HOXA1 binds RBCK1/HOIL-1 and TRAF2 and modulates the TNF/NF-κB pathway in a transcription-independent manner

HOX proteins define a family of key transcription factors regulating animal embryogenesis. HOX genes have also been linked to oncogenesis and HOXA1 has been described to be active in several cancers, including breast cancer. Through a proteome-wide interaction screening, we previously identified the TNFR-associated proteins RBCK1/HOIL-1 and TRAF2 as HOXA1 interactors suggesting that HOXA1 is functionally linked to the TNF/NF-κB signaling pathway. Here, we reveal a strong positive correlation between expression of HOXA1 and of members of the TNF/NF-κB pathway in breast tumor datasets. Functionally, we demonstrate that HOXA1 can activate NF-κB and operates upstream of the NF-κB inhibitor IκB. Consistently, we next demonstrate that the HOXA1-mediated activation of NF-κB is non-transcriptional and that RBCK1 and TRAF2 influences on NF-κB are epistatic to HOXA1. We also identify an 11 Histidine repeat and the homeodomain of HOXA1 to be required both for RBCK1 and TRAF2 interaction and NF-κB stimulation. Finally, we highlight that activation of NF-κB is crucial for HOXA1 oncogenic activity

Nontoxic Strains of Cyanobacteria Are the Result of Major Gene Deletion Events Induced by a Transposable Element

Blooms that are formed by cyanobacteria consist of toxic and nontoxic strains. The mechanisms that result in the occurrence of nontoxic strains are enigmatic. All the nontoxic strains of the filamentous cyanobacterium Planktothrix that were isolated from 9 European countries were found to have lost 90% of a large microcystin synthetase (mcy) gene cluster that encoded the synthesis of the toxic peptide microcystin (MC). Those strains still contain the flanking regions of the mcy gene cluster along with remnants of the transposable elements that are found in between. The majority of the strains still contain a gene coding for a distinct thioesterase type II (mcyT), which is putatively involved in MC synthesis. The insertional inactivation of mcyT in an MC-producing strain resulted in the reduction of MC synthesis by 94 ± 2% (1 standard deviation). Nontoxic strains that occur in shallow lakes throughout Europe form a monophyletic lineage. A second lineage consists of strains that contain the mcy gene cluster but differ in their photosynthetic pigment composition, which is due to the occurrence of strains that contain phycocyanin or large amounts of phycoerythrin in addition to phycocyanin. Strains containing phycoerythrin typically occur in deep-stratified lakes. The rare occurrence of gene cluster deletion, paired with the evolutionary diversification of the lineages of strains that lost or still contain the mcy gene cluster, needs to be invoked in order to explain the absence or dominance of toxic cyanobacteria in various habitats

Paysages de Belgique et du nord de la France. Traces et récits de la Grande Guerre

Le but de l'article est de présenter les traces de la Première Guerre mondiale laissées dans les paysages et les sols des territoires belges et du nord de la France traversés par la ligne de front

Entre vraisemblable et faux-semblants : Léopold Wartel, agent du contre-espionnage allemand en Belgique occupée durant la Première Guerre mondiale

Durant la Première Guerre mondiale, l'occupant allemand installe, en Belgique et dans le Nord de la France, une police secrète chargée de démanteler les réseaux de résistance alliés. A cette fin, et pour pallier le manque de connaissances linguistiques de ses propres agents, cette police fait appel à une série de natifs principalement belges, français et hollandais. Ceux-ci, chargés d'infiltrer les réseaux et d'en dénoncer les membres, deviennent de cette manière des agents du contre-espionnage allemand. Léopold Wartel, à Mons puis à Bruxelles, fait partie de ces individus qui se sont mis au service de l'occupant. D'abord résistant, son cas, particulièrement ambigu, témoigne de la difficulté et du caractère équivoque de cette réalité

Data-model fusion approach using tree-ring width series, a mechanistic growth model and an Earth system model to reconstruct the large-scale climate variability

