A5065701072- RNA and protein synthesis mechanisms
- RNA Research and Splicing
- RNA modifications and cancer
- Bacterial Genetics and Biotechnology
- Fungal and yeast genetics research
- Bacteriophages and microbial interactions
- Viral Infections and Immunology Research
- DNA and Nucleic Acid Chemistry
- Mitochondrial Function and Pathology
- RNA regulation and disease
- DNA Repair Mechanisms
- Plant Virus Research Studies
- Plant and Fungal Interactions Research
- CRISPR and Genetic Engineering
- Gene Regulatory Network Analysis
- Soft tissue tumors and treatment
- Sarcoma Diagnosis and Treatment
- Evolution and Genetic Dynamics
- Tuberculosis Research and Epidemiology
- Monoclonal and Polyclonal Antibodies Research
- Multilingual Education and Policy
- Genomics and Chromatin Dynamics
- Cancer-related molecular mechanisms research
- Language, Linguistics, Cultural Analysis
- Plant Disease Resistance and Genetics
Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes
1995-2024
Université Claude Bernard Lyon 1
2009-2024
Centre National de la Recherche Scientifique
2007-2024
Institut de Biologie Physico-Chimique
2008-2024
Sorbonne Université
1994-2024
Université Paris Cité
2005-2012
Expression Génétique Microbienne
2006-2012
Assistance Publique – Hôpitaux de Paris
2001
National Institute of Diabetes and Digestive and Kidney Diseases
1998-1999
National Institutes of Health
1999
Ribonucleases J1 and J2 are recently discovered enzymes with dual 5'-to-3' exoribonucleolytic/endoribonucleolytic activity that plays a key role in the maturation degradation of Bacillus subtilis RNAs. RNase is essential, while its paralogue not. Up to now, it had generally been assumed two functioned independently. Here we present evidence RNases form complex likely be predominant these wild-type cells. While both J1/J2 have robust exoribonuclease vitro, has at least orders magnitude weaker...
From genetic and biochemical evidence, we previously proposed that S15 inhibits its own translation by binding to mRNA in a region overlapping the ribosome loading site. This was postulated stabilize pseudoknot structure exists equilibrium with two stem-loops. Here, use "toeprint" experiments Moloney murine leukemia virus reverse transcriptase analyze effect of on formation ternary mRNA-30S-tRNA(fMet) complex. We show 30S subunit stops near position +10, corresponding 3' terminus pseudoknot,...
Abstract Metallo‐β‐lactamases (MBLs) cause resistance of Gram‐negative bacteria to β‐lactam antibiotics and are serious concern, because they can inactivate the last‐resort carbapenems MBL inhibitors clinical value still lacking. We previously identified original binding mode 4‐amino‐2,4‐dihydro‐5‐(2‐methylphenyl)‐3 H ‐1,2,4‐triazole‐3‐thione (compound IIIA) within dizinc active site L1 MBL. Herein we present crystallographic structure a complex with corresponding non‐amino compound IIIB...
Abstract The No-Go Decay (NGD) mRNA surveillance pathway degrades mRNAs containing stacks of stalled ribosomes. Although an endoribonuclease has been proposed to initiate cleavages upstream the stall sequence, production two RNA fragments resulting from a unique cleavage never demonstrated. Here we use expressing 3′-ribozyme produce truncated transcripts in vivo mimic naturally occurring known trigger NGD. This technique allows us analyse endonucleolytic events at single-nucleotide...
Proverbs play a very important role in any cultural society such as to inform, caution, and inspire people their daily lives, among others. Generation after generation, proverbs have endured, offering insights direction that still find meaningful date. This research, is concentrating on the numerous approaches, which were employed by translators Dorothy Kweyu Fortunatus F. Kawegere translate Siku Njema Ken Walibora. research highlights several approaches used translation process, including...
The discovery of the essential ribonuclease RNase J1, involved in global mRNA decay Bacillus subtilis, has paved way for studies on turnover pathways specific RNAs this organism. Here we report an effect J1 depletion both maturation and degradation hbs mRNA, encoding B. subtilis orthologue histone-like protein HU. major transcript observed wild-type cells is generated by blocking 5'-to-3' exonuclease activity ribosomes initiating translation mRNA. Increasing strength Shine-Dalgarno (SD)...
Approximately 30 copies of the Ty1 retrotransposon are present in genome Saccharomyces cerevisiae. Previous studies gave insights into global regulation transcription but provided no information on behavior individual genomic elements. This work shows that expression 31 elements S288C varies over a 50-fold range. Their is repressed by chromatin structures, which antagonized Swi/Snf and SAGA chromatin-modifying complexes highly expressed These carry five potential Gcn4 binding sites their...
We mapped and cloned SKI6 of Saccharomyces cerevisiae, a gene that represses the copy number L-A double-stranded RNA virus, found it encodes an essential 246-residue protein with homology to tRNA-processing enzyme, RNase PH. The ski6-2 mutant expressed electroporated non-poly(A) luciferase mRNAs 8- 10-fold better than did isogenic wild type. No effect on expression uncapped or normal was found. Kinetics synthesis direct measurement radiolabeled mRNA indicate primary Ski6p efficiency...
