Bibliographies thématiques / Eukaryotic plasmid

Littérature scientifique sur le sujet « Eukaryotic plasmid »

Auteur : Grafiati
Publié le 25 mai 2024

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Articles de revues sur le sujet "Eukaryotic plasmid"

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Jankowski, Jacek M., Eva Walczyk et Gordon H. Dixon. « Functional prokaryotic gene control signals within a eukaryotic rainbow trout protamine promoter ». Bioscience Reports 5, no 6 (1 juin 1985) : 453–61. http://dx.doi.org/10.1007/bf01116942.

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Following the construction of a series of pSV2-cat derived plasmids containing the chloramphenicol acetyltransferase (CAT) gene under the control of a eukaryotic trout protamine promoter, it was noted thatEscherichia coli, transformed with these plasmids, developed resistance to chloramphenicol (CM). This result suggested that the eukaryotic trout protamine promoter possessed significant prokaryotic promoter activity. Modification of the trout protamine promoter region by removing the region containing the eukaryotic Goldberg-Hogness box in the plasmid p525-cat increased the expression of the CAT gene almost to the wild-type level and conferred strong CM resistance. Sequence comparisons of the plasmid series indicate that prokaryotic promoter elements are present in the trout protamine promoter and that their similarity to the prokaryotic promoter consensus sequences and the distance between the two elements is more favourable in p525-cat, the plasmid which conlers the greatest CM resistance.
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Møller-Jensen, Jakob, et Kenn Gerdes. « Plasmid segregation : spatial awareness at the molecular level ». Journal of Cell Biology 179, no 5 (26 novembre 2007) : 813–15. http://dx.doi.org/10.1083/jcb.200710192.

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In bacteria, low-copy number plasmids ensure their stable inheritance by partition loci (par), which actively distribute plasmid replicates to each side of the cell division plane. Using time-lapse fluorescence microscopic tracking of segregating plasmid molecules, a new study provides novel insight into the workings of the par system from Escherichia coli plasmid R1. Despite its relative simplicity, the plasmid partition spindle shares characteristics with the mitotic machinery of eukaryotic cells.
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Soler, Nicolas, Marie Gaudin, Evelyne Marguet et Patrick Forterre. « Plasmids, viruses and virus-like membrane vesicles from Thermococcales ». Biochemical Society Transactions 39, no 1 (19 janvier 2011) : 36–44. http://dx.doi.org/10.1042/bst0390036.

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Several families of plasmids and viruses (PVs) have now been described in hyperthermophilic archaea of the order Thermococcales. One family of plasmids replicates by the rolling circle mechanism, whereas most other PVs probably replicate by the θ mode. PVs from Thermococcales encode novel families of DNA replication proteins that have only detectable homologues in other archaeal PVs. PVs from different families share a common gene pool and co-evolve with their hosts. Most Thermococcales also produce virus-like membrane vesicles similar to eukaryotic microparticles (ectosomes). Some membrane vesicles of Thermococcus nautilus harbour the plasmid pTN1, suggesting that vesicles can be involved in plasmid transfer between species.
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Vernis, Laurence, Marion Chasles, Philippe Pasero, Andrée Lepingle, Claude Gaillardin et Philippe Fournier. « Short DNA Fragments without Sequence Similarity Are Initiation Sites for Replication in the Chromosome of the YeastYarrowia lipolytica ». Molecular Biology of the Cell 10, no 3 (mars 1999) : 757–69. http://dx.doi.org/10.1091/mbc.10.3.757.

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We have previously shown that both a centromere (CEN) and a replication origin are necessary for plasmid maintenance in the yeastYarrowia lipolytica ( Vernis et al., 1997 ). Because of this requirement, only a small number of centromere-proximal replication origins have been isolated fromYarrowia. We used a CEN-based plasmid to obtain noncentromeric origins, and several new fragments, some unique and some repetitive sequences, were isolated. Some of them were analyzed by two-dimensional gel electrophoresis and correspond to actual sites of initiation (ORI) on the chromosome. We observed that a 125-bp fragment is sufficient for a functionalORI on plasmid, and that chromosomal origins moved to ectopic sites on the chromosome continue to act as initiation sites. These Yarrowia origins share an 8-bp motif, which is not essential for origin function on plasmids. The Yarrowiaorigins do not display any obvious common structural features, like bent DNA or DNA unwinding elements, generally present at or near eukaryotic replication origins. Y. lipolytica origins thus share features of those in the unicellular Saccharomyces cerevisiae and in multicellular eukaryotes: they are discrete and short genetic elements without sequence similarity.
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Capozzo, Alejandra V. E., Virginia Pistone Creydt, Graciela Dran, Gabriela Fernández, Sonia Gómez, Leticia V. Bentancor, Carolina Rubel, Cristina Ibarra, Martín Isturiz et Marina S. Palermo. « Development of DNA Vaccines against Hemolytic-Uremic Syndrome in a Murine Model ». Infection and Immunity 71, no 7 (juillet 2003) : 3971–78. http://dx.doi.org/10.1128/iai.71.7.3971-3978.2003.

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ABSTRACT Shiga toxin type 2 (Stx2) produced by Escherichia coli O:157H7 can cause hemolytic-uremic syndrome in children, a disease for which there is neither a vaccine nor an effective treatment. This toxin consists of an enzymatically active A subunit and a pentameric B subunit responsible for the toxin binding to host cells, and also found to be immunogenic in rabbits. In this study we developed eukaryotic plasmids expressing the B subunit gene of Stx2 (pStx2B) and the B subunit plus the gene coding for the A subunit with an active-site deletion (pStx2ΔA). Transfection of eukaryotic cells with these plasmids produced proteins of the expected molecular weight which reacted with specific monoclonal antibodies. Newborn and adult BALB/c mice immunized with two intramuscular injections of each plasmid, either alone or together with the same vector expressing the granulocyte and monocyte colony-stimulating factor (pGM-CSF), elicited a specific Th1-biased humoral response. The effect of pGM-CSF as an adjuvant plasmid was particularly notable in newborn mice and in pStx2B-vaccinated adult mice. Stx2-neutralizing activity, evaluated in vitro on VERO cell monolayers, correlated with in vivo protection. This is the first report using plasmids to induce a neutralizing humoral immune response against the Stx2.
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Liu, Binbo, Shengwu Liu, Xueju Qu et Junyan Liu. « Construction of a eukaryotic expression system for granulysin and its protective effect in mice infected with Mycobacterium tuberculosis ». Journal of Medical Microbiology 55, no 10 (1 octobre 2006) : 1389–93. http://dx.doi.org/10.1099/jmm.0.46706-0.