Tree-ring widths represent the most commonly used proxy to reconstruct the climate of the last millennium at high resolution, thanks to their large-scale availability. The approach often relies on a relationship between tree-ring width series and climate estimated on the basis of a linear regression. However, the underlying linearity and stationarity assumptions may be inadequate and dendroclimatic process-based models may be able to overcome some of those limitations. In this thesis, we have included for the first time a dendroclimatic process-based model, MAIDEN, into a data assimilation procedure in order to improve large-scale climate reconstructions. We have first developed a protocol to calibrate and apply MAIDEN to potentially any sites with tree-ring width data in the extratropical region. We have shown that MAIDEN can be applied at global scale with a good performance and that the clear benefits obtained make it an appealing candidate for large-scale paleoclimate reconstructions. Subsequently, the MAIDEN model has been successfully incorporated into a data assimilation procedure as a proxy system model allowing a robust comparison of the outputs of an Earth system model with tree-ring width observations. The procedure has been tested to reconstruct the climate variability in the Southern Hemisphere over the last four centuries with encouraging results. Even though additional analysis are needed to fully take advantage of the new development, important steps have been made to demonstrate that using MAIDEN as a proxy system model is a promising way to improve the large-scale climate reconstructions with data assimilation.(SC - Sciences) -- UCL, 202

De la protection du secret militaire à l’occupation des populations civiles : les polices secrètes allemandes derrière le front Ouest (1914–1918)

Between 1914 and 1918, Belgium and ten departments in Northern and Eastern France were under German occupation. The imperial armies—that had set up their quarters there—as well as the civil-military occupation administration, were now in direct contact with the civilian population. In order to protect military dignitaries and military secrets, three police forces were established: (1) the Geheime Feldpolizeien attached to each army, (2) the Zentralpolizeistelle in the Generalgouvernement and (3) the Feldpolizei des Marinekorps in the area managed by the Navy. Several hundred German police officers, both professionals and neophytes, were integrated into these units, to which civil agents recruited from the local communities were also attached. Initially responsible for counterespionage, these police forces’ field of competence increased considerably during the conflict, even though they systematically lacked material and human resources to respond to the threats they perceived everywhere. The fear developed by the occupier towards the occupied led police forces to become real actors of the occupation and to intervene in situations not directly related to the protection of the army. Through the study of their structures, activities and actors, we aimed to understand how these police forces took part in the logic of occupation, which varied both in time and space and were set up by an occupier who sought first and foremost to support the Empire’s war effort.Entre 1914 et 1918, la Belgique et dix départements du nord et de l’est de la France connaissent l’occupation allemande. Les armées impériales, qui y ont installé leurs quartiers, tout comme les administrations civilo-militaires d’occupation, sont désormais directement en contact avec les populations civiles. Pour protéger les dignitaires et le secret militaires, trois forces de police sont établies : (1) les Geheime Feldpolizeien auprès de chaque armée, (2) la Zentralpolizeistelle dans le Gouvernement général et (3) la Feldpolizei des Marinekorps dans la zone gérée par la Marine. Plusieurs centaines de policiers allemands, professionnels ou néophytes, y sont intégrés, auxquels sont par ailleurs attachés des agents recrutés parmi les communautés locales. Chargées d’abord de contre-espionnage, ces polices voient leur champ de compétence considérablement augmenter au cours du conflit, alors qu’elles manquent systématiquement de moyens matériels et humains pour répondre aux menaces qu’elles perçoivent partout. La crainte que développe l’occupant à l’égard des occupés conduit les polices secrètes à devenir de réelles actrices de l’occupation et à intervenir dans des situations sans lien direct avec la protection de l'armée. À travers l’étude de leurs structures, leurs activités et des acteurs qui les composent, il s’agit de comprendre comment ces polices participent à des logiques d’occupation, variant à la fois dans le temps et dans l’espace, mises en place par un occupant qui cherche d’abord à soutenir l’effort de guerre de l’empire.(HIAR - Histoire, art et archéologie) -- UCL, 202

Clonage et caractérisation de cinq éléments d'insertion de Bacillus thuringiensis. De l'IS231 à la famille d'IS4

Doctorat en sciences biologiques -- UCL, 199