulator of the Locus of Enterocyte Effacement Pathogenicity Island of Enteropathogenic Escherichia coli

2009 ◽  
Vol 77 (9) ◽  
pp. 3552-3568 ◽  
Author(s):  
Shantanu Bhatt ◽  
Adrianne Nehrling Edwards ◽  
Hang Thi Thu Nguyen ◽  
Didier Merlin ◽  
Tony Romeo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Host Cells ◽  
Flagellar Motility ◽  
Enterocyte Effacement ◽  
Pedestal Formation

ABSTRACT The attaching and effacing (A/E) pathogen enteropathogenic Escherichia coli (EPEC) forms characteristic actin-filled membranous protrusions upon infection of host cells termed pedestals. Here we examine the role of the RNA binding protein CsrA in the expression of virulence genes and proteins that are necessary for pedestal formation. The csrA mutant was defective in forming actin pedestals on epithelial cells and in disrupting transepithelial resistance across polarized epithelial cells. Consistent with reduced pedestal formation, secretion of the translocators EspA, EspB, and EspD and the effector Tir was substantially reduced in the csrA mutant. Purified CsrA specifically bound to the sepL espADB mRNA leader, and the corresponding transcript levels were reduced in the csrA mutant. In contrast, Tir synthesis was unaffected in the csrA mutant. Reduced secretion of Tir appeared to be in part due to decreased synthesis of EscD, an inner membrane architectural protein of the type III secretion system (TTSS) and EscF, a protein that forms the protruding needle complex of the TTSS. These effects were not mediated through the locus of enterocyte effacement (LEE) transcriptional regulator GrlA or Ler. In contrast to the csrA mutant, multicopy expression of csrA repressed transcription from LEE1, grlRA, LEE2, LEE5, escD, and LEE4, an effect mediated by GrlA and Ler. Consistent with its role in other organisms, CsrA also regulated flagellar motility and glycogen levels. Our findings suggest that CsrA governs virulence factor expression in an A/E pathogen by regulating mRNAs encoding translocators, effectors, or transcription factors.

scholarly journals Positive regulation of motility and flhDC expression by the RNA-binding protein CsrA of Escherichia coli

2001 ◽  
Vol 40 (1) ◽  
pp. 245-256 ◽  
Author(s):  
Bangdong L. Wei ◽  
Anne-Marie Brun-Zinkernagel ◽  
Jerry W. Simecka ◽  
Birgit M. Prüß ◽  
Paul Babitzke ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Positive Regulation

scholarly journals Genetic identification of the functional surface for RNA binding by Escherichia coli ProQ

2020 ◽  
Vol 48 (8) ◽  
pp. 4507-4520 ◽  
Author(s):  
Smriti Pandey ◽  
Chandra M Gravel ◽  
Oliver M Stockert ◽  
Clara D Wang ◽  
Courtney L Hegner ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Site Directed Mutagenesis ◽  
Genetic Identification ◽  
Messenger Rnas ◽  
Functional Surface

Abstract The FinO-domain-protein ProQ is an RNA-binding protein that has been known to play a role in osmoregulation in proteobacteria. Recently, ProQ has been shown to act as a global RNA-binding protein in Salmonella and Escherichia coli, binding to dozens of small RNAs (sRNAs) and messenger RNAs (mRNAs) to regulate mRNA-expression levels through interactions with both 5′ and 3′ untranslated regions (UTRs). Despite excitement around ProQ as a novel global RNA-binding protein, and its potential to serve as a matchmaking RNA chaperone, significant gaps remain in our understanding of the molecular mechanisms ProQ uses to interact with RNA. In order to apply the tools of molecular genetics to this question, we have adapted a bacterial three-hybrid (B3H) assay to detect ProQ’s interactions with target RNAs. Using domain truncations, site-directed mutagenesis and an unbiased forward genetic screen, we have identified a group of highly conserved residues on ProQ’s NTD as the primary face for in vivo recognition of two RNAs, and propose that the NTD structure serves as an electrostatic scaffold to recognize the shape of an RNA duplex.

scholarly journals Solution structure of the antitermination protein NusB of Escherichia coli: a novel all-helical fold for an RNA-binding protein

1998 ◽  
Vol 17 (14) ◽  
pp. 4092-4100 ◽  
Author(s):  
Martin Huenges ◽  
Christian Rölz ◽  
Ruth Gschwind ◽  
Ralph Peteranderl ◽  
Fabian Berglechner ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Solution Structure ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein

A novel small regulatory RNA enhances cell motility in enterohemorrhagic Escherichia coli

2014 ◽  
Vol 60 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Naoki Sudo ◽  
Akiko Soma ◽  
Akira Muto ◽  
Sunao Iyoda ◽  
Mayumi Suh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Motility ◽  
Enterohemorrhagic Escherichia Coli ◽  
Regulatory Rna ◽  
Small Regulatory Rna

scholarly journals The RNA-binding protein Hfq assembles into foci-like structures in nitrogen starved Escherichia coli

2020 ◽  
Vol 295 (35) ◽  
pp. 12355-12367
Author(s):  
Josh McQuail ◽  
Amy Switzer ◽  
Lynn Burchell ◽  
Sivaramesh Wigneshweraraj
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Adaptive Response ◽  
Rna Binding ◽  
Nitrogen Starvation ◽  
Binding Protein ◽  
Regulatory Protein ◽  
Rna Binding Protein ◽  
E Coli