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A full-length cDNA of granulysin was inserted into the pcDNA3.1(−) vector to construct a eukaryotic expression plasmid for granulysin. The recombinant plasmids were injected intramuscularly into mice infected with Mycobacterium tuberculosis to evaluate the protective effect of granulysin. Granulysin significantly decreased the weight index (WI) of the spleen, reduced the numbers of viable bacteria in lung and spleen, and reduced the lesions of lung tissue in granulysin-rDNA-immunized mice compared with those of control group mice. In vitro, the serum of the recombinant-plasmid-immunized mice inhibited the viability of M. tuberculosis by the physical disruption of cell membranes. Therefore, granulysin has a therapeutic effect against M. tuberculosis.
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Xiao, Shan, Yanping Wang, Yuwen Ma, Jue Liu, Can’e Tang, Aiping Deng et Chunxiang Fang. « Dimethylation of eEF1A at Lysine 55 Plays a Key Role in the Regulation of eEF1A2 on Malignant Cell Functions of Acute Myeloid Leukemia ». Technology in Cancer Research & ; Treatment 19 (1 janvier 2020) : 153303382091429. http://dx.doi.org/10.1177/1533033820914295.

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Objective: This study aimed to explore whether eukaryotic translation elongation factor 1 alpha 2 affected cell proliferation, migration, and apoptosis via regulating the dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 in acute myeloid leukemia. Methods: The expressions of eukaryotic translation elongation factor 1 alpha 2 and dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 in acute myeloid leukemia cell lines and human normal bone marrow mononuclear cells (as control) were assessed. Control CRISPR-Cas9 lentivirus, eukaryotic translation elongation factor 1 alpha 2 knockout CRISPR-Cas9 lentivirus, vector plasmid, eukaryotic translation elongation factor 1 alpha 2 wild type overexpression plasmid, and eukaryotic translation elongation factor 1 alpha 2 with a K55R substitution overexpression plasmid were transfected into AML-193 and Kasumi-1 cells combined or alone, and were accordingly divided into 4 groups (Sgcontrol + vector group, SgeEF1A2 + vector group, SgeEF1A2 + eEF1A2WT group, and SgeEFIA2 + eEF1A2K55R group). Results: Eukaryotic translation elongation factor 1 alpha 2 and dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 expressions were higher in AML-193, Kasumi-1, and KG-1 cell lines compared to the control. In AML-193 and Kasumi-1 cells, the knockout and compensated experiments revealed that eukaryotic translation elongation factor 1 alpha 2 promoted cell proliferation and migration but repressed apoptosis. Additionally, the knockout of eukaryotic translation elongation factor 1 alpha 2 decreased dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 expression, meanwhile, eukaryotic translation elongation factor 1 alpha 2 wild type overexpression enhanced while eukaryotic translation elongation factor 1 alpha 2 with a K55R substitution overexpression did not influence the dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 expression. Furthermore, eukaryotic translation elongation factor 1 alpha 2 wild type overexpression promoted cell proliferation, enhanced migration, and decreased apoptosis, but eukaryotic translation elongation factor 1 alpha 2 with a K55R substitution overexpression did not influence these cellular functions in AML-193 and Kasumi-1 cells, suggesting the implication of dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 in eukaryotic translation elongation factor 1 alpha 2 mediated oncogenesis of acute myeloid leukemia. Conclusion: Eukaryotic translation elongation factor 1 alpha 2 and its dimethylated product may serve as therapeutic targets, and these findings may provide support for exploring novel strategies in acute myeloid leukemia treatment.
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Ma, Chien-Hui, Deepanshu Kumar, Makkuni Jayaram, Santanu K. Ghosh et Vishwanath R. Iyer. « The selfish yeast plasmid exploits a SWI/SNF-type chromatin remodeling complex for hitchhiking on chromosomes and ensuring high-fidelity propagation ». PLOS Genetics 19, no 10 (9 octobre 2023) : e1010986. http://dx.doi.org/10.1371/journal.pgen.1010986.

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Extra-chromosomal selfish DNA elements can evade the risk of being lost at every generation by behaving as chromosome appendages, thereby ensuring high fidelity segregation and stable persistence in host cell populations. The yeast 2-micron plasmid and episomes of the mammalian gammaherpes and papilloma viruses that tether to chromosomes and segregate by hitchhiking on them exemplify this strategy. We document for the first time the utilization of a SWI/SNF-type chromatin remodeling complex as a conduit for chromosome association by a selfish element. One principal mechanism for chromosome tethering by the 2-micron plasmid is the bridging interaction of the plasmid partitioning proteins (Rep1 and Rep2) with the yeast RSC2 complex and the plasmid partitioning locus STB. We substantiate this model by multiple lines of evidence derived from genomics, cell biology and interaction analyses. We describe a Rep-STB bypass system in which a plasmid engineered to non-covalently associate with the RSC complex mimics segregation by chromosome hitchhiking. Given the ubiquitous prevalence of SWI/SNF family chromatin remodeling complexes among eukaryotes, it is likely that the 2-micron plasmid paradigm or analogous ones will be encountered among other eukaryotic selfish elements.
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Luo, Ben-yan, Xiang-ming Chen, Min Tang, Feng Chen et Zhi Chen. « Construction of a eukaryotic expression plasmid of Humanin ». Journal of Zhejiang University SCIENCE 6B, no 1 (janvier 2005) : 11–13. http://dx.doi.org/10.1631/jzus.2005.b0011.

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Bao, G. Y., K. Y. Lu, S. F. Cui et L. Xu. « DKK1 eukaryotic expression plasmid and expression product identification ». Genetics and Molecular Research 14, no 2 (2015) : 6312–18. http://dx.doi.org/10.4238/2015.june.11.5.

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Thèses sur le sujet "Eukaryotic plasmid"

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Yull, Fiona Elizabeth. « Replication and regulation of the 2 micron plasmid of yeast ». Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253479.

