References of "Meuwis, Marie-Alice"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailTNFa and IKKb-mediated TANK/I-TRAF phosphorylation: implications for interaction with NEMO/IKKg and NF-kB activation
Bonif, Marianne; Meuwis, Marie-Alice ULg; Close, Pierre ULg et al

in Biochemical Journal (2006), 394

Pro-inflammatory cytokines trigger signalling cascades leading to NF-kappaB (nuclear factor-kappaB)-dependent gene expression through IKK [IkappaB (inhibitory kappaB) kinase]-dependent phosphorylation and ... [more ▼]

Pro-inflammatory cytokines trigger signalling cascades leading to NF-kappaB (nuclear factor-kappaB)-dependent gene expression through IKK [IkappaB (inhibitory kappaB) kinase]-dependent phosphorylation and subsequent degradation of the IkappaB proteins and via induced phosphorylation of p65. These signalling pathways rely on sequentially activated kinases which are assembled by essential and non-enzymatic scaffold proteins into functional complexes. Here, we show that the pro-inflammatory cytokine TNFalpha (tumour necrosis factor alpha) promotes TANK [TRAF (TNF receptor-associated factor) family member associated NF-kappaB activator] recruitment to the IKK complex via a newly characterized C-terminal zinc finger. Moreover, we show that TANK is phosphorylated by IKKbeta upon TNFalpha stimulation and that this modification negatively regulates TANK binding to NEMO (NF-kappaB essential modulator). Interestingly, reduced TANK expression by RNA interference attenuates TNFalpha-mediated induction of a subset of NF-kappaB target genes through decreased p65 transactivation potential. Therefore the scaffold protein TANK is required for the cellular response to TNFalpha by connecting upstream signalling molecules to the IKKs and p65, and its subsequent IKKbeta-mediated phosphorylation may be a mechanism to terminate the TANK-dependent wave of NF-kappaB activation. [less ▲]

Detailed reference viewed: 70 (9 ULg)
Full Text
Peer Reviewed
See detailProteomic mass spectra classification using decision tree based ensemble methods.
Geurts, Pierre ULg; Fillet, Marianne ULg; De Seny, Dominique ULg et al

in Bioinformatics (2005), 21(14), 3138-45

MOTIVATION: Modern mass spectrometry allows the determination of proteomic fingerprints of body fluids like serum, saliva or urine. These measurements can be used in many medical applications in order to ... [more ▼]

MOTIVATION: Modern mass spectrometry allows the determination of proteomic fingerprints of body fluids like serum, saliva or urine. These measurements can be used in many medical applications in order to diagnose the current state or predict the evolution of a disease. Recent developments in machine learning allow one to exploit such datasets, characterized by small numbers of very high-dimensional samples. RESULTS: We propose a systematic approach based on decision tree ensemble methods, which is used to automatically determine proteomic biomarkers and predictive models. The approach is validated on two datasets of surface-enhanced laser desorption/ionization time of flight measurements, for the diagnosis of rheumatoid arthritis and inflammatory bowel diseases. The results suggest that the methodology can handle a broad class of similar problems. [less ▲]

Detailed reference viewed: 65 (17 ULg)
Full Text
Peer Reviewed
See detailDiscovery of new rheumatoid arthritis biomarkers using the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry ProteinChip approach.
De Seny, Dominique ULg; Fillet, Marianne ULg; Meuwis, Marie-Alice ULg et al

in Arthritis and Rheumatism (2005), 52(12), 3801-12

OBJECTIVE: To identify serum protein biomarkers specific for rheumatoid arthritis (RA), using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) technology ... [more ▼]

