Citrus psorosis virus movement protein contains an aspartic protease required for autocleavage and the formation of tubule-like structures at plasmodesmata

Plant virus cell-to-cell movement is an essential step in viral infections. This process is facilitated by specific virus-encoded movement proteins (MPs), which manipulate the cell wall channels between neighboring cells known as plasmodesmata (PD). Citrus psorosis virus (CPsV) infection in sweet orange involves the formation of tubule-like structures within PD, suggesting that CPsV belongs to "tubuleforming" viruses that encode MPs able to assemble a hollow tubule extending between cells to allow virus movement. Consistent with this hypothesis, we show that the MP of CPsV (MPCPsV) indeed forms tubule-like structures at PD upon transient expression in Nicotiana benthamiana leaves. Tubule formation by MPCPsV depends on its cleavage capacity, mediated by a specific aspartic protease motif present in its primary sequence. A single amino acid mutation in this motif abolishes MPCPsV cleavage, alters the subcellular localization of the protein, and negatively affects its activity in facilitating virus movement. The amino-terminal 34-kDa cleavage product (34KCPsV), but not the 20-kDa fragment (20KCPsV), supports virus movement. Moreover, similar to tubule-forming MPs of other viruses, MPCPsV (and also the 34KCPsV cleavage product) can homooligomerize, interact with PD-located protein 1 (PDLP1), and assemble tubule-like structures at PD by a mechanism dependent on the secretory pathway. 20KCPsV retains the protease activity and is able to cleave a cleavage-deficient MPCPsV in trans. Altogether, these results demonstrate that CPsV movement depends on the autolytic cleavage of MPCPsV by an aspartic protease activity, which removes the 20KCPsV protease and thereby releases the 34KCPsV protein for PDLP1-dependent tubule formation at PD. IMPORTANCE Infection by citrus psorosis virus (CPsV) involves a self-cleaving aspartic protease activity within the viral movement protein (MP), which results in the production of two peptides, termed 34KCPsV and 20KCPsV, that carry the MP and viral protease activities, respectively. The underlying protease motif within the MP is also found in the MPs of other members of the Aspiviridae family, suggesting that protease-mediated protein processing represents a conserved mechanism of protein expression in this virus family. The results also demonstrate that CPsV and potentially other ophioviruses move by a tubule-guided mechanism. Although several viruses from different genera were shown to use this mechanism for cell-to-cell movement, our results also demonstrate that this mechanism is controlled by posttranslational protein cleavage. Moreover, given that tubule formation and virus movement could be inhibited by a mutation in the protease motif, targeting the protease activity for inactivation could represent an important approach for ophiovirus control.Fil: Robles Luna, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Peña, Eduardo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Borniego, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Heinlein, Manfred. Université de Strasbourg; Francia. Centre National de la Recherche Scientifique; FranciaFil: Garcia, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

HETEROGENEITY EDUCATIONAL DEMANDS

Las demandas educativas cambian, fruto de las peculiaridades de cada sociedad. Entre las transformaciones experimentadas por la sociedad destaca la diversificación de la población que accede a la educación escolar. El acercamiento a éste cambio se realiza desde la innovación o la renovación educativa y lo que hoy se ha venido a denominar la sostenibilidad del cambio.Asi la sociedad lo propone como necesario para que el proyecto social que pretende cumpla sus objetivosEducational demands change, the result of the peculiarities of each company. Among the changes experienced by society highlights the diversity of the population access to schooling.    The approach to this change is made from innovation or educational reform and what today has become known as the sustainability of society cambio.Asi proposes it as necessary for the social project that aims to meet its objectives. For this reason the importance of identifying the realities now facing school

