44 research outputs found
An essential role for Clp1 in assembly of polyadenylation complex CF IA and Pol II transcription termination
Polyadenylation is a co-transcriptional process that modifies mRNA 3âČ-ends in eukaryotes. In yeast, CF IA and CPF constitute the core 3âČ-end maturation complex. CF IA comprises Rna14p, Rna15p, Pcf11p and Clp1p. CF IA interacts with the C-terminal domain of RNA Pol II largest subunit via Pcf11p which links pre-mRNA 3âČ-end processing to transcription termination. Here, we analysed the role of Clp1p in 3âČ processing. Clp1p binds ATP and interacts in CF IA with Pcf11p only. Depletion of Clp1p abolishes transcription termination. Moreover, we found that association of mutations in the ATP-binding domain and in the distant Pcf11p-binding region impair 3âČ-end processing. Strikingly, these mutations prevent not only Clp1p-Pcf11p interaction but also association of Pcf11p with Rna14p-Rna15p. ChIP experiments showed that Rna15p cross-linking to the 3âČ-end of a protein-coding gene is perturbed by these mutations whereas Pcf11p is only partially affected. Our study reveals an essential role of Clp1p in CF IA organization. We postulate that Clp1p transmits conformational changes to RNA Pol II through Pcf11p to couple transcription termination and 3âČ-end processing. These rearrangements likely rely on the correct orientation of ATP within Clp1p
Formules dâadresse et antonomases du nom commun : deux opĂ©ratrices du rituel dans les discours de meeting pour lâĂ©lection prĂ©sidentielle française
Ă partir dâun rappel anthropologique sur le rituel, cet article Ă©tudie deux opĂ©ratrices particuliĂšres du rituel au sein dâun corpus constituĂ© de discours de meeting tenus par des candidats et candidates aux Ă©lections prĂ©sidentielles françaises de 2002, 2007 et 2012 : les « formules dâadresse » et les antonomases du nom commun, formellement repĂ©rĂ©es par une exploration lexicomĂ©trique. Lâexamen des formules dâadresse tĂ©moigne dâune reprĂ©sentation situĂ©e du social. Elles sont de ce fait remarÂŹquaÂŹbleÂŹment stables pour un locuteur ou une locutrice donnĂ©-e. De la mĂȘme maniĂšre, lâanalyse de sept antonomases du nom commun rĂ©vĂšle les prĂ©fĂ©rences de chaque locuteur ou locutrice en termes de transcendance politique mobilisĂ©e en discours. Ces constats permettent de mettre en Ă©vidence que si le rituel se matĂ©rialise en discours par la prĂ©sence dâun certain nombre de traits pragmatiques et Ă©nonciatifs formels, il y a en rĂ©alitĂ© autant de maniĂšres de rĂ©aliser le rituel quâil y a dâ« ordonÂŹnateurs ou ordonnatrices » politiques. Ce faisant, le rituel en discours de meeting Ă©lectoral se prĂ©sente avant tout comme une matĂ©rialisation discursive plastique.From an anthropological background of the ritual, this article examines two particular operators of the ritual in a corpus compound by electoral speeches held by candidates hired for the french presidential elections of 2002, 2007 and 2012: « addresseâs words » and antonomasias of common name, formally identified by lexicometric exploration. Examination of the adresseâs words reflects a set representation of the social order, and are therefore remarkably stable for a given speaker. Similarly, analysis of seven antonomasias of common name reveals the preferences of each speaker in terms of political transcendence mobilized in each speech. Based on these observations, it is thus demonstrated that if the ritual is materialized in speeches by the presence of a number of formal and pragmatic enunciative patterns, there are many ways to perform the ritual. In doing so, the ritual on speeches for french presidential elections could be consider as a discursive plastic material
Le discours de meeting Ă©lectoral : rituel d'affrontement, mĂ©diatisations, communication politique.Analyse du discours de meeting Ă©lectoral pour lâĂ©lectionprĂ©sidentielle française (2002, 2007, 2012)