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Hasan, Uzma Ayesha. « Construction, characterization and humoral responses to eukaryotic plasmid expressing the VZV qE antigen ». Thesis, Queen Mary, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322810.

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Mills, Anthony David. « The use of a plasmid maintenance system to control eukaryotic cell survival and proliferation ». Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619947.

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Girard, Fabien. « Tethering of molecular parasites on inactive chromatin in eukaryote nucleus ». Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS661.

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Les plasmides naturels sont courants chez les procaryotes, mais peu ont été documentés chez les eucaryotes. Le plasmide naturel 2µ présent dans la levure bourgeonnante Saccharomyces cerevisiae est l'un des mieux caractérisés. Cet élément génétique très stable coexiste avec son hôte depuis des millions d'années, ségrégeant efficacement à chaque division cellulaire par un mécanisme qui reste mal compris. En utilisant la ligature de proximité (Hi-C, Micro-C) pour cartographier les contacts entre le plasmide 2µ et les chromosomes de levure dans des dizaines de conditions biologiques différentes, nous avons constaté que le plasmide 2µ se fixe préférentiellement sur des régions à faible activité transcriptionnelle, correspondant souvent à de longs gènes inactifs. Les acteurs communs de la structure des chromosomes, tels que les membres des complexes de maintenance structurale des chromosomes (SMC), ne sont pas impliqués dans ces contacts qui dépendent plutôt d'un signal nucléosomique associé à une déplétion de l'ARN Pol II. Ces contacts sont stables tout au long du cycle cellulaire et peuvent être établis en quelques minutes. Cette stratégie peut aussi être trouvée dans d'autres types de molécules d'ADN et d'autres espèces que S. cerevisiae, comme le suggère le schéma de liaison du plasmide naturel le long des régions silencieuses des chromosomes de Dictyostelium discoideum
Natural plasmids are common in prokaryotes but few have been documented in eukaryotes. The natural 2µ plasmid present in budding yeast Saccharomyces cerevisiae is one of the most well characterized. This highly stable genetic element coexists with its host for millions of years, efficiently segregating at each cell division through a mechanism that remains poorly understood. Using proximity ligation (Hi-C, MicroC) to map the contacts between the 2µ and yeast chromosomes under dozens of different biological conditions, we found that the plasmid tether preferentially on regions with low transcriptional activity, often corresponding to long inactive genes, throughout the cell cycle. Common players in chromosome structure such as members of the structural maintenance of chromosome complexes (SMC) are not involved in these contacts, and depend instead on a nucleosomal signal associated with a depletion of RNA Pol II. These contacts are highly stable, and can be established within minutes. Our data show that the plasmid segregates by binding to transcriptionally silent regions of the host chromosomes. This strategy may concern other types of DNA molecules and species beyond S. cerevisiae, as suggested by the binding pattern of the natural Ddp5 plasmid along Dictyostelium discoideum chromosomes’ silent regions
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Drechsler, Carina [Verfasser], Heiko [Akademischer Betreuer] Heerklotz et Rolf [Akademischer Betreuer] Schubert. « Phosphatidylserine asymmetric vesicles as eukaryotic plasma membrane model ». Freiburg : Universität, 2018. http://d-nb.info/1175378763/34.

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Ferrell, James R. « "Effects of nonthermal plasma on prokaryotic and eukaryotic cells" ». Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1365781078.

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Ponce, Toledo Rafael Isaac. « Origins and early evolution of photosynthetic eukaryotes ». Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS047/document.

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Les plastes primaires proviennent d'une cyanobactérie qui a établi une relationendosymbiotique avec un hôte eucaryote. Cet événement a donné naissance au super-groupeArchaeplastida qui inclut les Viridiplantae (algues vertes et plantes terrestres), les Rhodophyta (alguesrouges) et les Glaucophyta. Suite à l'endosymbiose primaire, les algues rouges et vertes ont étendu lacapacité de photosynthèse à d'autres lignées eucaryotes via des endosymbioses secondaires. Bien quedes progrès considérables aient été réalisés dans la compréhension de l'évolution des eucaryotesphotosynthétiques, d'importantes questions sont restées ouvertes, telles que l’identité de la lignéecyanobactérienne la plus proche des plastes primaires ainsi que le nombre et l'identité des partenairesdans les endosymbioses secondaires.Ma thèse a consisté à étudier l'origine et l'évolution précoce des eucaryotes photosynthétiques enutilisant des approches phylogénétiques et phylogénomiques. Je montre par mon travail que les plastesprimaires ont évolué à partir d'un symbiote phylogénétiquement proche de Gloeomargarita lithophora,une cyanobactérie représentant un clade s’étant diversifié précocement et qui a été détectéeuniquement dans les milieux terrestres. Ce résultat fournit des pistes nouvelles sur le contexteécologique dans lequel l'endosymbiose primaire a probablement eu lieu. En ce qui concerne l'évolutiondes lignées eucaryotes avec des plastes secondaires, je montre que les génomes nucléaires deschlorarachniophytes et des euglénophytes, deux lignées photosynthétiques avec des plastes dérivésd'algues vertes, encodent un grand nombre de gènes acquis par transferts depuis des algues rouges.Enfin, je mets en évidence que SELMA, la machinerie de translocation des protéines à travers laseconde membrane externe des plastes rouges secondaires à quatre membranes, a une histoireétonnamment compliquée aux implications évolutives importantes : les cryptophytes ont recruté unensemble de composants de SELMA différent de ceux des haptophytes, straménopiles et alvéolés.Ainsi, ma thèse a permis d’identifier pour la première fois la lignée cyanobactérienne la plus proche desplastes primaires et apporte de nouvelles pistes pour éclaircir les événements complexes qui ontjalonné l’évolution des eucaryotes photosynthétiques secondaires
Primary plastids derive from a cyanobacterium that entered into an endosymbioticrelationship with a eukaryotic host. This event gave rise to the supergroup Archaeplastida whichcomprises Viridiplantae (green algae and land plants), Rhodophyta (red algae) and Glaucophyta. Afterprimary endosymbiosis, red and green algae spread the ability to photosynthesize to other eukaryoticlineages via secondary endosymbioses. Although considerable progress has been made in theunderstanding of the evolution of photosynthetic eukaryotes, important questions remained debatedsuch as the present-day closest cyanobacterial lineage to primary plastids as well as the number andidentity of partners in secondary endosymbioses.The main objectives of my PhD were to study the origin and evolution of plastid-bearing eukaryotesusing phylogenetic and phylogenomic approaches to shed some light on how primary and secondaryendosymbioses occurred. In this work, I show that primary plastids evolved from a close relative ofGloeomargarita lithophora, a recently sequenced early-branching cyanobacterium that has been onlydetected in terrestrial environments. This result provide interesting hints on the ecological setting whereprimary endosymbiosis likely took place. Regarding the evolution of eukaryotic lineages with secondaryplastids, I show that the nuclear genomes of chlorarachniophytes and euglenids, two photosyntheticlineages with green alga-derived plastids, encode for a large number of genes acquired by transfersfrom red algae. Finally, I highlight that SELMA, the translocation machinery putatively used to importproteins across the second outermost membrane of secondary red plastids with four membranes, has asurprisingly complex history with strong evolutionary implications: cryptophytes have recruited a set ofSELMA components different from those present in haptophytes, stramenopiles and alveolates.In conclusion, during my PhD I identified for the first time the closest living cyanobacterium to primaryplastids and provided new insights on the complex evolution that have undergone secondary plastid-bearing eukaryotes
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Wisecaver, Jennifer Hughes. « Horizontal Gene Transfer and Plastid Endosymbiosis in Dinoflagellate Gene Innovation ». Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265594.

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Recent studies suggest that horizontal gene transfer (HGT) plays an important role in niche adaptation in some eukaryotes and may be a major evolutionary force in unicellular lineages. One subcategory of HGT is endosymbiotic gene transfer (EGT), which is characterized by a large influx of genes from endosymbiont to host nuclear genome and is a critical step in the establishment of permanent organelles, such as plastids. The dinoflagellates are a diverse group of mostly marine eukaryotes that have a propensity for both HGT and plastid endosymbiosis. Many dinoflagellates are predators and can acquire both genes and plastids from prey, blurring the distinction between HGT and EGT. Here, I measure genome mosaicism in dinoflagellates to investigate how HGT has impacted gene innovation and plastid endosymbiosis in this group. Because analysis of HGT depends on accurate phylogenetic trees, I first assessed the sensitivity of automated phylogenomic methods to variation in taxon sampling due to homolog selection parameters. Using methods based on this analysis, I showed that a large amount of HGT has occurred in dinoflagellates, particularly from bacterial donors. Further, I demonstrated that the dinoflagellate Alexandrium tamarense has the largest number of genes gained relative to related eukaryotes using ancestral gene content reconstruction. Additionally, dinoflagellates have lost several ubiquitous eukaryotic metabolic genes, but missing genes have been functionally replaced by xenologs from many evolutionarysources. Other transferred genes are involved in diverse functions. These results suggest that dinoflagellate genomes are heavily impacted by HGT. Also, I investigated the timing and consequences of HGT in plastid endosymbiosis. Using the dinflagellate Dinophysis acuminata, a mixotrophic species that sequesters and maintains prey plastids, I identified plastid-targeted proteins that function in photosystem stabilization and metabolite transport. Dinophysis acuminate may be able to extend the useful life of the stolen plastid by protecting the photosystem and replacing damaged transporters. Phylogenetic analyses showed that genes are derived from multiple sources indicating a complex evolutionary history involving HGT. Dinophysis acuminate can acquire both genes and plastids from prey, which suggests that HGT could play an important role in plastid acquisition during the earliest stages of this transition.
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Jerbi, Chaabnia Soumaya. « Rôle du facteur de terminaison de la traduction eRF3 (eukaryotic Release Factor 3) dans la stabilité des ARN messagers ». Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066391/document.

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La désadénylation des ARNm fait intervenir les complexes de désadénylation PAN2-PAN3 et CCR4-NOT-TOB mais aussi le complexe de terminaison de la traduction eRF1-eRF3. Ces trois complexes ont la capacité d'interagir avec la protéine PABP. Cependant, le rôle d'eRF3 n'est pas clairement établi. Il a été décrit que les facteurs eRF3, PAN3 et TOB sont en compétition pour l'interaction avec PABP et qu'il y a un couplage entre la terminaison de la traduction et la désadénylation assuré par eRF3. Chez l'homme, le gène eRF3/GSPT1 présente 5 formes alléliques qui diffèrent par le nombre de répétitions de codons GGC à l'extrémité 5' du cadre de lecture (7, 9, 10, 11 et 12-GGC). Une corrélation entre l'allèle 12-GGC et le risque de développement de cancer du sein et de l'estomac a été mis en évidence. Notre objectif est (i) d'améliorer notre compréhension du rôle d'eRF3 dans le processus de couplage traduction-dégradation des ARNm, (ii) de comprendre l'effet du polymorphisme de la région N-terminale d'eRF3 sur son interaction avec PABP. A travers la méthode de résonnance plasmonique de surface (SPR), nous montrons que l'affinité de la forme allélique 12-GGC est 10 fois plus faible que celle d'eRF3a (10-GGC). Cette différence est essentiellement due à la plus faible association de la forme 12-GGC avec PABP. La plus faible affinité de la forme 12-GGC d'eRF3 entrainerait une dérégulation de la désadénylation au moins pour certains ARNm et pourrait ainsi promouvoir la prolifération cellulaire et la carcinogenèse. La région N-terminale d'eRF3 contenant la répétition de glycine joue un rôle crucial dans l'interaction eRF3-PABP, dans la désadénylation et donc dans la stabilité de l'ARNm
The mRNA deadenylation involves the deadenylation complexes PAN2-PAN3 and CCR4-NOT-TOB and the translation termination complex eRF1-eRF3. All three proteins, eRF3, PAN3 and TOB, interact with the PABP protein. However, the role of eRF3 is still unclear. It has been reported that eRF3, TOB and PAN3 compete for the binding to PABP. Recently, it has been suggested that eRF3 may regulate mRNA deadenylation in a translation termination-coupled manner. In human, the gene eRF3/GSPT1, contains a trinucleotide GGC repeat in its 5’ end which lead to 5 allelic forms of the gene. There are five known alleles of this gene (7, 9, 10, 11 and 12-GGC). A strong correlation between the longest allele (12-GGC) and gastric and breast cancer development has been reported. Our project was (i) to improve our understanding on the role of eRF3 in the coupling of mRNA deadenylation with translation termination, (ii) to understand whether the GGC repeat polymorphism of eRF3 influences eRF3-PABP interaction. The kinetic measurements of eRF3-PABP interaction obtained by Surface Plasmon Resonance (SPR) show that the affinity of the allelic 12-GGC form is 10 fold lower than that of eRF3a (10-GGC). This decrease is mostly due to difference in the association rate of the complex. The weaker affinity of the 12-GGC allelic form may result in a deregulation of deadenylation, at least for some mRNAs, and thus, could promote cell proliferation and carcinogenesis. In fine, we show that the N-terminal region of eRF3 containing the glycine expansion plays a key role in the eRF3-PABP interaction, in the deadenylation process, and hence, in mRNA stability
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Jerbi, Chaabnia Soumaya. « Rôle du facteur de terminaison de la traduction eRF3 (eukaryotic Release Factor 3) dans la stabilité des ARN messagers ». Electronic Thesis or Diss., Paris 6, 2015. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2015PA066391.pdf.