Interplay between potato virus X and RNA granules in Nicotiana benthamiana

Cytoplasmic RNA granules consist of microscopic agglomerates of mRNAs and proteins and occur when the translation is reversibly and temporally halted (stress granules, SGs) or mRNAs are targeted for decapping (processing bodies, PBs). The induction of RNA granules formation by virus infection is a common feature of mammalian cells. However, plant-virus systems still remain poorly characterized. In this work, the SG marker AtUBP1b was expressed in Nicotiana benthamiana plants to decipher how the virus infection of plant cells affects SG dynamics. We found that the hypoxia-induced SG assembly was substantially inhibited in Potato virus X (PVX)-infected cells. Furthermore, we determined that the expression of PVX movement protein TGBp1 by itself, mimics the inhibitory effect of PVX on SG formation under hypoxia. Importantly, overexpression of AtUBP1b showed inhibition of the PVX spreading, whereas the overexpression of the dominant negative AtUBP1brrm enhanced PVX spreding, indicating that AtUBP1b negatively affects PVX infection. Notably, PVX infection did not inhibit the formation of processing bodies (PBs), indicating PVX has distinct effects depending on the type of RNA granule. Our results suggest that SG inhibition could be part of the virus strategy to infect the plant.Fil: Robles Luna, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Furman, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Barbarich, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Carlotto, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Attorresi, Alejandra Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biomedicina de Buenos Aires - Instituto Partner de la Sociedad Max Planck; ArgentinaFil: Garcia, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Kobayashi, Ken. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

The Role of Copper in the Hydrogenation of Furfural and Levulinic Acid

Currently, there is a great interest in the development of sustainable and green technologies for production of biofuels and chemicals. In this sense, much attention is being paid to lignocellulosic biomass as feedstock, as alternative to fossil-based resources, inasmuch as its fractions can be transformed into value-added chemicals. Two important platform molecules derived from lignocellulosic sugars are furfural and levulinic acid, which can be transformed into a large spectrum of chemicals, by hydrogenation, oxidation, or condensation, with applications as solvents, agrochemicals, fragrances, pharmaceuticals, among others. However, in many cases, noble metal-based catalysts, scarce and expensive, are used. Therefore, an important effort is performed to search the most abundant, readily available, and cheap transition-metal-based catalysts. Among these, copper-based catalysts have been proposed, and the present review deals with the hydrogenation of furfural and levulinic acid, with Cu-based catalysts, into several relevant chemicals: furfuryl alcohol, 2-methylfuran, and cyclopentanone from FUR, and γ-valerolactone and 2-methyltetrahydrofuran from LA. Special emphasis has been placed on catalytic processes used (gas- and liquid-phase, catalytic transfer hydrogenation), under heterogeneous catalysis. Moreover, the effect of addition of other metal to Cu-based catalysts has been considered, as well as the issue related to catalyst stability in reusing studies.Partial funding for open access charge: Universidad de Málag

PLANEACIÓN DIDÁCTICA GENERAL DE LA ASIGNATURA: LÓGICA

GUÍA DIDÁCTICA / PLANEACIÓN DIDÁCTICA (NMS

The effects of remineralization via fluoride versus Low-Level Laser IR810 and fluoride agents on the mineralization and microhardness of bovine dental

Abstract: The objective of this study was to assess the mineralization and microhardness of bovine dental enamel surfaces treated with fluoride, tri-calcium phosphate, and infrared (IR) 810 laser irradiation. The study used 210 bovine incisors, which were divided into six groups (n = 35 in each): Group A: Untreated (control), Group B: Fluoride (Durapath-Colgate), Group C: Fluoride+Tri-calcium phosphate (Clin-Pro White-3 M), Group D: Laser IR 810 (Quantum), Group E: Fluoride+laser, and Group F: Fluoride+tri-calcium phosphate+laser). Mineralization was measured via UV-Vis spectroscopy for phosphorus and via atomic absorption spectroscopy for calcium upon demineralization and remineralization with proven agents. Microhardness (SMH) was measured after enamel remineralization. Mineral loss data showed differences between the groups before and after the mineralizing agents were placed (p < 0.05). Fluoride presented the highest remineralization tendency for both calcium and phosphate, with a Vickers microhardness of 329.8 HV0.1/11 (p < 0.05). It was observed that, if remineralization solution contained fewer minerals, the microhardness surface values were higher (r = −0.268 and −0.208; p < 0.05). This study shows that fluoride has a remineralizing effect compared with calcium triphosphate and laser IR810. This in vitro study imitated the application of different remineralizing agents and showed which one was the most efficient for treating non-cavitated injuries. This can prevent the progression of lesions in patients with white spot lesions