The scavenger decapping enzyme Dcs1 has been shown to facilitate the activity of cytoplasmic 5'-3' exoribonuclease Xrn1 in eukaryotes. also be required for growth glycerol medium. We therefore wondered whether capacity activate RNA degradation could account its requirement on this carbon source. Indeed, a catalytic mutant is unable grow medium, and removal nuclear localization signal Rat1, homolog Xrn1, restores growth. A essential yeast glycerol, suggesting that activation by...
Transcriptome analyses have revealed that convergent gene transcription can produce many 3′-overlapping mRNAs in diverse organisms. Few studies examined the fate of 3′-complementary double-stranded RNA-dependent nuclear phenomena, and nothing is known about cytoplasmic destiny messengers or their impact on expression. Here, we demonstrate complementary tails interact cytoplasm promote post-transcriptional regulatory events including no-go decay (NGD) Saccharomyces cerevisiae. Genome-wide...
ABSTRACT We mapped and cloned SKI7 , a gene that negatively controls the copy number of L-A M double-stranded RNA viruses in Saccharomyces cerevisiae . found it encodes nonessential 747-residue protein with similarities to two translation factors, Hbs1p EF1-α. The ski7 mutant was hypersensitive hygromycin B, result also suggesting role translation. product repressed expression nonpolyadenylated [non-poly(A)] mRNAs, whether capped or uncapped, thus explaining why Ski7p inhibits propagation...
Previous experiments revealed that DHH1, a RNA helicase involved in the regulation of mRNA stability and translation, complemented phenotype Saccharomyces cerevisiae mutant affected expression genes coding for monocarboxylic-acids transporters, JEN1 ADY2 (Paiva S, Althoff Casal M, Leao C. FEMS Microbiol Lett, 1999, 170∶301–306). In wild type cells, had been shown to be undetectable presence glucose or formic acid, induced lactate. this work, we show accumulates dhh1 mutant, when acid was...
The identification of RNases or RNase effectors is a continuous challenge, particularly given the current importance RNAs in control genome expression. Here, we show that fluorogenic RNA–DNA hybrid powerful tool for real-time fluorescence detection and assay exoribonucleases (RT-FeDEx). This RT-FeDEx provides new strategy isolation, purification, known unknown exoribonucleases.
Viroids are small pathogenic circular single-stranded RNAs, present in two complementary sequences, named plus and minus, infected plant cells. A high degree of complementarities between different regions the RNAs allows them to adopt complex structures. Since viroids naked non-coding interactions with host factors appear be closely related their structural catalytic characteristics. Avocado sunblotch viroid (ASBVd), a member family Avsunviroidae, replicates via symmetric RNA-dependant...
The ribosomal protein S15 from Escherichia coli binds to a pseudoknot in its own messenger. This interaction is an essential step the mechanism of translational autoregulation. In previous study, recognition determinant for autoregulation, involving U⋅G wobble pair, was located center stem I pseudoknot. this extensive mutagenesis analysis has been conducted and around pair by comparing effects these mutations on expression level S15. results show that cannot be substituted A⋅G, C⋅A, A⋅C,...
After deadenylation, most cytoplasmic mRNAs are decapped and digested by 5′ to 3′ exonucleases in Saccharomyces cerevisiae . Capped deadenylated degraded a lesser extent exonucleases. We have used method, based on the electroporation of vitro synthetised mRNAs, study relative importance these two exonucleolytic pathways under stress conditions. show that derepression GCN4 upon amino acid starvation specifically limits 5′-to-3′-degradation pathway. Because adenosine 3′-5′ biphosphate (pAp),...
Previous experiments showed that S15 inhibits its own translation by binding to mRNA in a region overlapping the ribosome loading site. This was postulated stabilize pseudoknot structure exists equilibrium with two stem-loops and trap on site transitory state. In this study, we investigated effect of mutations translational operator on: protein S15, formation 30S/mRNA/tRNA Mett ternary initiation complex, ability inhibit complex. The results were compared vivo expression repression rates....
Summary Expression of rpsO , the gene encoding small ribosomal protein S15, is autoregulated at translational level by which binds to its mRNA in a region overlapping ribosome‐binding site. By measuring effect mutations on expression rpsO‐lacZ fusion and S15 binding affinity for operator, formation pseudoknot operator site vivo fully demonstrated appears be prerequisite binding. The mutational analysis suggests also that specific determinants are located very limited regions structure formed...
Convergent gene pairs can produce transcripts with complementary sequences. We had shown that mRNA duplexes form in vivo Saccharomyces cerevisiae via interactions of overlapping 3'-ends and lead to posttranscriptional regulatory events. Here we show duplex formation is restricted convergent genes separated by short intergenic distance, independently their 3'-untranslated region (UTR) length. disclose an enrichment involved biological processes related stress among these genes. They are...