This research focuses on a set of symbolic (ritual, progressive endorsement of the presidential role, transcendences mobilized, scenic imperatives), and sociopolitical pressures (individual paths, role of supporters, transformations of the audiences, interaction with other competitors, medias transformations), facing the rally speeches for the french presidential election. "Le changement câest maintenant," "Ensemble, tout devient possible ", "Prenez le pouvoir": as the campaign for the presidential election has put in his heart that fundamental promise of "transformation of the reality", which could let presuppose freedom utterance of speakers, we show that the election rally speech is strongly constrained and determined. Thus, each candidate had to comply with an expected tacit discourse, while responding to messages renewal imperatives, inherent to any process of political legitimation through discourses. Here is summarized in a few lines the vocation of this study, based on the lexicometric exploration conducted with textual data analysis software Lexico 3 and argumentative, pragmatic, enunciative and timely narrative questionning of ninety-six election rally speeches, made during campaign periods called "official" by candidates to the presidential elections of 2002, 2007, 2012 in France.Cette recherche porte sur un ensemble de dĂ©terminismes et contraintes dâordre symbolique (rituel, endossement progressif du rĂŽle prĂ©sidentiel, transcendances mobilisables, impĂ©ratifs scĂ©nographiques) et sociopolitique (trajectoires individuelles, rĂŽle des appareils partisans, Ă©volution des publics, interaction avec les autres compĂ©titeurs et compĂ©titrices, transformation des mĂ©dias) qui pĂšsent sur le discours de meeting pour lâĂ©lection prĂ©sidentielle française. « Le changement câest maintenant », « Ensemble, tout devient possible », « Prenez le pouvoir » : alors que la campagne pour lâĂ©lection prĂ©sidentielle vient placer en son coeur cette promesse fondamentale de « transformation du rĂ©el », ce qui pourrait laisser croire en une grande libertĂ© Ă©nonciative des locuteurs et des locutrices, nous montrons ici quâĂ lâinverse le discours de meeting Ă©lectoral se trouve extraordinairement contraint et dĂ©terminĂ©, que chaque candidat ou candidate doit se conformer Ă un faisceau dâattendus discursifs tacites, tout en rĂ©pondant aux impĂ©ratifs de renouvellement de messages inhĂ©rent Ă tout processus de lĂ©gitimation politique par le discours.Voici rĂ©sumĂ©e en quelques lignes la vocation de ce travail, fondĂ© sur lâexploration lexicomĂ©trique menĂ©e avec le logiciel dâanalyse de donnĂ©es textuelles Lexico 3, puis lâinterrogation argumentative, pragmatico-Ă©nonciative et ponctuellement narrative dâunThĂšse prĂ©parĂ©e au CEDITEC, (Centre d'Ătude des Discours, Images, Textes Ăcrits, Communication) UniversitĂ© Paris-Est CrĂ©teil Val-de-Marne (UPEC) Centre Pyramide â Bureau 405 80, avenue du GĂ©nĂ©ral de Gaulle 94000 CrĂ©teil Cedexcorpus composĂ© de quatre-vingt-seize discours de meeting Ă©lectoral, tenus lors de pĂ©riodes de campagne dites « officielles », par les candidates et les candidats en lice pour les Ă©lections prĂ©sidentielles de 2002, 2007, 2012 en France
The election rally speech : confrontation ritual, mediatizations, political communication election rally speech analysis for the French presidential elections (2002, 2007, 2012).
Cette recherche porte sur un ensemble de dĂ©terminismes et contraintes dâordre symbolique (rituel, endossement progressif du rĂŽle prĂ©sidentiel, transcendances mobilisables, impĂ©ratifs scĂ©nographiques) et sociopolitique (trajectoires individuelles, rĂŽle des appareils partisans, Ă©volution des publics, interaction avec les autres compĂ©titeurs et compĂ©titrices, transformation des mĂ©dias) qui pĂšsent sur le discours de meeting pour lâĂ©lection prĂ©sidentielle française. « Le changement câest maintenant », « Ensemble, tout devient possible », « Prenez le pouvoir » : alors que la campagne pour lâĂ©lection prĂ©sidentielle vient placer en son coeur cette promesse fondamentale de « transformation du rĂ©el », ce qui pourrait laisser croire en une grande libertĂ© Ă©nonciative des locuteurs et des locutrices, nous montrons ici quâĂ lâinverse le discours de meeting Ă©lectoral se trouve extraordinairement contraint et dĂ©terminĂ©, que chaque candidat ou candidate doit se conformer Ă un faisceau dâattendus discursifs tacites, tout en rĂ©pondant aux impĂ©ratifs de renouvellement de messages inhĂ©rent Ă tout processus de lĂ©gitimation politique par le discours.Voici rĂ©sumĂ©e en quelques lignes la vocation de ce travail, fondĂ© sur lâexploration lexicomĂ©trique menĂ©e avec le logiciel dâanalyse de donnĂ©es textuelles Lexico 3, puis lâinterrogation argumentative, pragmatico-Ă©nonciative et ponctuellement narrative dâunThĂšse prĂ©parĂ©e au CEDITEC, (Centre d'Ătude des Discours, Images, Textes Ăcrits, Communication) UniversitĂ© Paris-Est CrĂ©teil Val-de-Marne (UPEC) Centre Pyramide â Bureau 405 80, avenue du GĂ©nĂ©ral de Gaulle 94000 CrĂ©teil Cedexcorpus composĂ© de quatre-vingt-seize discours de meeting Ă©lectoral, tenus lors de pĂ©riodes de campagne dites « officielles », par les candidates et les candidats en lice pour les Ă©lections prĂ©sidentielles de 2002, 