Identification et caractérisation des sous-unités ELP5 et ELP6 du complexe Elongator humain

Doctoral thesis (2013)

Familial Dysautonomia is a neurodegenerative disorder that affects the autonomic and sensory nervous systems. This disease results from loss-of-function mutations of the ELP1-encoding gene. ELP1 is ... [more ▼]

Familial Dysautonomia is a neurodegenerative disorder that affects the autonomic and sensory nervous systems. This disease results from loss-of-function mutations of the ELP1-encoding gene. ELP1 is required for the integrity of the so-called Elongator complex, which is composed of two sub-proteins complexes, namely the core-Elongator (ELP1 to ELP3) and HAP (ELP4 to ELP6). While ELP3 is acting as an acetyltransferase that target multiple substrates such as nuclear histones and cytoplasmic α-tubulin, the ELP4-6 has been recently described as an ATPase. This complex has been initially identified as a component of a hyperphosphorylated RNA polymerase II holoenzyme. As a result, Elongator is involved in transcriptional elongation. Since, other roles have been assigned. Elongator is indeed also required for some tRNA modifications in the cytoplasm and consequently controls translation fidelity. Those molecular functions underlie the capacity of Elongator to regulate cell division, DNA-damage response and cell motility. It is likely that a better understanding of the molecular functions of Elongator will clarify its role in these cellular processes and probably highlight new features. The identity of human ELP1 through ELP4 has been reported but human ELP5 and ELP6 have remained uncharacterized. We therefore initiated a study dedicated to the identification and characterization of both proteins. A biochemical purification of ELP4 was conducted to isolate all associated proteins. Such experimental approach led to the identification of DERP6 and C3ORF75 as human ELP5 and ELP6 subunits of the Elongator complex, respectively. We further investigated the cellular functions of both subunits by combining biochemical analysis and cellular assays. Our results show that DERP6/Elp5 is required for the integrity and the fucntion of Elongator and directly connects ELP3 to ELP4. Our laboratory has previously demonstrated the key role of Elongator in cell migration. As cell motility is required for cell invasion and metastasis, we therefore investigated to which extent Elongator is involved in those processes. The migration and tumorigenicity of melanoma-derived cells are significantly decreased upon Elongator invalidation through Elp1 or Elp3 depletion. Strikingly, DERP6/Elp5 and C3ORF75/Elp6-depleted melanoma cells have similar defects, further supporting the idea that DERP6/Elp5 and C3ORF75/Elp6 are essential for Elongator function. Together, our data identify DERP6/ELP5 and C3ORF75/ELP6 as key players for migration, invasion and tumorigenicity of melanoma cells, as integral subunits of Elongator. [less ▲]

Analytical evaluation of virgin olive oils produced from three varieties Koroneiki , Arbequina and Arbosana grown in east of Morocco

Poster (2013, April)

When does the Market feel it? Magnitude, speed and persistence of market reactions to of cross-listings

E-print/Working paper (2013)

La gestion de la qualité de l’air en Belgique : une gouvernance multiniveau entre incertitudes politiques et techniques

in Telescope (2013), 19(hiver),

La gouvernance de l’État belge est caractérisée par un double processus de reconfiguration : vers le haut, par les dynamiques d’européanisation, et vers le bas, par un processus de régionalisation ... [more ▼]

La gouvernance de l’État belge est caractérisée par un double processus de reconfiguration : vers le haut, par les dynamiques d’européanisation, et vers le bas, par un processus de régionalisation approfondi. Par exemple, le domaine de l’environnement est aujourd’hui régionalisé, mais de nombreuses décisions sont prises au niveau de l’Union européenne, dont les instances décisionnelles n’intègrent pas pleinement le fait régional. Cet article s’appuie sur une étude menée auprès des instances fédérales et régionales chargées de la gestion de la qualité de l’air en Belgique. La traduction du cadre européen demanderait le déploiement d’une approche transversale environnement-santé associant tous les niveaux de pouvoir, mais les répondants dénoncent l’absence d’intégration de ces politiques aux niveaux régional et fédéral. Chaque niveau de pouvoir développe une dynamique propre pour réinterpréter la politique et les instruments définis au niveau européen. [less ▲]

Quadratization of symmetric pseudo-Boolean functions

Conference (2013, April)

We consider the problem of minimizing an arbitrary pseudo-Boolean function f(x), that is, a real-valued function of 0-1 variables. In recent years, several authors have proposed to reduce this problem to ... [more ▼]

