Aerobic Lineage of the Oxidative Stress Response Protein Rubrerythrin Emerged in an Ancient Microaerobic, (Hyper)Thermophilic Environment

Indexación: Web of Science; Scopus.Rubrerythrins (RBRs) are non-heme di-iron proteins belonging to the ferritin-like superfamily. They are involved in oxidative stress defense as peroxide scavengers in a wide range of organisms. The vast majority of RBRs, including classical forms of this protein, contain a C-terminal rubredoxin-like domain involved in electron transport that is used during catalysis in anaerobic conditions. Rubredoxin is an ancient and large protein family of short length (<100 residues) that contains a Fe-S center involved in electron transfer. However, functional forms of the enzyme lacking the rubredoxin-like domain have been reported (e.g., sulerythrin and ferriperoxin). In this study, phylogenomic evidence is presented that suggests that a complete lineage of rubrerythrins, lacking the rubredoxin-like domain, arose in an ancient microaerobic and (hyper)thermophilic environments in the ancestors of the Archaea Thermoproteales and Sulfolobales. This lineage (termed the "aerobic-type" lineage) subsequently evolved to become adapted to environments with progressively lower temperatures and higher oxygen concentrations via the acquisition of two co-localized genes, termed DUF3501 and RFO, encoding a conserved protein of unknown function and a predicted Fe-S oxidoreductase, respectively. Proposed Horizontal Gene Transfer events from these archaeal ancestors to Bacteria expanded the opportunities for further evolution of this RBR including adaption to lower temperatures. The second lineage (termed the cyanobacterial lineage) is proposed to have evolved in cyanobacterial ancestors, maybe in direct response to the production of oxygen via oxygenic photosynthesis during the Great Oxygen Event (GOE). It is hypothesized that both lineages of RBR emerged in a largely anaerobic world with "whiffs" of oxygen and that their subsequent independent evolutionary trajectories allowed microorganisms to transition from this anaerobic world to an aerobic one.http://journal.frontiersin.org/article/10.3389/fmicb.2016.01822/ful

Regulation of NKG2D-Dependent NK Cell Functions: The Yin and the Yang of Receptor Endocytosis.

Natural-killer receptor group 2, member D (NKG2D) is a well characterized natural killer (NK) cell activating receptor that recognizes several ligands poorly expressed on healthy cells but up-regulated upon stressing stimuli in the context of cancer or viral infection. Although NKG2D ligands represent danger signals that render target cells more susceptible to NK cell lysis, accumulating evidence demonstrates that persistent exposure to ligand-expressing cells causes the decrease of NKG2D surface expression leading to a functional impairment of NKG2D-dependent NK cell functions. Upon ligand binding, NKG2D is internalized from the plasma membrane and sorted to lysosomes for degradation. However, receptor endocytosis is not only a mechanism of receptor clearance from the cell surface, but is also required for the proper activation of signalling events leading to the functional program of NK cells. This review is aimed at providing a summary of current literature relevant to the molecular mechanisms leading to NKG2D down-modulation with particular emphasis given to the role of NKG2D endocytosis in both receptor degradation and signal propagation. Examples of chronic ligand-induced down-regulation of NK cell activating receptors other than NKG2D, including natural cytotoxicity receptors (NCRs), DNAX accessory molecule-1 (DNAM1) and CD16, will be also discussed

A bacterial consortium for treatment of Fat, Oil, and Grease (FOGs) in wastewater treatment plants