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La désadénylation des ARNm fait intervenir les complexes de désadénylation PAN2-PAN3 et CCR4-NOT-TOB mais aussi le complexe de terminaison de la traduction eRF1-eRF3. Ces trois complexes ont la capacité d'interagir avec la protéine PABP. Cependant, le rôle d'eRF3 n'est pas clairement établi. Il a été décrit que les facteurs eRF3, PAN3 et TOB sont en compétition pour l'interaction avec PABP et qu'il y a un couplage entre la terminaison de la traduction et la désadénylation assuré par eRF3. Chez l'homme, le gène eRF3/GSPT1 présente 5 formes alléliques qui diffèrent par le nombre de répétitions de codons GGC à l'extrémité 5' du cadre de lecture (7, 9, 10, 11 et 12-GGC). Une corrélation entre l'allèle 12-GGC et le risque de développement de cancer du sein et de l'estomac a été mis en évidence. Notre objectif est (i) d'améliorer notre compréhension du rôle d'eRF3 dans le processus de couplage traduction-dégradation des ARNm, (ii) de comprendre l'effet du polymorphisme de la région N-terminale d'eRF3 sur son interaction avec PABP. A travers la méthode de résonnance plasmonique de surface (SPR), nous montrons que l'affinité de la forme allélique 12-GGC est 10 fois plus faible que celle d'eRF3a (10-GGC). Cette différence est essentiellement due à la plus faible association de la forme 12-GGC avec PABP. La plus faible affinité de la forme 12-GGC d'eRF3 entrainerait une dérégulation de la désadénylation au moins pour certains ARNm et pourrait ainsi promouvoir la prolifération cellulaire et la carcinogenèse. La région N-terminale d'eRF3 contenant la répétition de glycine joue un rôle crucial dans l'interaction eRF3-PABP, dans la désadénylation et donc dans la stabilité de l'ARNm
The mRNA deadenylation involves the deadenylation complexes PAN2-PAN3 and CCR4-NOT-TOB and the translation termination complex eRF1-eRF3. All three proteins, eRF3, PAN3 and TOB, interact with the PABP protein. However, the role of eRF3 is still unclear. It has been reported that eRF3, TOB and PAN3 compete for the binding to PABP. Recently, it has been suggested that eRF3 may regulate mRNA deadenylation in a translation termination-coupled manner. In human, the gene eRF3/GSPT1, contains a trinucleotide GGC repeat in its 5’ end which lead to 5 allelic forms of the gene. There are five known alleles of this gene (7, 9, 10, 11 and 12-GGC). A strong correlation between the longest allele (12-GGC) and gastric and breast cancer development has been reported. Our project was (i) to improve our understanding on the role of eRF3 in the coupling of mRNA deadenylation with translation termination, (ii) to understand whether the GGC repeat polymorphism of eRF3 influences eRF3-PABP interaction. The kinetic measurements of eRF3-PABP interaction obtained by Surface Plasmon Resonance (SPR) show that the affinity of the allelic 12-GGC form is 10 fold lower than that of eRF3a (10-GGC). This decrease is mostly due to difference in the association rate of the complex. The weaker affinity of the 12-GGC allelic form may result in a deregulation of deadenylation, at least for some mRNAs, and thus, could promote cell proliferation and carcinogenesis. In fine, we show that the N-terminal region of eRF3 containing the glycine expansion plays a key role in the eRF3-PABP interaction, in the deadenylation process, and hence, in mRNA stability
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Livres sur le sujet "Eukaryotic plasmid"

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Esser, Karl, Ulrich Kück, Christine Lang-Hinrichs, Paul Lemke, Heinz Dieter Osiewacz, Ulf Stahl et Paul Tudzynski. Plasmids of Eukaryotes. Berlin, Heidelberg : Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82585-9.

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1924-, Esser Karl, dir. Plasmids of eukaryotes : Fundamentals and applications. Berlin : Springer-Verlag, 1986.

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Plasmids of Eukaryotes. Springer Verlag, 1986.

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Lang-Hinrichs, Christine, Paul Lemke, Ulrich Kück, Heinz D. Osiewacz et Karl Esser. Plasmids of Eukaryotes : Fundamentals and Applications. Springer London, Limited, 2012.

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Essek, K. Plasmids of Eukaryotes : Fundamentals and Applications (Heidelberg Science Library). Springer, 1986.

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Wickner, Reed. Extrachromosomal Elements in Lower Eukaryotes. Springer London, Limited, 2012.

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Wickner, Reed. Extrachromosomal Elements in Lower Eukaryotes. Springer, 2012.

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Extrachromosomal elements in lower eukaryotes. New York : Plenum Press, 1986.

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Chapitres de livres sur le sujet "Eukaryotic plasmid"

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Bandele, Omari J., et Neil Osheroff. « Cleavage of Plasmid DNA by Eukaryotic Topoisomerase II ». Dans Methods in Molecular Biology, 39–47. Totowa, NJ : Humana Press, 2009. http://dx.doi.org/10.1007/978-1-60761-340-4_4.

