Crystal structure of the cold-active aminopeptidase from Colwellia psychrerythraea, a close structural homologue of the human bifunctional leukotriene A4 hydrolase

peer reviewedThe crystal structure of a cold-active aminopeptidase (ColAP) from Colwellia psychrerythraea strain 34H has been determined, extending the number of crystal structures of the M1 metallopeptidase family to four among the 436 members currently identified. In agreement with their sequence similarity, the overall structure of ColAP displayed a high correspondence with leukotriene A4 hydrolase (LTA4H), a human bifunctional enzyme that converts leukotriene A4 (LTA4) in the potent chemoattractant leukotriene B4. Indeed, both enzymes are composed of three domains, an N-terminal saddle-like domain, a catalytic thermolysin-like domain, and a less conserved C-terminal alpha-helical flat spiral domain. Together, these domains form a deep cavity harboring the zinc binding site formed by residues included in the conserved HEXXHX(18)H motif. A detailed structural comparison of these enzymes revealed several plausible determinants of ColAP cold adaptation. The main differences involve specific amino acid substitutions, loop content and solvent exposure, complexity and distribution of ion pairs, and differential domain flexibilities. Such elements may act synergistically to allow conformational flexibility needed for an efficient catalysis in cold environments. Furthermore, the region of ColAP corresponding to the aminopeptidase active site of LTA4H is much more conserved than the suggested LTA4 substrate binding region. This observation supports the hypothesis that this region of the LTA4H active site has evolved in order to fit the lipidic substrate

Arrest of mammalian fibroblasts in G1 in response to actin inhibition is dependent on retinoblastoma pocket proteins but not on p53

p53 and the retinoblastoma (RB) pocket proteins are central to the control of progression through the G1 phase of the cell cycle. The RB pocket protein family is downstream of p53 and controls S-phase entry. Disruption of actin assembly arrests nontransformed mammalian fibroblasts in G1. We show that this arrest requires intact RB pocket protein function, but surprisingly does not require p53. Thus, mammalian fibroblasts with normal pocket protein function reversibly arrest in G1 on exposure to actin inhibitors regardless of their p53 status. By contrast, pocket protein triple knockout mouse embryo fibroblasts and T antigen–transformed rat embryo fibroblasts lacking both p53 and RB pocket protein function do not arrest in G1. Fibroblasts are very sensitive to actin inhibition in G1 and arrest at drug concentrations that do not affect cell adhesion or cell cleavage. Interestingly, G1 arrest is accompanied by inhibition of surface ruffling and by induction of NF2/merlin. The combination of failure of G1 control and of tetraploid checkpoint control can cause RB pocket protein–suppressed cells to rapidly become aneuploid and die after exposure to actin inhibitors, whereas pocket protein–competent cells are spared. Our results thus establish that RB pocket proteins can be uniquely targeted for tumor chemotherapy

Inventaire Et Identification Des Dégâts Des Insectes Infestant Les Plants De Manioc (Manihot Esculenta Crantz) À Deux Et Huit Mois Après Plantation Et Essai De Lutte Biologique Dans La Localité De Daloa (Côte d’Ivoire)

Le manioc est devenu un aliment de base des populations de Côte d’Ivoire. La présente étude qui lui est consacrée a été réalisée dans la période d'avril à octobre 2020 et avait pour objectif d'établir l'inventaire de l'entomofaune qui lui est associée, trouver leurs dégâts afin de mettre en place une stratégie de lutte pouvant réduire ces pathogènes. Cette étude a été réalisée sur deux variétés de manioc : Bocou 1 et Yavo. Plusieurs méthodes ont été utilisées pour la collecte des insectes à savoir : le piégeage, la capture à la main et au filet fauchoir. Les résultats ont montré une entomofaune très diversifiée avec 12 ordres d’insectes parmi lesquels il peut être cité : les Hétéroptères (les plus nombreux), suivis des Diptères, des Thysanoptères, des Coléoptères, des Hyménoptères et des Orthoptères. Ces insectes ravageurs sont vecteurs de plusieurs maladies dont la virose avec une incidence de 38,88% chez la variété Bocou 1, la bactériose avec une incidence de 85,55% chez la variété Yavo et 67,77% chez la variété Bocou 1. La solution aqueuse à base de neem a été également utilisée afin de lutter contre ces ravageurs. Cette solution s’est montrée efficace contre les insectes ravageurs des cultures de manioc. Cette étude a donc permis de faire l'inventaire de quelques insectes associés au manioc dans cette localité et d’établir une méthode de lutte biologique. Cassava has become a staple food for people in Côte d'Ivoire. The present study devoted to it was carried out in the period from April to October  and aims to establish an inventory of the entomofauna associated with it, to find their damage in order to set up a control strategy that can reduce these pathogens. This study was carried out on two varieties of cassava: Bocou 1 and Yavo. Several methods were used for the collection of insects namely: trapping, capture by hand and with a hay net. The results showed a very diverse entomofauna with 12 orders of insects among which we can cite: Heteroptera, the most numerous, followed by Diptera, Thysanoptera, Coleoptera, Hymenoptera, Orthoptera. These insect pests are vectors of several diseases including virosis with an incidence of 38.88% in variety Bocou 1, bacteriosis with an incidence of 85.55% in variety Yavo and 67.77% in variety Bocou 1. The aqueous solution based on neem has also been used to control these pests. This solution has been shown to be effective against insect pests of cassava crops. This study therefore made it possible to make an inventory of some insects associated with cassava in this locality and to establish a method of biological control

Diagnostic value of cone beam computed tomography (CBCT) in occult scaphoid and wrist fractures

OBJECTIVE: Evaluate the diagnostic value of cone beam computed tomography (CBCT) for scaphoid and wrist fractures that are missed on standard radiographs. MATERIALS AND METHODS: Between September 2014 and October 2015, we prospectively enrolled 49 patients with a clinically suspected scaphoid fracture following an acute injury but had normal radiographs. Each patients underwent radiographs, CBCT and (magnetic resonance imaging) MRI within 7days of the initial injury event. Both exam were evaluated independently by two radiologists. RESULTS: For scaphoid cortical fractures CBCT sensitivity is 100% (95% CI: 75%-100%), specificity 97% (95% CI: 83%-100%). CBCT diagnosed all 24 corticals wrist fractures, corresponding to a sensitivity of 100% (95% CI: 83%-100%), specificity of 95% (95% CI: 75%-100%). Kappa agreement rate between the two radiologists was K=0.95 (95% CI: 0.85-1) for scaphoid fractures and K=0.87 (95% CI: 0.73-1) for wrist fractures. CONCLUSIONS: CBCT is superior to radiographs for diagnosing occult cortical fractures. Because of its low radiation dose, we believe that CBCT can be used in current practice as a replacement or supplement to radiographs to detect these fractures and optimize the cost-effectiveness ratio by limiting the number of needless immobilizations

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe