Identification et caractérisation d'interacteurs d'AtMYB30, un facteur de transcription impliqué dans la régulation de la réponse hypersensible chez Arabidopsis thaliana

AtMYB30, qui appartient à la famille des facteurs de transcription de type MYB-R2R3, est un régulateur positif de la mort cellulaire hypersensible, une réponse de résistance mise en place par la plante en réponse à l'attaque par un agent pathogène. Ce travail de thèse s'est focalisé sur la recherche et la caractérisation d'interacteurs protéiques d'AtMYB30. Précédemment, dans un crible double-hybride chez la Levure, plusieurs interacteurs putatifs d'AtMYB30 avaient été identifiés : une protéine de type phospholipase A2 secrétée (AtsPLA2-a) et une protéine de type RING finger avec une fonction d'E3 ubiquitine ligase putative (MIP1). AtsPLA2-a et MIP1 interagissent physiquement avec AtMYB30 in planta et sont des régulateurs négatifs de la résistance conférée par AtMYB30. Par ailleurs, une recherche sans a priori des protéines interagissant avec AtMYB30 a été effectuée par une approche protéomique. La validation fonctionnelle des partenaires putatifs identifiés est actuellement en cours.AtMYB30, a member of the MYB-R2R3 transcription factor family, is a positive regulator of the hypersensitive cell death associated to plant response to pathogen attack. This thesis has focused on the search and characterization of AtMYB30 interacting partners. In a previous yeast two-hybrid screen, two AtMYB30 putative interacting proteins had been identified: a secretory phospholipase A2 (AtsPLA2-a) and a RING finger protein with a putative E3 ubiquitin ligase function (MIP1). AtsPLA2-a and MIP1 physically interact with AtMYB30 in planta and have been characterized as negative regulators of AtMYB30-mediated resistance responses. Finally, a proteomic approach was used to identify new AtMYB30 interacting partners. Functional validation of these AtMYB30 putative partners is in progress

New York, Paris, Strasbourg : l’enseignement des droits de l’Homme, un parcours semé d’embûches

« Aimer ses parents, leur obéir, les respecter, leur être reconnaissant, les assister dans leur vieillesse, tels sont les principaux devoirs envers nos parents et nos grands-parents ». Voici ce que l’on enseignait le siècle dernier aux élèves préparant le certificat d’études. Ces leçons de morale, « sentences qui souvent commençaient la journée et servaient de modèles aux exercices d’écriture », ne mettaient l’accent que sur les devoirs de l’enfant : devoirs à l’égard des parents, des grands-..

Le Conseil d’Etat s’engage vers plus de transparence quant aux documents relatifs aux comptes de campagne des candidats à l’élection présidentielle

Dans un arrêt rendu le 27 mars 2015, l’Assemblée du contentieux du Conseil d’Etat a ordonné à la Commission nationale des comptes de campagne et des financements politiques (CNCCFP) la communication de documents relatifs aux comptes de campagne de M. Sarkozy lors de sa candidature à l’élection présidentielle de 2007 - sous réserve de l’occultation de certaines données nominatives -. Pour le juge, les documents en question constituent des « documents administratifs » et sont, à ce titre, soumis au régime général d’accès aux documents administratifs défini par la loi du 17 juillet 1978. Cette décision vient confirmer la position adoptée par la Commission d’accès aux documents administratifs (CADA) depuis plusieurs années

ERS International Congress 2023:highlights from the Interstitial Lung Diseases Assembly

This article summarises a selection of scientific highlights in the field of interstitial lung diseases (ILDs) presented at the International Congress of the European Respiratory Society in 2023. Translational and clinical studies focused on the whole spectrum of ILDs, from (ultra)rare ILDs to sarcoidosis, ILDs associated with connective tissue disease and idiopathic pulmonary fibrosis. The main topics of the 2023 Congress presentations were improving the diagnostic process of ILDs, better prediction of disease course and investigation of novel treatment options.</p

A subcellular tug of war involving three MYB-like proteins underlies a molecular antagonism in Antirrhinum flower asymmetry