Pruebas in vitro de andamios 3D de biomaterial compuesto, formado por hiroxiapatita y ácido poliláctico

El interés de este estudio, es el desarrollo del ensayo biomimético de un andamio de material compuesto, con base en HAP-PLA conformado por impresión 3D, inmerso en un fluido corporal simulado (FCS), como indicador de su bioactividad, en función del tiempo. El FCS se preparó para someter a la muestra, al proceso biomimético diferencial. El seguimiento de los experimentos, se realizó, por el análisis del FCS residual, con espectroscopía FTIR y, el análisis textural superficial, por MEB. Los resultados, del FCS, después de 48 y 72 h, indicaron la descomposición del PLA al ácido láctico; a tiempos mayores, no hubo cambios significativos. Con la degradación superficial del andamio, por la formación de poros y porosidad. La prueba biomiméticas es indicativa de la bioactividad del andamio de HAP-PLA; su comportamiento resultó satisfactorio, el FCS, emuló el fluido del cuerpo, necesario para la incorporación de la HAP, con la degradación polimérica.The aim of this study is to develop a biomimetic method for a scaffold ofbiomaterial based on HAP-PLA formed by 3D printing, immersed in a simulated body fluid (SBF), as an indicator of its bioactivity, in function of time. The method was the differential biomimetic with preparing the SBF in where the sample was immersed. The FTIR spectroscopy was used to analyze the residual SBF and SEM, the superficial textural of scaffold was analyzed. The SBF results indicated the PLA decomposition to lactic acid, after 48 and 72 h; at longer times, the changes were insignificant. And the formation of pares and porosity showed the superficial degradation of the scaffolding. The biomimetic test is indicator of the bioactivity of the HAP-PLA scaffold; with a satisfactory behavior, because the SBF, emulate the body fluid needed to incorporate the hap, with polymer degradation

Estudio de las condiciones para la síntesis de la hidroxiapatita y el β-fosfato tricálcico

El propósito de este estudio es encontrar las condiciones de síntesis reproducibles para obtener una HAP y un β-TCP, de fase única, con una pureza >99% y, de tamaño de partícula entre 20 y 60 nm; debido a la falta de congruencia en los procedimientos. El estudio se desarrolló, por el método de co-precipitación, con el control y la variación de las condiciones de reacción, de añejamiento y de cristalización. El seguimiento de los resultados se hizo por IR-TF y DRX. Los resultados para el β-TCP, mostraron la fase bifásica formada por β-TCP, con una cantidad mínima de HAP. En el caso de la HAP se estableció una metodología reproducible, para una pureza mayor al 99%, un tamaño 31.86 nm; similar a 35.54 nm a una, de tipo bovino. La HAP funcional sintetizada se usará en el diseño de andamios bioactivos mediante la impresión 3D para regeneración del tejido óseo.The aim of this study is obtain reproducible synthesis conditions for the HAP and the β-TCP, as unique phase, with a purity >99% and particle size of 20-60 nm; due to incongruence in procedures. The study was performed with the co-precipitation method, varying the conditions of reaction, aging and crystallization. The XRD and FT-IR were used to follow the procedures. The synthesis results of β-TCP showed a biphasic phase formed with β-TCP and a minimum amount of HAP. In the case of the HAP, a reproducible methodology was stablished, with a purity >99% and size of 31.86 nm, similar to one bovine of 35.54 nm. The HAP functional synthesized will be used in the design of bioactive scaffolds by printing 3D for bone tissue regeneration