OBJECTIVE: To identify serum protein biomarkers specific for rheumatoid arthritis (RA), using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) technology. METHODS: A total of 103 serum samples from patients and healthy controls were analyzed. Thirty-four of the patients had a diagnosis of RA, based on the American College of Rheumatology criteria. The inflammation control group comprised 20 patients with psoriatic arthritis (PsA), 9 with asthma, and 10 with Crohn's disease. The noninflammation control group comprised 14 patients with knee osteoarthritis and 16 healthy control subjects. Serum protein profiles were obtained by SELDI-TOF-MS and compared in order to identify new biomarkers specific for RA. Data were analyzed by a machine learning algorithm called decision tree boosting, according to different preprocessing steps. RESULTS: The most discriminative mass/charge (m/z) values serving as potential biomarkers for RA were identified on arrays for both patients with RA versus controls and patients with RA versus patients with PsA. From among several candidates, the following peaks were highlighted: m/z values of 2,924 (RA versus controls on H4 arrays), 10,832 and 11,632 (RA versus controls on CM10 arrays), 4,824 (RA versus PsA on H4 arrays), and 4,666 (RA versus PsA on CM10 arrays). Positive results of proteomic analysis were associated with positive results of the anti-cyclic citrullinated peptide test. Our observations suggested that the 10,832 peak could represent myeloid-related protein 8. CONCLUSION: SELDI-TOF-MS technology allows rapid analysis of many serum samples, and use of decision tree boosting analysis as the main statistical method allowed us to propose a pattern of protein peaks specific for RA. [less ▲]

Detailed reference viewed: 65 (9 ULg)
See detailDiscovery of new rheumatoid arthritis biomarkers using SELDI-TOF-MS ProteinChip approach
de Seny, D. M.; Fillet, Marianne ULg; Meuwis, Marie-Alice ULg et al

in Arthritis and Rheumatism (2004, September), 50(9, Suppl. S), 124

Detailed reference viewed: 33 (11 ULg)
Full Text
Peer Reviewed
See detailActivity, stability and flexibility in Glycosidases adapted to extreme thermal environments
Collins, T.; Meuwis, Marie-Alice ULg; Gerday, Charles ULg et al

in Journal of Molecular Biology (2003), 328(2), 419-428

To elucidate the strategy of low temperature adaptation for a cold-adapted family 8 xylanase, the thermal and chemical stabilities, thermal inactivation, thermodependence of activity and conformational ... [more ▼]

To elucidate the strategy of low temperature adaptation for a cold-adapted family 8 xylanase, the thermal and chemical stabilities, thermal inactivation, thermodependence of activity and conformational flexibility, as well as the thermodynamic basis of these processes, were compared with those of a thermophilic homolog. Differential scanning calorimetry, fluorescence monitoring of guanidine hydrochloride unfolding and fluorescence quenching were used, among other techniques, to show that the cold-adapted enzyme is characterized by a high activity at low temperatures, a poor stability and a high flexibility. In contrast, the thermophilic enzyme is shown to have a reduced low temperature activity, high stability and a reduced flexibility. These findings agree with the hypothesis that cold-adapted enzymes overcome the quandary imposed by low temperature environments via a global or local increase in the flexibility of their molecular edifice, with this in turn leading to a reduced stability. Analysis of the guanidine hydrochloride unfolding, as well as the thermodynamic parameters of irreversible thermal unfolding and thermal inactivation shows that the driving force for this denaturation and inactivation is a large entropy change while a low enthalpy change is implicated in the low temperature activity. A reduced number of salt-bridges are believed to be responsible for both these effects. Guanidine hydrochloride unfolding studies also indicate that both family 8 enzymes unfold via an intermediate prone to aggregation. (C) 2003 Elsevier Science Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailThe structure of a cold-adapted family 8 xylanase at 1.3 angstrom resolution - Structural adaptations to cold and investigation of the active site
Van Petegem, F.; Collins, T.; Meuwis, Marie-Alice ULg et al

in Journal of Biological Chemistry (2003), 278(9), 7531-7539

Enzymes from psychrophilic organisms differ from their mesophilic counterparts in having a lower thermo-stability and a higher specific activity at low and moderate temperatures. The current consensus is ... [more ▼]