2007, 2012 en France.This research focuses on a set of symbolic (ritual, progressive endorsement of the presidential role, transcendences mobilized, scenic imperatives), and sociopolitical pressures (individual paths, role of supporters, transformations of the audiences, interaction with other competitors, medias transformations), facing the rally speeches for the french presidential election. "Le changement câest maintenant," "Ensemble, tout devient possible ", "Prenez le pouvoir": as the campaign for the presidential election has put in his heart that fundamental promise of "transformation of the reality", which could let presuppose freedom utterance of speakers, we show that the election rally speech is strongly constrained and determined. Thus, each candidate had to comply with an expected tacit discourse, while responding to messages renewal imperatives, inherent to any process of political legitimation through discourses. Here is summarized in a few lines the vocation of this study, based on the lexicometric exploration conducted with textual data analysis software Lexico 3 and argumentative, pragmatic, enunciative and timely narrative questionning of ninety-six election rally speeches, made during campaign periods called "official" by candidates to the presidential elections of 2002, 2007, 2012 in France
Ăducation thĂ©rapeutique du patient : incidence sur la prise en charge de la maladie parodontale en pratique quotidienne
Objectif : Ătudier lâincidence de lâĂ©ducation thĂ©rapeutique du patient (ETP) sur la prise en charge de la maladie parodontale. MĂ©thodes : Une revue systĂ©matique de la littĂ©rature a Ă©tĂ© conduite dans PUBMED et COCHRANE, visant Ă dĂ©terminer lâimpact de lâETP et de la maintenance parodontale sur lâĂ©volution de la maladie. Puis, un questionnaire anonyme a permis dâĂ©valuer si les patients Ă©taient suffisamment informĂ©s sur les moyens de prĂ©vention et les recommandations. RĂ©sultats : Sur 4566 articles, 22 ont Ă©tĂ© retenus. Neuf Ă©valuaient lâeffet dâun programme dâETP, qui semble amĂ©liorer les principaux paramĂštres cliniques (indice de plaque, indice de saignement et gingival). Treize Ă©tudes Ă©valuaient la maintenance, et soulignaient lâimportance dâune bonne observance, puisque la perte dentaire moyenne Ă©tait significativement moins importante chez les patients observants que chez les patients non compliants (-1,15 IDC 95 % [-2,18 ; -0.11], p=0,006). Le questionnaire auprĂšs de 278 patients a montrĂ© que 69 % ignoraient ce quâest une parodontite, 62 % nâont jamais bĂ©nĂ©ficiĂ© dâune sĂ©ance dĂ©diĂ©e Ă lâhygiĂšne buccodentaire, et quâenviron 50 % ne pratiquaient pas un brossage adaptĂ©. Conclusion : LâETP influence positivement lâĂ©volution de parodontopathies, mais est insuffisamment appliquĂ©e en pratique, possiblement Ă cause des contraintes de gestion du cabinet. Le dĂ©veloppement de la profession dâhygiĂ©niste dentaire ou dâapproches comme lâentretien motivationnel pourraient pallier ces limites
Maturation post-transcriptionnelle des ARN messagers chez la levure Saccharomyces cerevisiae (rÎle du facteur de clivage et polyadénylation CF IA à travers l'étude de la sous-unité Clp1p)
Chez la levure S. cerevisiae, l'ajout d'une queue poly (A) en 3' des ARNm fait intervenir les facteurs CF IA, CPF et les protéines Nab4p et Nab2p. Le facteur CF IA est composé des protéines Rna1 4p, Rna1 5p, Pcf1 1p et C1p 1p. In vitro, des extraits protéiques obtenus à partir de souches mutantes c1p1 ont une activité de maturation en 3' déficiente : C1p 1p est requise lors des deux étapes de clivage et polyadénylation. Les facteurs CF IA présents dans différents contextes ont été purifiés. Les versions mutantes de C1p 1p et la protéine Pcf1 1p ne sont pas présentes dans ces fractions. Pourtant, des expériences de double-hybride révÚlent que l'interaction entre la protéine Pcf1 1p et les formes mutantes de C1p 1p est altérée. Nos résultats suggÚrent que C1p 1p serait impliquée dans la stabilité du facteur CF IA. Par ailleurs, nous montrons que C1p 1p et Pcf1 1p sont impliquées dans la maturation en 3' des snoRNAs, une autre classe de transcrits synthétisés par l'ARN polymérase II.In yeast, mRNAs acquire a poly(A) tail at their 3'ends. This involves the factors CF IA, CPF, and the proteins Nab4p and Nab2p. CF IA is a complex comprising Rna1 4p, Rna1 5p, Pcf1 1p and C1p 1p. The latter has been found to be essential for both the cleavage and polyadenylation steps. Mutations in the CLP1 gene indeed gave rise to extracts that were unable to perform in vitro pre-mRNA 3'-end processing. Purification of CF IA in mutant backgrounds for CLP1 showed that Pcf1p and the mutant Clp 1p protein no longer copurified with CF IA. Two-hybrid analyses additionnally showed that PCF11 and mutant c1p1 alleles failed to interact at different temperatures. Finally, we investigated C1p1p and Pcf1 1p putative role in snoRNA 3' end formation. We could show that repressed expression of either CLP1 or PCF11 impaired significantly termination of transcription of snoRNA independent units, strongly suggesting their implication in 3' end formation of this other class of RNA poll II transcripts.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF
technique de compression pour les reflecteurs en utilisant loptique de transformation
National audienceDans ce papier, la conception dâun rĂ©flecteur diĂ©drique comprimĂ© via l'Optique de Transformation est abordĂ©e. La hauteur du rĂ©flecteur est rĂ©duite en utilisant un milieu homogĂšne avec une anisotropie diĂ©lectrique. La conception proposĂ©e est validĂ©e Ă f0 = 8GHz par des simulations Ă©lectromagnĂ©tiques en utilisant le logiciel COMSOL Multiphysics
Compression technique for retrodirective reflectors using transformation optics
International audienceâIn this paper, the design of compressed retrodirective reflectors via transformation optics is addressed. The proposed method enables a compressed reflector to perform as a classical retrodirective corner reflector while having a much lower profile. Using a simple linear coordinate transformation, the lower profile can be achieved with a TO domain in the reflector consisting of anisotropic homogeneous media. The proposed design is validated at f 0 =8GHz by full wave electromagnetic simulations. Furthermore, using the Effective Medium Theory approach, the practical feasibility of the involved medium distribution is discussed and verified. The results of the investigations could be of interest in different radar, communication and identification applications
Fission Yeast cdc31p Is a Component of the Half-bridge and Controls SPB Duplication
The fission yeast spindle pole body (SPB) is a nucleus-associated organelle that duplicates once each cell cycle during interphase. Duplicated SPBs serve as the poles of an intranuclear mitotic spindle after their insertion into the nuclear envelope in mitosis (Ding et al., Mol. Biol. Cell 8, 1461â1479). Here, we report the identification and characterization of Schizosaccharomyces pombe cdc31p, a member of the conserved calcium-binding centrin/CDC31 family. Immunofluorescence and immunoelectron microscopy show that cdc31p is a SPB component localized at the half-bridge structure of the SPB. cdc31 is an essential gene and Îcdc31 cells and cdc31 conditional mutant cells arrest in mitosis with a monopolar mitotic spindle organized from a single SPB. EM analysis demonstrates that mutant cdc31 cells fail to duplicate the SPB. In addition, cdc31p exhibits genetic interactions with the SPB component sad1p and is required for sad1p localization. Finally, cdc31 mutant can undergo single or multiple rounds of septation before the exit from mitosis, suggesting that cdc31p activity or SPB duplication may be required for the proper coordination between the exit from mitosis and the initiation of septation
Critical Contacts between the Eukaryotic Initiation Factor 2B (eIF2B) Catalytic Domain and both eIF2ÎČ and -2Îł Mediate Guanine Nucleotide ExchangeâżâĄ
Diverse guanine nucleotide exchange factors (GEFs) regulate the activity of GTP binding proteins. One of the most complicated pairs is eukaryotic initiation factor 2B (eIF2B) and eIF2, which function during protein synthesis initiation in eukaryotes. We have mutated conserved surface residues within the eIF2B GEF domain, located at the eIF2BÉ C terminus. Extensive genetic and biochemical characterization established how these residues contribute to GEF activity. We find that the universally conserved residue E569 is critical for activity and that even a conservative E569D substitution is lethal in vivo. Several mutations within residues close to E569 have no discernible effect on growth or GCN4 expression, but an alanine substitution at the adjacent L568 is cold sensitive and deregulates GCN4 activity at 15°C. The mutation of W699, found on a separate surface approximately 40 Ă
from E569, is also lethal. Binding studies show that W699 is critical for interaction with eIF2ÎČ, while L568 and E569 are not. In contrast, all three residues are critical for interaction with eIF2Îł. These data show that multiple contacts between eIF2Îł and eIF2BÉ mediate nucleotide exchange