Consulta: creatorFacets:"Laurent, Sebastien"
Registros recuperados: 10
Data/hora: 06/06/2024 05:54:06

Toward in situ detection of algae species
Provedor de dados: 5
Autores: Colas, Florent; Laurent, Sebastien; Lehaitre, Michel; Hamelin, Muriel; Crassous, Marie-pierre; Antoine, Elisabeth; Dreanno, Catherine; Deuff, Albert; Compere, Chantal.
For the last few years there is a more and more pressing need to develop system for detecting HAB at their early stage. Researchers have then been working on new in situ sensor. In this paper a submarine transducer based on surface plasmon resonance is reported. It demonstrated a refractive index resolution of 3.10(-6), which is promising for later phytoplankton detection.
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00107/21802/20328.pdf

Toward Detection of Harmful Algae Blooms by in situ Surface Plasmon Resonance Spectroscopy
Provedor de dados: 5
Autores: Laurent, Sebastien; Colas, Florent; Hamelin, Muriel; Crassous, Marie-pierre; Antoine, Elisabeth; Lehaitre, Michel; Compere, Chantal.
Among marine algae species, Alexandrium minutum produces a phycotoxin called paralytic shellfish poisoning (PSP) that is introduced in the food chain through the ingestion of phytoplankton by shellfishs, and later by human consumers. Thus, in situ monitoring of A. minutum proliferation in coastal seawater is of great economical importance for marine resources exploitation. Here, we propose a rapid test for the detection of A. minutum by surface plasmon resonance spectroscopy. First, whole genomic DNA is extracted from the algae. Second, a 677 bp long portion of the 28S ribosomal DNA is amplified by PCR. Third, the PCR product is detected by surface plasmon resonance spectroscopy onto a DNA functionalized gold substrate.
Tipo: Text
Palavras-chave: PCR; Algal detection; In situ; Spectroscopy; Surface plasmon resonance.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6830.pdf

Differential Activities of DNA Polymerases in Processing Ribonucleotides during DNA Synthesis in Archaea
Provedor de dados: 5
Autores: Lemor, Melanie; Kong, Ziqing; Henry, Etienne; Brizard, Raphael; Laurent, Sebastien; Bosse, Audrey; Henneke, Ghislaine.
Consistent with the fact that ribonucleotides (rNTPs) are in excess over deoxyribonucleotides (dNTPs) in vivo, recent findings indicate that replicative DNA polymerases (DNA Pols) are able to insert ribonucleotides (rNMPs) during DNA synthesis, raising crucial questions about the fidelity of DNA replication in both Bacteria and Eukarya. Here, we report that the level of rNTPs is 20-fold higher than that of dNTPs in Pyrococcus abyssi cells. Using dNTP and rNTP concentrations present in vivo, we recorded rNMP incorporation in a template-specific manner during in vitro synthesis, with the family-D DNA Pol (PolD) having the highest propensity compared with the family-B DNA Pol and the p41/p46 complex. We also showed that ribonucleotides accumulate at a...
Tipo: Text
Palavras-chave: Archaea; DNA replication and repair; DNA polymerase; Nucleotide pool; Translesion synthesis.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00464/57603/59796.pdf

A surface plasmon resonance system for the underwater detection of domoic acid
Provedor de dados: 5
Autores: Colas, Florent; Crassous, Marie-pierre; Laurent, Sebastien; Litaker, Richard W.; Rinnert, Emmanuel; Le Gall, Erwan; Lunven, Michel; Delauney, Laurent; Compère, Chantal.
Over the past decade Surface Plasmon Resonance (SPR) techniques have been applied to the measurement of numerous analytes. In this article, an SPR biosensor system deployed from an oceanographic vessel was used to measure dissolved domoic acid (DA), a common and harmful phycotoxin produced by certain microalgae species belonging to the genus Pseudo-nitzschia. During the biosensor deployment, concentrations of Pseudo-nitzschia cells were very low over the study area and measured DA concentrations were below detection. However, the in situ operational detection limit of the system was established using calibrated seawater solutions spiked with DA. The system could detect the toxin at concentrations as low as 0.1 ng mL−1 and presented a linear dynamic range...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00324/43481/42921.pdf

Modelization of the regulation of protein synthesis following fertilization in sea urchin shows requirement of two processes: a destabilization of elF4E:4E-BP complex and a great stimulation of the 4E-BP-degradation mechanism, both rapamycin-sensitive
Provedor de dados: 5
Autores: Laurent, Sebastien; Richard, Adrien; Mulner-lorillon, Odile; Morales, Julia; Flament, Didier; Glippa, Virginie; Bourdon, Jeremie; Gosselin, Pauline; Siegel, Anne; Cormier, Patrick; Belle, Robert.
Fertilization of sea urchin eggs involves an increase in protein synthesis associated with a decrease in the amount of the translation initiation inhibitor 4E-BP A highly simple reaction model for the regulation of protein synthesis was built and was used to simulate the physiological changes in the total 4E-BP amount observed during time after fertilization. Our study evidenced that two changes occurring at fertilization are necessary to fit with experimental data. The first change was an 8-fold increase in the dissociation parameter (koffi) of the elF4E:4E-BP complex. The second was an important 32.5-fold activation of the degradation mechanism of the protein 4E-BP Additionally, the changes in both processes should occur in 5 min time interval...
Tipo: Text
Palavras-chave: Translational control; Sea urchin embryos; Mechanisms of fertilization; Deterministic model; Translation simulation.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00382/49341/49731.pdf