We consider the problem of minimizing an arbitrary pseudo-Boolean function f(x), that is, a real-valued function of 0-1 variables. In recent years, several authors have proposed to reduce this problem to the quadratic case by expressing f(x) as min{g(x,y):y∈{0,1}^m}, where g(x,y) is a quadratic pseudo-Boolean function of x and of additional binary variables y. We say that g(x,y) is a quadratization of f. In this talk, we investigate the number of additional variables needed in a quadratization when f is a symmetric function of the x-variables. The cases where f is either a positive or a negative monomial are of particular interest, but some of our techniques also extend to more complex functions, like k-out-of-n or parity functions. Joint work with Martin Anthony, Endre Boros and Aritanan Gruber [less ▲]

Carnet de pédiatrie: propédeutique clinique et d'imagerie

Learning material (2013)

Platelet-rich plasma (PRP) to treat chronic upper patellar tendinopathies

in Abstract Book of the 3rd Congress of the ECOSEP (2013, April)

Background: Upper patellar tendinopathies remain often chronic and rebel to a thorough conservative treatment. Moreover, the option of a surgical treatment could be disappointing. New treatments are being ... [more ▼]

Background: Upper patellar tendinopathies remain often chronic and rebel to a thorough conservative treatment. Moreover, the option of a surgical treatment could be disappointing. New treatments are being developed. Injection of PRP is one of these. Platelets contain lot of growth factors which would have the potentiality to enhance the healing process of tendons. Even if in vitro and animal experiments have demonstrated this stimulation of tendon healing process1, clinical series are subject to controversy2. Methods: Twenty patients with chronic upper patellar tendinopathy were enrolled. Assessments ［VAS, clinical examination with an algometer, algofunctional scores (IKDC and VISA-P), functional assessments (isokinetic and Optojump) and imagery (ultrasounds and MRI)］were made before infiltration of PRP, and 6 weeks and 3 months after. The PRP was obtained by an apheresis system (COM.TEC, Fresenius). Six millilitres of PRP were injected without local anaesthetic. One week after infiltration, patients started a 6-week standardised sub-maximal eccentric reeducation. Results: We observed a very significant improvement of the algofunctional status as soon as 6 weeks after the infiltration of PRP, and continued to a lesser extent up to 3 months. During functional evaluation, pain decreased as well, but without significant improvement of performances. No significant improvements in the imagery were observed. Interestingly, patients who had a VAS equal or below 1 after 3 months post-infiltration were younger (24.7 vs 32.2 y.o.). Moreover, these younger patients had a significant increase of the IKDC score (p=0.003), a significant improvement of pain during isokinetic evaluations (p<0.05), and during Optojump assessments (p=0.01). Seventy-five percent of subjects were able to return to sport, even if only half of these patients recovered the same level than before the tendinopathy. Discussion / Conclusions: This study demonstrates that a local infiltration of PRP associated with a submaximal eccentric protocol is efficient to improve symptoms of chronic upper patellar tendinopathies, non-responsive to classical conservative treatments. However, up to now, there is no consensus on the method to prepare the PRP. Indeed, each technique could provide a very different PRP (variations in the platelet concentrations and of the amount of red and white cells). [less ▲]

Regard scientifique sur l'écrivain Hubert Nyssen

Article for general public (2013)

Interview par Henri Deleersnijder à propos de la réédition du Nom de l'arbre (Espace Nord) et de la journée d'étude du 8 mai 2013, "Les écritures d'Hubert Nyssen"

FAO Training in Crop Yield Forecasting. Improvement of the Crop Yield Forecasting System (CYFS) in Armenia: a new approach for satellite data integration. ARMENIA - Yerevan - January 2013.

Learning material (2013)

This manual describes a methodology to prepare the remote sensing database needed for the crop yield forecasting methodology developped by the University of Liege, in the case of Armenia.This manual has ... [more ▼]

This manual describes a methodology to prepare the remote sensing database needed for the crop yield forecasting methodology developped by the University of Liege, in the case of Armenia.This manual has been written for the training in Crop Yield Forecasting for Armenia that occurred between 21st and 25th January 2013 in Erevan – Armenia in the framework of the “EC/FAO Programme on information systems to improve food security decision-making in the European Neighbourhood Policy (ENP) East area”. This manual is intended to cover the Remote Sensing part only of the general CYFS. Despite written for the Armenian training this manual can serve as an example for all other countries. [less ▲]

Clauses d'élection de for et procédures concurrentes : les nouveautés du Règlement Bruxelles Ibis

Conference (2013, April)

Ces documents constituent le support de présentation utilisé lors d'une conférence consacrée au Règlement Bruxelles Ibis. Ils font le point sur les nouveautés apportées au régime des clauses d'élection de ... [more ▼]

Ces documents constituent le support de présentation utilisé lors d'une conférence consacrée au Règlement Bruxelles Ibis. Ils font le point sur les nouveautés apportées au régime des clauses d'élection de for ainsi qu'au traitement réservé aux procédures concurrentes [less ▲]