The interactions of numerous regulatory small RNAs (sRNAs) with target mRNAs have been characterized, but how sRNAs can regulate multiple, structurally unrelated is less understood. Here we show that Salmonella GcvB sRNA directly acts on seven commonly encode periplasmic substrate-binding proteins ABC uptake systems for amino acids and peptides. Alignment homologs distantly related bacteria revealed a conserved G/U-rich element strictly required recognition. Analysis gene fusion regulation...

Regardless of their targets and modes action, subinhibitory concentrations antibiotics can have an impact on cell physiology trigger a large variety cellular responses in different bacterial species. Subinhibitory β-lactam cause reactive oxygen species production induce PolIV-dependent mutagenesis Escherichia coli. Here we show that the RpoS regulon. RpoS-regulon induction is required for because it diminishes control DNA-replication fidelity by depleting MutS E. coli, Vibrio cholerae...

This paper shows that the small RNA MicA (previously SraD) is an antisense regulator of ompA in Escherichia coli . accumulates upon entry into stationary phase and down-regulates level mRNA. Regulation (outer membrane protein A), previously attributed to Hfq/mRNA binding, lost deletion micA gene, whereas overexpression inhibits synthesis OmpA. In vitro, binds mRNA leader. Enzymatic chemical probing was used map structures MicA, leader, complex formed binding. binding generates a footprint...

MicroRNAs (miRNAs) are a recently discovered category of small RNA molecules that regulate gene expression at the post-transcriptional level. Accumulating evidence indicates miRNAs aberrantly expressed in variety human cancers and revealed to be oncogenic play pivotal role initiation progression these pathologies. It is now clear inhibition miRNAs, defined as blocking their biosynthesis or function, could find an application therapy different types cancer which implicated. Here we report...

One of the major limitations use phosphodiester oligonucleotides in cells is their rapid degradation by nucleases. To date, several chemical modifications have been employed to overcome this issue but insufficient efficacy and/or specificity limited vivo usefulness. In work conformationally restricted nucleotides, locked nucleic acid (LNA), were investigated design nuclease resistant aptamers targeted against HIV‐1 TAR RNA. LNA/DNA chimeras synthesized from a shortened version hairpin RNA...

Abstract Background MicroRNAs, post-transcriptional regulators of eukaryotic gene expression, are implicated in host defense against pathogens. Viruses and bacteria have evolved strategies that suppress microRNA functions, resulting a sustainable infection. In this work we report Helicobacter pylori , human stomach-colonizing bacterium responsible for severe gastric inflammatory diseases cancers, downregulates an embryonic stem cell cluster proliferating epithelial cells to achieve cycle...

Chronic Helicobacter pylori infection provokes an inflammation of the gastric mucosa, at high risk for ulcer and cancer development. The most virulent strains harbor cag pathogenicity island (cagPAI) encoding a type 4 secretion system, which allows delivery bacterial effectors into epithelial cells, inducing pro-inflammatory responses phenotypic alterations reminiscent epithelial-to-mesenchymal transition (EMT). This study characterizes EMT features in H. pylori-infected investigates their...

Protein complexes directing messenger RNA (mRNA) degradation are present in all kingdoms of life. In Escherichia coli, mRNA is performed by an degradosome organized the major ribonuclease RNase E. bacteria lacking E, existence a functional still open question. Here, we report that bacterial pathogen Helicobacter pylori, directed minimal consisting Hp-RNase J and only DExD-box helicase H. RhpA. We show protein complex promotes faster double-stranded vitro comparison with alone. The ATPase...

Abstract MicroRNAs (miRNAs) are a recently discovered category of small RNA molecules that regulate gene expression at the post‐transcriptional level. Accumulating evidence indicates miRNAs aberrantly expressed in variety human cancers and inhibition these oncogenic could find application therapy different types cancer. Herein, we describe synthesis biological evaluation new small‐molecule drugs target production. In particular, chose to two (i.e., miRNA‐372 ‐373) implicated various cancer,...