The Glycine-Rich Motif of Pyrococcus abyssi DNA Polymerase D Is Critical for Protein Stability
Provedor de dados: 5
Autores: Castrec, Benoit; Laurent, Sebastien; Henneke, Ghislaine; Flament, Didier; Raffin, Jean-paul.
A glycine-rich motif described as being involved in human polymerase 8 proliferating cell nuclear antigen (PCNA) binding has also been identified in all euryarchaeal DNA polymerase D (Pol D) family members. We redefined the motif as the (G)-PYF box. In the present study, Pol D (G)-PYF box motif mutants from Pyrococcus abyssi were generated to investigate its role in functional interactions with the cognate PCNA. We demonstrated that this motif is not essential for interactions between PabPol D (P. abyssi Pol D) and PCNA, using surface plasmon resonance and primer extension studies. Interestingly, the (G)-PYF box is located in a hydrophobic region close to the active site. The (G)-PYF box mutants exhibited altered DNA binding properties. In addition, the...
Tipo: Text
Palavras-chave: DNA replication DNA polymerase D; (G)-PYF box Archaea thermostability.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00002/11293/7879.pdf

Physical and functional interplay between PCNA DNA clamp and Mre11–Rad50 complex from the archaeon Pyrococcus furiosus
Provedor de dados: 5
Autores: Hogrel, Gaelle; Lu, Yang; Laurent, Sebastien; Henry, Etienne; Etienne, Clarisse; Duy Khanh Phung,; Dulermo, Remi; Bosse, Audrey; Pluchon, Pierre Francois; Clouet-d'Orval, Beatrice; Flament, Didier.
Several archaeal species prevalent in extreme environments are particularly exposed to factors likely to cause DNA damages. These include hyperthermophilic archaea (HA), living at temperatures &gt;70°C, which arguably have efficient strategies and robust genome guardians to repair DNA damage threatening their genome integrity. In contrast to Eukarya and other archaea, homologous recombination appears to be a vital pathway in HA, and the Mre11–Rad50 complex exerts a broad influence on the initiation of this DNA damage response process. In a previous study, we identified a physical association between the Proliferating Cell Nuclear Antigen (PCNA) and the Mre11–Rad50 (MR) complex. Here, by performing co-immunoprecipitation and SPR analyses, we identified a...
Tipo: Text
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00439/55092/56534.pdf

An Extended Network of Genomic Maintenance in the Archaeon Pyrococcus abyssi Highlights Unexpected Associations between Eucaryotic Homologs
Provedor de dados: 5
Autores: Pluchon, Pierre Francois; Fouqueau, Thomas; Creze, Christophe; Laurent, Sebastien; Briffotaux, Julien; Hogrel, Gaelle; Palud, Adeline; Henneke, Ghislaine; Godfroy, Anne; Hausner, Winfried; Thomm, Michael; Nicolas, Jacques; Flament, Didier.
In Archaea, the proteins involved in the genetic information processing pathways, including DNA replication, transcription, and translation, share strong similarities with those of eukaryotes. Characterizations of components of the eukaryotic-type replication machinery complex provided many interesting insights into DNA replication in both domains. In contrast, DNA repair processes of hyperthermophilic archaea are less well understood and very little is known about the intertwining between DNA synthesis, repair and recombination pathways. The development of genetic system in hyperthermophilic archaea is still at a modest stage hampering the use of complementary approaches of reverse genetics and biochemistry to elucidate the function of new candidate DNA...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00171/28198/26556.pdf

New Approach For The Detection Of Toxic Algae Species
Provedor de dados: 5
Autores: Colas, Florent; Crassous, Marie-pierre; Laurent, Sebastien; Dreanno, Catherine; Compere, Chantal.
Up to now, toxic species are monitored by expensive and time-consuming laboratory analysis of seawater samples: after a 24h decantation, the samples are observed with an optical microscope and the cell concentration per species is determined. In this context, systems able to detect HAB species directly underwater would be of great help. An assay based on an SPR biosensor was then developed for detecting Alexandrium minutum.
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00089/19995/17658.pdf

RNA processing machineries in Archaea: the 5′-3′ exoribonuclease aRNase J of the β-CASP family is engaged specifically with the helicase ASH-Ski2 and the 3′-5′ exoribonucleolytic RNA exosome machinery
Provedor de dados: 5
Autores: Phung, Duy Khanh; Etienne, Clarisse; Batista, Manon; Langendijk-genevaux, Petra; Moalic, Yann; Laurent, Sebastien; Liuu, Sophie; Morales, Violette; Jebbar, Mohamed; Fichant, Gwennaele; Bouvier, Marie; Flament, Didier; Clouet-d’orval, Béatrice.
A network of RNA helicases, endoribonucleases and exoribonucleases regulates the quantity and quality of cellular RNAs. To date, mechanistic studies focussed on bacterial and eukaryal systems due to the challenge of identifying the main drivers of RNA decay and processing in Archaea. Here, our data support that aRNase J, a 5′-3′ exoribonuclease of the β-CASP family conserved in Euryarchaeota, engages specifically with a Ski2-like helicase and the RNA exosome to potentially exert control over RNA surveillance, at the vicinity of the ribosome. Proteomic landscapes and direct protein–protein interaction analyses, strengthened by comprehensive phylogenomic studies demonstrated that aRNase J interplay with ASH-Ski2 and a cap exosome subunit. Finally,...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00610/72250/71056.pdf