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Mäkelä, P. Helena, Pertti Koski, Petri Riikonen, Suvi Taira, Harry Holthöfer et Mikael Rhen. « The Virulence Plasmid of Salmonella Encodes a Protein Resembling Eukaryotic Tropomyosins ». Dans Biology of Salmonella, 115–20. Boston, MA : Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-2854-8_14.

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Hanak, Julian A. J., et Rocky M. Cranenburgh. « Antibiotic-Free Plasmid Selection and Maintenance in Bacteria ». Dans Recombinant Protein Production with Prokaryotic and Eukaryotic Cells. A Comparative View on Host Physiology, 111–24. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-015-9749-4_9.

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Boudrant, Joseph, Baolinh Le, Frantz Fournier et Christian Fonteix. « Modelling of Segregational Plasmid Instability of Recombinant Strain Suspension of Escherichia coli ». Dans Recombinant Protein Production with Prokaryotic and Eukaryotic Cells. A Comparative View on Host Physiology, 125–39. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-015-9749-4_10.

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Douce, Roland, Claude Alban, Maryse A. Block et Jacques Joyard. « The Plastid Envelope Membranes : Purification, Composition and Role in Plastid Biogenesis ». Dans Organelles in Eukaryotic Cells, 157–76. Boston, MA : Springer US, 1989. http://dx.doi.org/10.1007/978-1-4613-0545-3_11.

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Hackstein, J. H. P., H. Schubert, J. Rosenberg, U. Mackenstedt, M. van den Berg, S. Brul, J. Derksen et H. C. P. Matthijs. « Plastid-Like Organelles in Anaerobic Mastigotes and Parasitic Apicomplexans ». Dans Eukaryotism and Symbiosis, 49–56. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60885-8_4.

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Garber, Robert C., J. J. Lin et O. C. Yoder. « Mitochondrial Plasmids in Cochliobolus Heterostrophus ». Dans Extrachromosomal Elements in Lower Eukaryotes, 105–18. Boston, MA : Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5251-8_9.

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Hess, W. R., B. Linke et T. Börner. « Impact of Plastid Differentiation on Transcription of Nuclear and Mitochondrial Genes ». Dans Eukaryotism and Symbiosis, 233–42. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60885-8_18.

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McFadden, G. I., et P. Gilson. « What’s Eating Eu ? The Role of Eukaryote/Eukaryote Endosymbioses in Plastid Origins ». Dans Eukaryotism and Symbiosis, 24–39. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60885-8_2.

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Volkert, Fredric C., Ling-Chuan Chen Wu, Paul A. Fisher et James R. Broach. « Survival Strategies of the Yeast Plasmid Two-Micron Circle ». Dans Extrachromosomal Elements in Lower Eukaryotes, 375–96. Boston, MA : Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5251-8_29.

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Actes de conférences sur le sujet "Eukaryotic plasmid"

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Homes, W. E., H. R. Lijnen, L. Nelles, C. Kluft et D. Collen. « AN ALANINE INSERTION IN α2-ANTIPLASMIN ‘ENSCHEDE’ ABOLISHES ITS PLASM IN INHIBITORY ACTIVITY ». Dans XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642897.

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Congenital deficiencies of the fibrinolytic inhibitor α2antiplasmin (α2AP) may result in bleeding disorders. An abnormal a AP (α2AP‘Enschede’) is known. 2 siblings with 3% functional activity and normal antigen level have parents with 50% activity and normal antigen. The protein interacts normally with the lysine-binding site(s) of plasmin(ogen) but does not inhibit plasmin irreversibly. α2AP Enschede is a plasmin substrate that like the normal protein releases a M 8,000 peptide upon reaction with plasmin. In the present study, Southern blot analysis, using an α2AP cDNA probe showed a restriction fragment length polymorphism within a small genomic DNA fragment of the Enschede family members. Cloning and sequencing of these fragments revealed a GCG inframe insertion that results in an alanine addition between amino acids 353 and 357, 7-10 positions NH -terminal to the reactive site PI residue, Arg364. This area is homologous to the A4 B-sheet of reactive site cleaved a -antitrypsin. Clones from each individual confirm the parents as true heterozygotes and the children as true homozygotes. A cloned genomic DNA sequence containing the insertion (V ) was exchanged for the normal sequence in a eukaryotic a AP expression plasmid. Recombinant α2AP‘Enschede’ (ra AfVAla) purified from the conditioned media of transfected Chinese Hamster Ovary Cells is analogous to plasma a α2AP‘Enschede’ with respect to interactions with plasmin and plasminogen. Preliminary analysis of the released Mr 8,000 recombinant peptide shows that its NH -terminus is the same as the peptide cleaved from normal a AP. Although ra α2APVAla does not inhibit plasmin irreversibly it does, however, act as a competitive inhibitor of hydrolysis of the chromogenic substrate S-2251 by plasmin.The K for this interaction is 25 nM. Thus, α2APAla retains a high affinity for the active center of plasmin. In conclusion, an Ala insertion near the reactive site of α2AP must have resulted in a structural perturbation that has abolished the plasmin inhibitory activity of a α2AP‘Enschede’. This variant may provide a model for further investigation of structure-function relationships in the serpins which determine the relative inhibitor vs. substrate properties.
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Tang, Y. Z., X. Lu, F. Dobbs et M. Laroussi. « Effects of Cold Air Plasma on Eukaryotic Microalgae ». Dans 2007 IEEE Pulsed Power Plasma Science Conference. IEEE, 2007. http://dx.doi.org/10.1109/ppps.2007.4345638.

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Zadorozhny, A. M., S. V. Sharabrin, A. P. Rudometov et L. I. Karpenko. « CONSTRUCTION OF A DNA TEMPLATE FOR THE PRODUCTION OF MRNA ENCODING RBD OF THE S PROTEIN OF THE SARS-COV-2 OMICRON BA.2 VIRUS ». Dans X Международная конференция молодых ученых : биоинформатиков, биотехнологов, биофизиков, вирусологов и молекулярных биологов — 2023. Novosibirsk State University, 2023. http://dx.doi.org/10.25205/978-5-4437-1526-1-77.