Enzymes from psychrophilic organisms differ from their mesophilic counterparts in having a lower thermo-stability and a higher specific activity at low and moderate temperatures. The current consensus is that they have an increased flexibility, enhancing accommodation and transformation of the substrates at low energy costs. Here we describe the structure of the xylanase from the Antarctic bacterium Pseudoalteromonas haloplanktis at 1.3 Angstrom resolution. Xylanases are usually grouped into glycosyl hydrolase families 10 and 11, but this enzyme belongs to family 8. The fold differs from that of other known xylanases and can be described as an (alpha/alpha)(6) barrel. Various parameters that may explain the cold-adapted properties were examined and indicated that the protein has a reduced number of salt bridges and an increased exposure of hydrophobic residues. The crystal structures of a complex with xylobiose and of mutant D144N were obtained at 1.2 and 1.5 A resolution, respectively. Analysis of the various substrate binding sites shows that the +3 and -3 subsites are rearranged as compared to those of a family 8 homolog, while the xylobiose complex suggests the existence of a +4 subsite. A decreased acidity of the substrate binding cleft and an increased flexibility of aromatic residues lining the subsites may enhance the rate at which substrate is bound. [less ▲]

Detailed reference viewed: 5 (1 ULg)
Full Text
Peer Reviewed
See detailA novel family 8 xylanase, functional and physicochemical characterization
Collins, T.; Meuwis, Marie-Alice ULg; Stals, I. et al

in Journal of Biological Chemistry (2002), 277(38), 35133-35139

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailCrystallization and preliminary X-ray analysis of a xylanase from the psychrophile Pseudoalteromonas haloplanktis
Van Petegem, F.; Collins, T.; Meuwis, Marie-Alice ULg et al

in Acta Crystallographica Section D-Biological Crystallography (2002), 58(Part 9), 1494-1496

The 46 kDa xylanase from the Antarctic microorganism Pseudoalteromonas haloplanktis is an enzyme that efficiently catalyzes reactions at low temperatures. Here, the crystallization of both the native ... [more ▼]

The 46 kDa xylanase from the Antarctic microorganism Pseudoalteromonas haloplanktis is an enzyme that efficiently catalyzes reactions at low temperatures. Here, the crystallization of both the native protein and the SeMet-substituted enzyme and data collection from both crystals using synchrotron radiation are described. The native data showed that the crystals diffract to 1.3 Angstrom resolution and belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 50.87, b = 90.51, c = 97.23 Angstrom. SAD data collected at the peak of the selenium absorption edge proved to be sufficient to determine the heavy-atom configuration and to obtain electron density of good quality. [less ▲]

Detailed reference viewed: 9 (1 ULg)
Full Text
Peer Reviewed
See detailMolecular basis of cold adaptation
D'Amico, Salvino ULg; Claverie, P.; Collins, T. et al

in Philosophical Transactions of the Royal Society of London Series B-Biological Sciences (2002), 357(1423), 917-924

Cold-adapted, or psychrophilic, organisms are able to thrive at low temperatures in permanently cold environments, which in fact characterize the greatest proportion of our planet. Psychrophiles include ... [more ▼]

Cold-adapted, or psychrophilic, organisms are able to thrive at low temperatures in permanently cold environments, which in fact characterize the greatest proportion of our planet. Psychrophiles include both prokaryotic and eukaryotic organisms and thus represent a significant proportion of the living world. These organisms produce cold-evolved enzymes that are partially able to cope with the reduction in chemical reaction rates induced by low temperatures. As a rule, cold-active enzymes display a high catalytic efficiency, associated however, with a low thermal stability. In most cases, the adaptation to cold is achieved through a reduction in the activation energy that possibly originates from an increased flexibility of either a selected area or of the overall protein structure. This enhanced plasticity seems in turn to be induced by the weak thermal stability of psychrophilic enzymes. The adaptation strategies are beginning to be understood thanks to recent advances in the elucidation of the molecular characteristics of cold-adapted enzymes derived from X-ray crystallography, protein engineering and biophysical methods. Psychrophilic organisms and their enzymes have, in recent years, increasingly attracted the attention of the scientific community due to their peculiar properties that render them particularly useful in investigating the possible relationship existing between stability, flexibility and specific activity and as valuable tools for biotechnological purposes. [less ▲]