The establishment of meristematic domains with different transcriptional activity is essential for many developmental processes. The asymmetry of the Antirrhinum majus flower is established by transcription factors with an asymmetric pattern of activity. To understand how this asymmetrical pattern is established, we studied the molecular mechanism through which the dorsal MYB protein RADIALIS (RAD) restricts the activity of the MYB transcription factor DIVARICATA (DIV) to the ventral region of the flower meristem. We show that RAD competes with DIV for binding with other MYB-like proteins, termed DRIF1 and DRIF2 (DIV- and-RAD-interacting-factors). DRIF1 and DIV interact to form a protein complex that binds to the DIV-DNA consensus region, suggesting that the DRIFs act as co-regulators of DIV transcriptional activity. In the presence of RAD, the interaction between DRIF1 and DIV bound to DNA is disrupted. Moreover, the DRIFs are sequestered in the cytoplasm by RAD, thus, preventing or reducing the formation of DRIF-DIV heterodimers in the nuclei. Our results suggest that in the dorsal region of the Antirrhinum flower meristem the dorsal protein RAD antagonises the activity of the ventral identity protein DIV in a subcellular competition for a DRIF protein promoting the establishment of the asymmetric pattern of gene activity in the Antirrhinum flower.- We are grateful to Roger Tsien for providing the plasmids with red fluorescent protein, Barry Causier and Brendan Davies for help in the screening of the Antirrhinum yeast-two hybrid library and Ulises Rosas for providing part of the cDNA sequence for DRIF2. We also thank Nicolas Arnaud and Alejandro Ferrando for providing BiFC plasmids, Desmond Bradley and Alexandra Rebocho for helpful comments on the manuscript and Lucilia Goreti Pinto and Grant Calder for helping with the confocal microscopy. This work was funded by FCT/COMPETE/FEDER with a project grant (ref. FCOMP-01-0124-FEDER-008818) and with a Royal Society International Joint Project grant (2008/R2). JR was supported by funding from FCT with a PhD grant (ref. SFRH/BD/75050/2010). The authors have no conflict of interest to declare

ERS International Congress 2021: highlights from the Interstitial Lung Diseases Assembly

This article provides an overview of scientific highlights in the field of interstitial lung disease (ILD), presented at the virtual European Respiratory Society Congress 2021. A broad range of topics was discussed this year, ranging from translational and genetic aspects to novel innovations with the potential to improve the patient pathway. Early Career Members summarise a selection of interesting findings from different congress sessions, together with the leadership of Assembly 12 - Interstitial Lung Disease. © The authors 2022

Clinical course of suspected familial and sporadic idiopathic pulmonary fibrosis: Data from the PROOF-Next registry.

peer reviewed[en] BACKGROUND AND OBJECTIVE: Real-life data on suspected familial fibrosis, defined as the occurrence of the disease in a patient younger than 50 and/or having at least one relative affected by pulmonary fibrosis remain scarce. METHODS: The Belgian and Luxembourg IPF registry (PROOF-Next) is a multicentric prospective longitudinal and observational study set in Belgium and Luxembourg. We compared characteristics and clinical course of patients with suspected familial pulmonary fibrosis (FPF) and sporadic IPF. RESULTS: We included 618 patients in the analysis, of whom 76 (12%) fulfilled criteria for FPF. They were significantly younger than sIPF (median age (range) 65 (43-87), vs. 72 (51-98), p = 0.0001). Male gender proportion and smoking status did not differ between groups, but the number of pack-year among current and former smokers was lower in FPF (20 vs. 25, p = 0.02). Besides, 87% of FPF and 76% of sIPF were treated with antifibrotic (p = 0.047). Baseline pulmonary function tests were similar in both groups, as well as median time before progression and transplant-free survival. Finally, genetic testing, performed in a minority, led to the identification of 10 telomerase-related gene variants. CONCLUSION: Although younger and exposed to less tobacco, patients with FPF show an equally aggressive progression as observed in sporadic IPF patients. These results warrant early referral of FPF patients to expert centres for optimal management

Correlation of Broncho-Alveolar Lavage Cell Count and Pulmonary Function Tests in the Era of Antifibrotics: Data from the Belgium-Luxembourg IPF registry

peer reviewe

Detection and Functional Characterization of a 215 Amino Acid N-Terminal Extension in the Xanthomonas Type III Effector XopD

During evolution, pathogens have developed a variety of strategies to suppress plant-triggered immunity and promote successful infection. In Gram-negative phytopathogenic bacteria, the so-called type III protein secretion system works as a molecular syringe to inject type III effectors (T3Es) into plant cells. The XopD T3E from the strain 85-10 of Xanthomonas campestris pathovar vesicatoria (Xcv) delays the onset of symptom development and alters basal defence responses to promote pathogen growth in infected tomato leaves. XopD was previously described as a modular protein that contains (i) an N-terminal DNA-binding domain (DBD), (ii) two tandemly repeated EAR (ERF-associated amphiphillic repression) motifs involved in transcriptional repression, and (iii) a C-terminal cysteine protease domain, involved in release of SUMO (small ubiquitin-like modifier) from SUMO-modified proteins. Here, we show that the XopD protein that is produced and secreted by Xcv presents an additional N-terminal extension of 215 amino acids. Closer analysis of this newly identified N-terminal domain shows a low complexity region rich in lysine, alanine and glutamic acid residues (KAE-rich) with high propensity to form coiled-coil structures that confers to XopD the ability to form dimers when expressed in E. coli. The full length XopD protein identified in this study (XopD1-760) displays stronger repression of the XopD plant target promoter PR1, as compared to the XopD version annotated in the public databases (XopD216-760). Furthermore, the N-terminal extension of XopD, which is absent in XopD216-760, is essential for XopD type III-dependent secretion and, therefore, for complementation of an Xcv mutant strain deleted from XopD in its ability to delay symptom development in tomato susceptible cultivars. The identification of the complete sequence of XopD opens new perspectives for future studies on the XopD protein and its virulence-associated functions in planta