A5004830802- RNA and protein synthesis mechanisms
- RNA Research and Splicing
- RNA modifications and cancer
- Genomics and Chromatin Dynamics
- Fungal and yeast genetics research
- Plant nutrient uptake and metabolism
- DNA Repair Mechanisms
- Peptidase Inhibition and Analysis
- Plant Molecular Biology Research
- Plant Micronutrient Interactions and Effects
- Ubiquitin and proteasome pathways
- Microtubule and mitosis dynamics
- Plant Stress Responses and Tolerance
- CRISPR and Genetic Engineering
- Microbial Metabolic Engineering and Bioproduction
- Chromosomal and Genetic Variations
- Viral Infectious Diseases and Gene Expression in Insects
- Nuclear Structure and Function
- Telomeres, Telomerase, and Senescence
- Epigenetics and DNA Methylation
- Diffusion and Search Dynamics
- Plant Gene Expression Analysis
- Lipid metabolism and biosynthesis
- Genetics, Aging, and Longevity in Model Organisms
- Light effects on plants
Université de Toulouse
2007-2025
Centre National de la Recherche Scientifique
2007-2025
Université Toulouse III - Paul Sabatier
2022-2025
University of Geneva
2016-2025
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2024
Centre de Biologie du Développement
2024
Institut de Génétique, Environnement et Protection des Plantes
2014-2024
Laboratoire de Microbiologie et Génétique Moléculaires
2024
Institute of Genetics
2019
Laboratoire de Biologie Moléculaire des Eucaryotes
2011-2013
Chromosome dynamics are recognized to be intimately linked genomic transactions, yet the physical principles governing spatial fluctuations of chromatin still a matter debate. Using high-throughput single-particle tracking, we recorded movements nine fluorescently labeled chromosome loci located on chromosomes III, IV, XII, and XIV Saccharomyces cerevisiae over an extended temporal range spanning more than four orders magnitude (10 −2 –10 3 sec). Spatial appear characterized by anomalous...
Ribosome biogenesis is a complex and energy-demanding process requiring tight coordination of ribosomal RNA (rRNA) protein (RP) production. Given the extremely high level RP synthesis in rapidly growing cells, alteration any step ribosome assembly may impact growth by leading to proteotoxic stress. Although transcription factor Hsf1 has emerged as central regulator proteostasis, how its activity coordinated with unknown. Here, we show that arrest budding yeast Saccharomyces cerevisiae...
RNA polymerase I (Pol I) produces large ribosomal RNAs (rRNAs). In this study, we show that the Rpa49 and Rpa34 Pol subunits, which do not have counterparts in II III complexes, are functionally conserved using heterospecific complementation of human Schizosaccharomyces pombe orthologues Saccharomyces cerevisiae. Deletion RPA49 leads to disappearance nucleolar structure, but assembly can be restored by decreasing gene copy number from 190 25. Statistical analysis Miller spreads absence...
Large amounts of nitrogen (N) fertilizers are used in the production oilseed rape. However, as low-input methods crop management introduced crops will need to withstand temporary N deficiency. In temperate areas, rape also be affected by frequent drought periods. Here we evaluated physiological and metabolic impact nitrate limitation on response water deprivation. Different fertilizer were applied plants at vegetative stage, which then deprived rehydrated. Both depletion accelerated leaf...
The yeast Sfp1 protein regulates both cell division and growth but how it coordinates these processes is poorly understood. We demonstrate that directly controls genes required for ribosome production many other growth-promoting processes. Remarkably, the complete set of target revealed only by a combination ChIP (chromatin immunoprecipitation) ChEC endogenous cleavage) methods, which uncover two promoter binding modes, one requiring cofactor DNA-recognition motif. Glucose-regulated at cycle...
Rpa34 and Rpa49 are nonessential subunits of RNA polymerase I, conserved in species from Saccharomyces cerevisiae Schizosaccharomyces pombe to humans. bound an N-terminal region a two-hybrid assay was lost rpa49 mutant lacking this Rpa34-binding domain, whereas rpa34Δ weakened the binding polymerase. mutants were caffeine sensitive, mutation lethal top1Δ rpa14Δ, rpa135(L656P), rpa135(D395N) mutants. These defects shared by rpa49Δ mutants, suppressed overexpression Rpa49, thus, presumably...
Ribosome biogenesis is a major metabolic effort for growing cells. In Saccharomyces cerevisiae, Hmo1, an abundant high-mobility group box protein (HMGB) binds to the coding region of RNA polymerase I transcribed ribosomal RNAs genes and promoters ∼70% genes. this study, we have demonstrated functional conservation eukaryotic HMGB proteins involved in DNA (rDNA) transcription. We shown that when expressed budding yeast, human UBF1 newly identified Sp-Hmo1 (Schizosaccharomyces pombe) localize...
Abstract While expression of ribosomal protein genes (RPGs) in the budding yeast has been extensively studied, a longstanding enigma persists regarding their co-regulation under fluctuating growth conditions. Most RPG promoters display one two distinct arrangements core set transcription factors (TFs) and are further differentiated by presence or absence HMGB Hmo1. However, third group appears not to be bound any these proteins, raising question how whole suite is co-regulated. We...
Chromosomes architecture is viewed as a key component of gene regulation, but principles chromosomal folding remain elusive. Here we used high-throughput live cell microscopy to characterize the conformation and dynamics longest chromosome Saccharomyces cerevisiae (XII). Chromosome XII carries ribosomal DNA (rDNA) that defines nucleolus, major hallmark nuclear organization. We determined intranuclear positions 15 loci distributed every ∼100 kb along chromosome, investigated their motion over...