The initial adaptive responses to nutrient depletion in bacteria often occur at the level of gene expression. Hfq is an RNA-binding protein present in diverse bacterial lineages that contributes to many different aspects of RNA metabolism during gene expression. Using photoactivated localization microscopy and single-molecule tracking, we demonstrate that Hfq forms a distinct and reversible focus-like structure in Escherichia coli specifically experiencing long-term nitrogen starvation. Using the ability of T7 phage to replicate in nitrogen-starved bacteria as a biological probe of E. coli cell function during nitrogen starvation, we demonstrate that Hfq foci have a role in the adaptive response of E. coli to long-term nitrogen starvation. We further show that Hfq foci formation does not depend on gene expression once nitrogen starvation has set in and occurs indepen-dently of the transcription factor N-regulatory protein C, which activates the initial adaptive response to N starvation in E. coli. These results serve as a paradigm to demonstrate that bacterial adaptation to long-term nutrient starvation can be spatiotemporally coordinated and can occur independently of de novo gene expression during starvation.

scholarly journals The Protease Lon and the RNA-Binding Protein Hfq Reduce Silencing of the Escherichia coli bgl Operon by H-NS

2004 ◽  
Vol 186 (9) ◽  
pp. 2708-2716 ◽  
Author(s):  
Sudhanshu Dole ◽  
Yvonne Klingen ◽  
V. Nagarajavel ◽  
Karin Schnetz
Keyword(s):  
Escherichia Coli ◽  
Transcription Initiation ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Specific Effect ◽  
Receptor Protein ◽  
Coding Region ◽  
Genes Encoding ◽  
Pleiotropic Regulators

ABSTRACT The histone-like nucleoid structuring protein H-NS represses the Escherichia coli bgl operon at two levels. H-NS binds upstream of the promoter, represses transcription initiation, and binds downstream within the coding region of the first gene, where it induces polarity of transcription elongation. In hns mutants, silencing of the bgl operon is completely relieved. Various screens for mutants in which silencing of bgl is reduced have yielded mutations in hns and in genes encoding the transcription factors LeuO and BglJ. In order to identify additional factors that regulate bgl, we performed a transposon mutagenesis screen for mutants in which silencing of the operon is strengthened. This screen yielded mutants with mutations in cyaA, hfq, lon, and pgi, encoding adenylate cyclase, RNA-binding protein Hfq, protease Lon, and phosphoglucose isomerase, respectively. In cyaA mutants, the cyclic AMP receptor protein-dependent promoter is presumably inactive. The specific effect of the pgi mutants on bgl is low. Interestingly, in the hfq and lon mutants, the downstream silencing of bgl by H-NS (i.e., the induction of polarity) is more efficient, while the silencing of the promoter by H-NS is unaffected. Furthermore, in an hns mutant, Hfq has no significant effect and the effect of Lon is reduced. These data provide evidence that the specific repression by H-NS can (directly or indirectly) be modulated and controlled by other pleiotropic regulators.

scholarly journals rsmC of the Soft-Rotting Bacterium Erwinia carotovora subsp. carotovora Negatively Controls Extracellular Enzyme and HarpinEcc Production and Virulence by Modulating Levels of Regulatory RNA (rsmB) and RNA-Binding Protein (RsmA)

1999 ◽  
Vol 181 (19) ◽  
pp. 6042-6052 ◽  
Author(s):  
Yaya Cui ◽  
Asita Mukherjee ◽  
C. Korsi Dumenyo ◽  
Yang Liu ◽  
Arun K. Chatterjee
Keyword(s):  
Extracellular Enzymes ◽  
Rna Binding ◽  
Binding Protein ◽  
Regulatory Gene ◽  
Rna Binding Protein ◽  
Extracellular Enzyme ◽  
Erwinia Carotovora ◽  
Homoserine Lactone ◽  
Regulatory Rna ◽  
Knockout Mutant

ABSTRACT Previous studies have shown that the production of extracellular enzymes (pectate lyase [Pel], polygalacturonase [Peh], cellulase [Cel], and protease [Prt]) and harpinEcc (the elicitor of hypersensitive reaction) in Erwinia carotovora subsp.carotovora is regulated by RsmA, an RNA-binding protein, and rsmB, a regulatory RNA (Rsm stands for regulator of secondary metabolites) (Y. Liu et al., Mol. Microbiol. 29:219–234, 1998). We have cloned and characterized a novel regulatory gene,rsmC, that activates RsmA production and represses extracellular enzyme and harpinEcc production,rsmB transcription, and virulence in E. carotovora subsp. carotovora. In anrsmC knockout mutant of E. carotovora subsp.carotovora Ecc71 carrying the chromosomal copy of the wild-type rsmA + allele, the basal levels of Pel, Peh, Cel, Prt, and harpinEcc as well as the amounts ofrsmB, pel-1, peh-1,celV, and hrpNEcc transcripts are high, whereas the levels of rsmA transcripts and RsmA protein are low. Furthermore, the expression of anrsmA-lacZ gene fusion is lower in the RsmC−mutant than in the RsmC+ parent. Conversely, the expression of an rsmB-lacZ operon fusion is higher in the RsmC− mutant than in the RsmC+ parent. These observations establish that RsmC negatively regulates rsmBtranscription but positively affects RsmA production. Indeed, comparative studies with an RsmC− mutant, an RsmA− mutant, and an RsmA− RsmC−double mutant have revealed that the negative effects on exoprotein production and virulence are due to the cumulative regulatory effects of RsmC on rsmA and rsmB. Exoprotein production by the RsmC− mutant is partially dependent on the quorum sensing signal,N-(3-oxohexanoyl)-l-homoserine lactone. Southern blot data and analysis of PCR products disclosed the presence of rsmC sequences in E. carotovora subsp. atroseptica, E. carotovora subsp. betavasculorum, and E. carotovora subsp. carotovora. These findings collectively support the idea that rsmA andrsmB expression in these plant pathogenicErwinia species is controlled by RsmC or a functional homolog of RsmC.

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