Alpha-mannosidosis caused by toxic plants in ruminants of Argentina

It is well known that several of the swainsonine-containing plant species found widespread around the world have a negative economic impact in each country. In Argentina, most of the information on the poisonous plant species that produce α-mannosidosis is published in Spanish and thus not available to most English speaking researchers interested in toxic plants. Therefore, the aim of this review is to summarize the information about swainsonine-containing plants in Argentina, which are extensively distributed throughout different ecoregions of the country. To date, five species from three genera have been shown to induce α-mannosidosis in livestock in Argentina: Ipomoea carnea subsp. fi stulosa, Ipomoea hieronymi subsp. calchaquina (Convolvulaceae), Astragalus garbancillo, Astragalus pehuenches (Fabaceae), and Sida rodrigoi (Malvaceae). These species contain the indolizidine alkaloid swainsonine, which inhibits the lysosomal enzyme α-mannosidase and consequently affects glycoprotein metabolism, resulting in partially metabolized sugars. The prolonged consumption of these poisonous plants produces progressive weight loss and clinical signs related to a nervous disorder, characterized by tremors of head and neck, abnormalities of gait, difficulty in standing, ataxia and wide-based stance. Histological lesions are mainly characterized by vacuolation of different cells, especially neurons of the central nervous system. The main animal model used to study α-mannosidosis is the guinea pig because, when experimentally poisoned, it exhibits many of the characteristics of naturally intoxicated livestock.Estación Experimental Agropecuaria BarilocheFil: Cholich, Luciana Andrea. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Cholich, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martinez, Agustin. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Grupo de Sanidad Animal; ArgentinaFil: Micheloud, Juan Francisco. Universidad Católica de Salta. Facultad de Ciencias Veterinarias y Agronomía; ArgentinaFil: Micheloud, Juan Francisco. Instituto Nacional de Tecnologia Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido. Área de Sanidad Animal; ArgentinaFil: Pistán, Maria Elena. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Garcia, Enrique Nicolas. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Robles, Carlos Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Grupo de Sanidad Animal; ArgentinaFil: Ortega, Hugo Hector. Universidad Nacional del Litoral. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Ortega, Hugo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gimeno, Eduardo Juan. Universidad Nacional de la Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Gimeno, Eduardo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Short and long-term experiments on the effect of sulphide on microalgae cultivation in tertiary sewage treatment

[EN] Microalgae cultivation appears to be a promising technology for treating nutrient-rich effluents from anaerobic membrane bioreactors, as microalgae are able to consume nutrients from sewage without an organic carbon source, although the sulphide formed during the anaerobic treatment does have negative effects on microalgae growth. Short and long-term experiments were carried out on the effects of sulphide on a mixed microalgae culture. The short-term experiments showed that the oxygen production rate (OPR) dropped as sulphide concentration increased: a concentration of 5 mg S L¿1 reduced OPR by 43%, while a concentration of 50 mg S L¿1 came close to completely inhibiting microalgae growth. The long-term experiments revealed that the presence of sulphide in the influent had inhibitory effects at sulphide concentrations above 20 mg S L¿1 in the culture, but not at concentrations below 5 mg S L¿1. These conditions favoured Chlorella growth over that of Scenedesmus.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, CTM2011-28595-C02-01 and CTM2011-28595-C02-02) jointly with the European Regional Development Fund (ERDF), both of which are gratefully acknowledged. It was also supported by the Spanish Ministry of Education, Culture and Sport via a pre doctoral FPU fellowship to author J. Gonzalez-Camejo (FPU14/05082) and by the Spanish Ministry of Economy and Competitiveness via a pre doctoral FPI fellowship to author R. Serna-Garcia (project CTM2014-54980-C2-1-R)Gonzalez-Camejo, J.; Serna-Garcia, R.; Viruela Navarro, A.; Paches Giner, MAV.; Durán Pinzón, F.; Robles Martínez, Á.; Ruano García, MV.... (2017). Short and long-term experiments on the effect of sulphide on microalgae cultivation in tertiary sewage treatment. Bioresource Technology. 244:15-22. https://doi.org/10.1016/j.biortech.2017.07.126S152224