MicroRNAs are key factors in the regulation of gene expression and their deregulation has been directly linked to various pathologies such as cancer. The use small molecules tackle overexpression oncogenic miRNAs proved its efficacy holds promise for therapeutic applications. Here we describe screening a 640-compound library identification polyamine derivatives interfering with vitro Dicer-mediated processing miR-372 precursor (pre-miR-372). most active inhibitor is spermine-amidine...

Aptamers interacting with RNA hairpins through loop−loop (so-called kissing) interactions have been described as an alternative to antisense oligomers for the recognition of hairpins. R06, aptamer, was previously shown form a kissing complex TAR (trans-activating responsive) hairpin HIV-1 (Ducongé and Toulmé (1999) 5, 1605). We derived chimeric locked nucleic acid (LNA)/DNA aptamer from R06 that retains binding properties originally selected aptamer. demonstrated this LNA/DNA competes...

Type I toxin-antitoxin (TA) systems have been identified in a wide range of bacterial genomes. Here, we report the characterization new type TA system present on chromosome major human gastric pathogen, Helicobacter pylori. We show that aapA1 gene encodes 30 amino acid peptide whose artificial expression H. pylori induces cell death. The synthesis this toxin is prevented by transcription an antitoxin RNA, named IsoA1, expressed opposite strand gene. further reveal additional layers...

Neomycin–nucleobase–amino acid conjugates bind to pre-miR-372 and inhibit Dicer-mediated processing thus leading decreased levels of oncogenic miR-372 <italic>in vitro</italic> in gastric adenocarcinoma cells.

The interaction of the TAR RNA element human immunodeficiency virus type 1 (HIV-1) with a 2'-O-methyl analogue an hairpin aptamer previously identified by in vitro selection [Ducongé, F., and Toulmé, J. (1999) 5, 1605−1614] was characterized UV-monitored thermal denaturation surface plasmon resonance experiments. complex between this derivative displays stability (Kd = 9.9 ± 1.0 nM) kinetic properties [kon 9.0 0.3 M-1 s-1, koff (8.9 0.6) × 10-4 s-1] close to those parent aptamer. modified...

Degradation of RNA as an intermediate message between genes and corresponding proteins is important for rapid attenuation gene expression maintenance cellular homeostasis. This process controlled by ribonucleases that have different target specificities. In the bacterial pathogen Helicobacter pylori, exo- endoribonuclease RNase J essential growth. To explore role in H. we identified its putative targets at a global scale using next generation sequencing. We found strong depletion led to...

A hairpin RNA aptamer has been identified by in vitro selection against the transactivation-responsive element (TAR) of HIV-1. nuclease-resistant N3′ → P5′ phosphoramidate isosequential analog this also folds as a and forms with TAR loop–loop “kissing” complex binding constant low nanomolar range demonstrated electrophoretic mobility-shift assays surface plasmon resonance experiments. The key structural determinants, which contribute to stability aptamer–TAR complex, loop complementarity GA...

MicroRNAs regulate eukaryotic gene expression upon pairing onto target mRNAs. This targeting is influenced by the complementarity between microRNA "seed" sequence at its 5′ end and seed-matching sequences in mRNA. Here, we assess efficiency specificity of 8-mer locked nucleic acid (LNA)-modified oligonucleotides raised against seeds miR-372 miR-373, two embryonic stem cell-specific microRNAs prominently expressed human gastric adenocarcinoma AGS cell line. Provided that perfect over all...

Type I toxin–antitoxin (T1TA) systems constitute a large class of genetic modules with antisense RNA (asRNA)-mediated regulation gene expression. They are widespread in bacteria and consist an mRNA coding for toxic protein noncoding asRNA that acts as antitoxin preventing the synthesis toxin by directly base-pairing to its cognate mRNA. The co- post-transcriptional T1TA is intimately linked sequence structure, therefore it essential have accurate annotation molecules understand this...

In most bacteria, ribosomal RNA is transcribed as a single polycistronic precursor that first processed by RNase III. This double-stranded specific cleaves two large stems flanking the 23S and 16S rRNA mature sequences, liberating three 16S, 5S precursors, which are further other ribonucleases. Here, we investigate maturation pathway of human gastric pathogen Helicobacter pylori. bacterium has an unusual arrangement its genes, gene being separated from 23S-5S cluster. We show III also...