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The work is devoted to the construction of DNA templates for in vitro production of mRNAs encoding the receptor-binding domain (RBD) of the S protein of the SARS-CoV-2 virus, the genetic variant Omicron BA.2. Three plasmids DNA templates were obtained that encode the RBD protein gene, but differ in that they carry different 5’UTRs and 3’UTRs. A variant of the DNA template was chosen, which provides the synthesis of mRNA-RBD most effectively expressed in eukaryotic cells.
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Pannekok, H., A. J. Van Zonneveid, C. J. M. de vries, M. E. MacDonald, H. Veerman et F. Blasi. « FUNCTIONAL PROPERTIES OF DELETION-MUTANTS OF TISSUE-TYPE PLASMINOGEN ACTIVATOR ». Dans XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643724.

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Over the past twenty-five years, genetic methods have generated a wealth of information on the regulation and the structure-function relationship of bacterial genes.These methods are based on the introduction of random mutations in a gene to alter its function. Subsequently, genetic techniques cure applied to localize the mutation, while the nature of the impairedfunction could be determined using biochemical methods. Classic examples of this approach is now considered to be the elucidation of the structure and function of genes, constituting the Escherichia coli lactose (lac) and tryptophan (trp) operons,and the detailed establishment of the structure and function of the repressor (lacl) of the lac operon. Recombinant DNA techniques and the development of appropriate expression systems have provided the means both to study structure and functionof eukaryotic (glyco-) proteins and to create defined mutations with a predestinedposition. The rationale for the construction of mutant genes should preferentiallyrely on detailed knowledge of the three-dimensional structure of the gene product.Elegant examples are the application of in vitro mutagenesis techniques to substitute amino-acid residues near the catalytic centre of subtilisin, a serine proteasefrom Bacillus species and to substituteanamino acid in the reactive site (i.e. Pi residue; methionine) of α-antitrypsin, a serine protease inhibitor. Such substitutions have resulted into mutant proteins which are less susceptible to oxidation and, in some cases, into mutant proteins with a higher specific activity than the wild-type protein.If no data are available on the ternary structure of a protein, other strategies have to be developed to construct intelligent mutants to study the relation between the structure and the function of a eukaryotic protein. At least for a number of gene families, the gene structure is thought to be created by "exon shuffling", an evolutionary recombinational process to insert an exon or a set of exons which specify an additional structural and/or functional domain into a pre-existing gene. Both the structure of the tissue-type plasminogen activator protein(t-PA) and the t-PA gene suggest that this gene has evolved as a result of exon shuffling. As put forward by Gilbert (Science 228 (1985) 823), the "acid test"to prove the validity of the exon shuffling theory is either to delete, insert or to substitute exon(s) (i.e. in the corresponding cDNA) and toassay the properties of the mutant proteins to demonstrate that an exon or a set of adjacent exons encode (s) an autonomousfunction. Indeed, by the construction of specific deletions in full-length t-PA cDNA and expression of mutant proteins intissue-culture cells, we have shown by this approach that exon 2 of thet-PA gene encodes the function required forsecretion, exon 4 encodes the "finger" domain involved in fibrin binding(presumably on undegraded fibrin) and the set of exons 8 and 9 specifies kringle 2, containing a lysine-binding sit(LBS) which interacts with carboxy-terminal lysines, generated in fibrin after plasmic digestion. Exons 10 through 14 encode the carboxy-ter-minal light chain of t-PA and harbor the catalytic centre of the molecule and represents the predominant "target site" for the fast-acting endothelial plasminogen activator inhibitor (PAI-1).As a follow-up of this genetic approach to construct deletion mutants of t-PA, we also created substitution mutants of t-PA. Different mutants were constructed to substitute cDNA encoding thelight chain of t-PA by cDNA encoding the B-chain of urokinase (u-PA), in order to demonstrate that autonomous structural and functional domains of eitherone of the separate molecules are able toexert their intrinsic properties in a different context (C.J.M. de Vries et al., this volume). The possibilities and the limitations of this approach to study the structure and the function of t-PA and of other components of the fibrinolytic process will be outlined.
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Rapports d'organisations sur le sujet "Eukaryotic plasmid"

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Tzfira, Tzvi, Michael Elbaum et Sharon Wolf. DNA transfer by Agrobacterium : a cooperative interaction of ssDNA, virulence proteins, and plant host factors. United States Department of Agriculture, décembre 2005. http://dx.doi.org/10.32747/2005.7695881.bard.

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Agrobacteriumtumefaciensmediates genetic transformation of plants. The possibility of exchanging the natural genes for other DNA has led to Agrobacterium’s emergence as the primary vector for genetic modification of plants. The similarity among eukaryotic mechanisms of nuclear import also suggests use of its active elements as media for non-viral genetic therapy in animals. These considerations motivate the present study of the process that carries DNA of bacterial origin into the host nucleus. The infective pathway of Agrobacterium involves excision of a single-stranded DNA molecule (T-strand) from the bacterial tumor-inducing plasmid. This transferred DNA (T-DNA) travels to the host cell cytoplasm along with two virulence proteins, VirD2 and VirE2, through a specific bacteriumplant channel(s). Little is known about the precise structure and composition of the resulting complex within the host cell and even less is known about the mechanism of its nuclear import and integration into the host cell genome. In the present proposal we combined the expertise of the US and Israeli labs and revealed many of the biophysical and biological properties of the genetic transformation process, thus enhancing our understanding of the processes leading to nuclear import and integration of the Agrobacterium T-DNA. Specifically, we sought to: I. Elucidate the interaction of the T-strand with its chaperones. II. Analyzing the three-dimensional structure of the T-complex and its chaperones in vitro. III. Analyze kinetics of T-complex formation and T-complex nuclear import. During the past three years we accomplished our goals and made the following major discoveries: (1) Resolved the VirE2-ssDNA three-dimensional structure. (2) Characterized VirE2-ssDNA assembly and aggregation, along with regulation by VirE1. (3) Studied VirE2-ssDNA nuclear import by electron tomography. (4) Showed that T-DNA integrates via double-stranded (ds) intermediates. (5) Identified that Arabidopsis Ku80 interacts with dsT-DNA intermediates and is essential for T-DNA integration. (6) Found a role of targeted proteolysis in T-DNA uncoating. Our research provide significant physical, molecular, and structural insights into the Tcomplex structure and composition, the effect of host receptors on its nuclear import, the mechanism of T-DNA nuclear import, proteolysis and integration in host cells. Understanding the mechanical and molecular basis for T-DNA nuclear import and integration is an essential key for the development of new strategies for genetic transformation of recalcitrant plant species. Thus, the knowledge gained in this study can potentially be applied to enhance the transformation process by interfering with key steps of the transformation process (i.e. nuclear import, proteolysis and integration). Finally, in addition to the study of Agrobacterium-host interaction, our research also revealed some fundamental insights into basic cellular mechanisms of nuclear import, targeted proteolysis, protein-DNA interactions and DNA repair.
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Elbaum, Michael, et Peter J. Christie. Type IV Secretion System of Agrobacterium tumefaciens : Components and Structures. United States Department of Agriculture, mars 2013. http://dx.doi.org/10.32747/2013.7699848.bard.