The Ccr4-Not complex is mostly known as the major eukaryotic deadenylase. However, several studies have uncovered roles of complex, in particular Not subunits, unrelated to deadenylation and relevant for translation. In particular, existence condensates that regulate translation elongation dynamics has been reported. Typical evaluate efficiency rely on soluble extracts obtained after disruption cells ribosome profiling. Yet cellular mRNAs can be actively translated may not present such extracts.
Abstract The RNA exosome is a multiprotein complex essential for maturation and degradation. In budding yeast, nine-subunit protein (Exo9) associated with Rrp44 forms Exo10 in the cytoplasm and, Rrp6, Exo11 nucleus. Depending on its subcellular localization, interacts different cofactors substrates. cytoplasm, associates SKI via Ski7, while nucleus, TRAMP complex. Within nucleolus, participates ribosomal (rRNA) processing, facilitated by Mtr4-dependent adaptors Utp18 Nop53. this manuscript,...
The Rif1 protein is a negative regulator of DNA replication initiation in eukaryotes. Here we show that budding yeast inhibits at the rDNA locus. Absence Rif1, or disruption its interaction with PP1/Glc7 phosphatase, leads to more intensive replication. effect Rif1-Glc7 on similar Sir2 deacetylase, and two would appear act same pathway, since rif1Δ sir2Δ double mutant shows no further increase Loss activity also accompanied by an repeat instability again not additive sir2Δ. We find,...
Replication forks temporarily or terminally pause at hundreds of hard-to-replicate regions around the genome. A conserved pair budding yeast replisome components Tof1-Csm3 (fission Swi1-Swi3 and human TIMELESS-TIPIN) act as a "molecular brake" promote fork slowdown proteinaceous replication barriers (RFBs), while accessory helicase Rrm3 assists in removing protein obstacles. Here we show that complex promotes pausing independently by recruiting topoisomerase I (Top1) to replisome....
The early steps of large-ribosomal-subunit assembly feature among the least understood ribosome synthesis in eukaryotes. In Saccharomyces cerevisiae, box C/D chaperone small nucleolar ribonucleoprotein (snoRNP) snR190 and Npa1 complex, composed α-solenoid scaffold proteins Npa2, DEAD-box helicase Dbp6, RNA-binding protein Nop8, Rsa3, are likely involved 25S ribosomal RNA (rRNA) folding events. Here, we report for first time existence outside pre-ribosomal particles an independent...
Acetylation of histone H3 at residue K9 (H3K9ac) is a dynamically regulated mark associated with transcriptionally active promoters in eukaryotes. However, our understanding the relationship between H3K9ac and gene expression remains mostly correlative. In this study, we identify large suite growth-related (GR) genes yeast that undergo particularly strong down-regulation both transcription promoter-associated upon stress, delineate roles transcriptional activators (TAs), repressors, SAGA...
The RNA exosome is a multiprotein complex essential for maturation and degradation. In budding yeast, nine-subunit protein (Exo9) associated with Rrp44 forms Exo10 in the cytoplasm and, Rrp6, Exo11 nucleus. Depending on its subcellular localization, interacts different cofactors substrates. cytoplasm, associates SKI via Ski7, while nucleus, TRAMP complex. Within nucleolus, participates ribosomal (rRNA) processing, facilitated by Mtr4-dependent adaptors Utp18 Nop53. this manuscript, we have...
Nutrient abundance boosts ribosome biogenesis, whereas dormancy factors limit degradation upon starvation. The equilibrium between the two pathways governs cell growth. In this study, we identified suppressor of Tom1 (Stm1) as a molecular link protection and biogenesis in Saccharomyces cerevisiae. While Stm1 was previously described factor, show that it activates Ifh1, transcriptional activator ribosomal protein genes. transiently localizes to nucleolus, where interacts with pre-ribosomes...
Ribosomal RNA (rRNA) production represents the most active transcription in cell. Synthesis of large rRNA precursors (35-47S) can be achieved by up to 150 polymerase I (Pol I) enzymes simultaneously transcribing each gene. In this paper, we present recent advances made understanding regulatory mechanisms that control elongation. Built-in Pol elongation factors, such as Rpa34/Rpa49 budding yeast and PAF53/CAST humans, are instrumental extremely high rate per intrinsically linked chromatin...
Abstract Intrinsically disordered regions (IDRs) are highly enriched in the nucleolar proteome but their physiological role ribosome assembly remains poorly understood. Our study reveals functional plasticity of extremely abundant lysine-rich IDRs small ribonucleoprotein particles (snoRNPs) from protists to mammalian cells. We show Saccharomyces cerevisiae that electrostatic properties this IDR, KKE/D domain, promote snoRNP accumulation vicinity nascent rRNAs, facilitating modification....
Ribosomes are ribozymes, hence correct folding of the rRNAs during ribosome biogenesis is crucial to ensure catalytic activity. RNA helicases, which can modulate RNA-RNA and RNA/protein interactions, proposed participate in rRNA tridimensional folding. Here, we analyze biochemical properties Dbp6, a DEAD-box helicase required for conversion initial 90S pre-ribosomal particle into first pre-60S particle. We demonstrate that vitro, Dbp6 shows ATPase as well annealing clamping activities...