Detailed reference viewed: 23 (2 ULg)
See detailLife in the cold: psychrophilic enzymes
Collins, T.; Claverie, P.; D'Amico, Salvino ULg et al

in Recent Res. Devl. Proteins vol. 1 (2002)

Detailed reference viewed: 30 (2 ULg)
Full Text
Peer Reviewed
See detailDid Psychrophilic Enzymes Really Win the Challenge?
Zecchinon, Laurent ULg; Claverie, P.; Collins, T. et al

in Extremophiles : Life Under Extreme Conditions (2001), 5(5), 313-21

Organisms living in permanently cold environments, which actually represent the greatest proportion of our planet, display at low temperatures metabolic fluxes comparable to those exhibited by mesophilic ... [more ▼]

Organisms living in permanently cold environments, which actually represent the greatest proportion of our planet, display at low temperatures metabolic fluxes comparable to those exhibited by mesophilic organisms at moderate temperatures. They produce cold-evolved enzymes partially able to cope with the reduction in chemical reaction rates and the increased viscosity of the medium induced by low temperatures. In most cases, the adaptation is achieved through a reduction in the activation energy, leading to a high catalytic efficiency, which possibly originates from an increased flexibility of either a selected area of or the overall protein structure. This enhanced plasticity seems in return to be responsible for the weak thermal stability of cold enzymes. These particular properties render cold enzymes particularly useful in investigating the possible relationships existing between stability, flexibility, and specific activity and make them potentially unrivaled for numerous biotechnological tasks. In most cases, however, the adaptation appears to be far from being fully achieved. [less ▲]

Detailed reference viewed: 22 (0 ULg)
See detailA novel family 8 xylanase : characteristics and evolutionary aspects
Collins, Tony; Meuwis, Marie-Alice ULg; Feller, Georges ULg et al

Poster (2001)

Detailed reference viewed: 8 (0 ULg)
See detailCold-adapted enzymes: an unachieved symphony
D'Amico, Salvino ULg; Claverie, P.; Collins, T. et al

in Storey, K. B.; Storey, J. M. (Eds.) Cell and Molecular Responses to Stress vol.2. Protein adaptations and signal transduction, (2001)

Detailed reference viewed: 37 (3 ULg)
See detailCold-adapted enzymes
Georlette, D.; Bentahir, M.; Claverie, P. et al

in Bulte, J.; DeCuyper, M. (Eds.) Focus on Biotechnology – Physics and Chemistry Basis for Biotechnology (2001)

Detailed reference viewed: 20 (2 ULg)
Full Text
Peer Reviewed
See detailCold-Adapted Enzymes: From Fundamentals to Biotechnology
Gerday, Charles ULg; Aittaleb, Mohamed; Bentahir, Mostafa et al

in Trends in Biotechnology (2000), 18(3), 103-7

Psychrophilic enzymes produced by cold-adapted microorganisms display a high catalytic efficiency and are most often, if not always, associated with high thermosensitivity. Using X-ray crystallography ... [more ▼]

Psychrophilic enzymes produced by cold-adapted microorganisms display a high catalytic efficiency and are most often, if not always, associated with high thermosensitivity. Using X-ray crystallography, these properties are beginning to become understood, and the rules governing their adaptation to cold appear to be relatively diverse. The application of these enzymes offers considerable potential to the biotechnology industry, for example, in the detergent and food industries, for the production of fine chemicals and in bioremediation processes. [less ▲]

Detailed reference viewed: 59 (3 ULg)