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Objectives: The overall goal of the project was to build an ultrastructural model of the Agrobacterium tumefaciens type IV secretion system (T4SS) based on electron microscopy, genetics, and immunolocalization of its components. There were four original aims: Aim 1: Define the contributions of contact-dependent and -independent plant signals to formation of novel morphological changes at the A. tumefaciens polar membrane. Aim 2: Genetic basis for morphological changes at the A. tumefaciens polar membrane. Aim 3: Immuno-localization of VirB proteins Aim 4: Structural definition of the substrate translocation route. There were no major revisions to the aims, and the work focused on the above questions. Background: Agrobacterium presents a unique example of inter-kingdom gene transfer. The process involves cell to cell transfer of both protein and DNA substrates via a contact-dependent mechanism akin to bacterial conjugation. Transfer is mediated by a T4SS. Intensive study of the Agrobacterium T4SS has made it an archetypal model for the genetics and biochemistry. The channel is assembled from eleven protein components encoded on the B operon in the virulence region of the tumor-inducing plasmid, plus an additional coupling protein, VirD4. During the course of our project two structural studies were published presenting X-ray crystallography and three-dimensional reconstruction from electron microscopy of a core complex of the channel assembled in vitro from homologous proteins of E. coli, representing VirB7, VirB9, and VirB10. Another study was published claiming that the secretion channels in Agrobacterium appear on helical arrays around the membrane perimeter and along the entire length of the bacterium. Helical arrangements in bacterial membranes have since fallen from favor however, and that finding was partially retracted in a second publication. Overall, the localization of the T4SS within the bacterial membranes remains enigmatic in the literature, and we believe that our results from this project make a significant advance. Summary of achievements : We found that polar inflations and other membrane disturbances relate to the activation conditions rather than to virulence protein expression. Activation requires low pH and nutrient-poor medium. These stress conditions are also reflected in DNA condensation to varying degrees. Nonetheless, they must be considered in modeling the T4SS as they represent the relevant conditions for its expression and activity. We identified the T4SS core component VirB7 at native expression levels using state of the art super-resolution light microscopy. This marker of the secretion system was found almost exclusively at the cell poles, and typically one pole. Immuno-electron microscopy identified the protein at the inner membrane, rather than at bridges across the inner and outer membranes. This suggests a rare or transient assembly of the secretion-competent channel, or alternatively a two-step secretion involving an intermediate step in the periplasmic space. We followed the expression of the major secreted effector, VirE2. This is a single-stranded DNA binding protein that forms a capsid around the transferred oligonucleotide, adapting the bacterial conjugation to the eukaryotic host. We found that over-expressed VirE2 forms filamentous complexes in the bacterial cytoplasm that could be observed both by conventional fluorescence microscopy and by correlative electron cryo-tomography. Using a non-retentive mutant we observed secretion of VirE2 from bacterial poles. We labeled the secreted substrates in vivo in order detect their secretion and appearance in the plant cells. However the low transfer efficiency and significant background signal have so far hampered this approach.
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Schuster, Gadi, et David Stern. Integration of phosphorus and chloroplast mRNA metabolism through regulated ribonucleases. United States Department of Agriculture, août 2008. http://dx.doi.org/10.32747/2008.7695859.bard.

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New potential for engineering chloroplasts to express novel traits has stimulated research into relevant techniques and genetic processes, including plastid transformation and gene regulation. This proposal continued our long time BARD-funded collaboration research into mechanisms that influence chloroplast RNA accumulation, and thus gene expression. Previous work on cpRNA catabolism has elucidated a pathway initiated by endonucleolytic cleavage, followed by polyadenylation and exonucleolytic degradation. A major player in this process is the nucleus-encoded exoribonuclease/polymerasepolynucleotidephoshorylase (PNPase). Biochemical characterization of PNPase has revealed a modular structure that controls its RNA synthesis and degradation activities, which in turn are responsive to the phosphate (P) concentration. However, the in vivo roles and regulation of these opposing activities are poorly understood. The objectives of this project were to define how PNPase is controlled by P and nucleotides, using in vitro assays; To make use of both null and site-directed mutations in the PNPgene to study why PNPase appears to be required for photosynthesis; and to analyze plants defective in P sensing for effects on chloroplast gene expression, to address one aspect of how adaptation is integrated throughout the organism. Our new data show that P deprivation reduces cpRNA decay rates in vivo in a PNPasedependent manner, suggesting that PNPase is part of an organismal P limitation response chain that includes the chloroplast. As an essential component of macromolecules, P availability often limits plant growth, and particularly impacts photosynthesis. Although plants have evolved sophisticated scavenging mechanisms these have yet to be exploited, hence P is the most important fertilizer input for crop plants. cpRNA metabolism was found to be regulated by P concentrations through a global sensing pathway in which PNPase is a central player. In addition several additional discoveries were revealed during the course of this research program. The human mitochondria PNPase was explored and a possible role in maintaining mitochondria homeostasis was outlined. As polyadenylation was found to be a common mechanism that is present in almost all organisms, the few examples of organisms that metabolize RNA with no polyadenylation were analyzed and described. Our experiment shaded new insights into how nutrient stress signals affect yield by influencing photosynthesis and other chloroplast processes, suggesting strategies for improving agriculturally-important plants or plants with novel introduced traits. Our studies illuminated the poorly understood linkage of chloroplast gene expression to environmental influences other than light quality and quantity. Finely, our finding significantly advanced the knowledge about polyadenylation of RNA, the evolution of this process and its function in different organisms including bacteria, archaea, chloroplasts, mitochondria and the eukaryotic cell. These new insights into chloroplast gene regulation will ultimately support plant improvement for agriculture
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