Fats, oils and greases (FOG), CER 190809, in wastewater create problems including the production of foul odours, the blockage of sewer lines and interference with the proper operation of sewage treatment works. Removal of FOG is thus critically important to ensure that wastewater is disposed of efficiently and economically. In this study, 232 bacterial strains were isolated and screened for the ability to degrade lipids from a specialized treatment plant, where a enhanced FOG degradation activity had been detected. Enrichment cultures on oily substrates, followed by isolation on selective media for lipase producing bacteria, and enzymatic methods were used to screen lipolytic microorganisms. In a second step, the lipolytic bacteria were analyzed using a colorimetric assay to detect the transesterification activity of para-nitrophenyl-palmitate. Four best performing lipid-degrading bacteria were identified by 16SrDNA sequencing, and investigated for application in treatment of lipids-contaminated wastewater, in Sequencing Batch Reactor (SBR) pilot plant. The FOG biodegradation efficiency was evaluated after 10 days using the gravimetric method for quantitative determination of total oily substances. The bacterial strains were Gram negative affiliated to Serratia, Aeromonas, Pedobacter genera. The Bacterial consortium was able to degrade 76% of FOG in 10 days treatment. The strains are be of great interest at industrial scale to increase the removal of FOG in wastewater treatment plants, and directly in the waste storage tanks at catering establishments, to reduce the polluting load before transfer to the disposal plan. The process of bioaugmentation using the FOG degrading consortium was recently patented (n°812021000056699

Inferences and Dialogues in Ludics

International audience– We propose to use Ludics as a unified framework for the analysis of dialogue and as a reasoning system. Not only Ludics gives a denotational semantics for Linear Logic, but it uses interaction as a primitive notion. We first sketch a model for pragmatical and rhetorical aspects of dialogue after a brief review of the way the interactive aspect of dialogue may be represented in Ludics. Then we show how taking into account inferences that occur during a dialogue, with respect to a ISU-like model of dialogue. Through various examples we give an analysis of deductive inferences as well as processes making facts explicit that take place during knowledge updating

Coronary artery-pulmonary artery fistula: case report

BACKGROUND: Coronary artery fistulas are rare congenital or acquired coronary artery anomalies that can originate from any of the three major coronary arteries and drain in all the cardiac chambers and great vessels. CASE PRESENTATION: An 11-year-old boy was referred for evaluation of an exertional dyspnoea. He reported recent history of few episodes of shortness of breath associated with moderate entity physical activity. At physical examination a mild continuous murmur could be heard mainly at the level of the second intercostal space of the left parasternal area. A transthoracic echocardiogram showed a continuous flow at color Doppler analysis in the high parasternal short axis view, originating from a small entry site on the wall of the main pulmonary artery. A selective left coronary angiography revealed a fistula connecting the proximal portion of the left anterior descending coronary artery with the main pulmonary artery. CONCLUSION: A combination like the one described in the present case is unusual since fistulas originate from the left coronary artery in about 35% of cases and drainage into the pulmonary artery occurs in only 17%

Une introduction à la Ludique et à ses applications à la Pragmatique

Ce texte, écrit avec l'aide de spécialistes de la ludique (Marie-Renée Fleury et Myriam Quatrini) introduit à ce difficile sujet. En résumé, la ludique est une nouvelle manière de penser la logique, imaginée par Jean-Yves Girard, qui tente de dépasser le dualisme bien connu entre les preuves (objets syntaxiques) et les modèles (objets sémantiques). En ludique, les preuves s'opposent à des contre-preuves, le tout pouvant être subsumé sous le concept général d'épreuves (appellation proposée par Pierre Livet). On retrouve alors des notions mathématiques générales comme celle d'orthogonalité qui permettent de dessiner l'espace des "disputes". Les figures ainsi obtenues, appelées "dessins", peuvent être interprétées en termes de jeu et sont alors vues aussi comme des "desseins". La logique qu'on espère trouver au terme de cette exploration est celle qui possède les dessins les plus simples et les plus convaincants. Elle peut être la logique linéaire ou une de ses variantes (logique affine?). Le point de vue présenté dans ce papier introductif, qui sert de base à un programme financé par l'ANR (PRELUDE) est qu'on peut trouver dans la ludique un fondement commun à la logique et à la pragmatique des dialogues

ILC3s: Rhythmic Keepers of Gut Integrity at Mealtime

Cyclically, during the day, increased permeability of the intestinal epithelial barrier, allowing nutrient uptake, must be compensated for, to achieve increased protection against potentially harmful components. Seillet et al. demonstrate that, upon food intake, enteric neuron-derived VIP promotes anticipatory mucosal immunity by inducing ILC3s to produce protective IL-22