Two RNA-binding motifs in eIF3 direct HCV IRES-dependent translation.

The initiation of protein synthesis plays an essential regulatory role in human biology. At the center of the initiation pathway, the 13-subunit eukaryotic translation initiation factor 3 (eIF3) controls access of other initiation factors and mRNA to the ribosome by unknown mechanisms. Using electron microscopy (EM), bioinformatics and biochemical experiments, we identify two highly conserved RNA-binding motifs in eIF3 that direct translation initiation from the hepatitis C virus internal ribosome entry site (HCV IRES) RNA. Mutations in the RNA-binding motif of subunit eIF3a weaken eIF3 binding to the HCV IRES and the 40S ribosomal subunit, thereby suppressing eIF2-dependent recognition of the start codon. Mutations in the eIF3c RNA-binding motif also reduce 40S ribosomal subunit binding to eIF3, and inhibit eIF5B-dependent steps downstream of start codon recognition. These results provide the first connection between the structure of the central translation initiation factor eIF3 and recognition of the HCV genomic RNA start codon, molecular interactions that likely extend to the human transcriptome

Effect of atomic substitution on the sodium manganese ferrite thermochemical cycle for hydrogen production

This work presents the effect of atomic substitution on the MnFe2O4-Na2CO3 thermochemical cycle for H-2 production. The non-oxidative decarbonation/carbonation reaction of the MnFe2O4-Na2CO3 mixture is investigated as the starting reference. Repeated cycling results in a 30% loss of reversibility due to an overall reduction of the reactive interfaces. The substitution of Na2CO3 for Li2CO3 decreases the decarbonation onset temperature by about 100 degrees C, but almost no reversibility is observed during the cycles due to the irreversible Li+ intercalation. The effect of partial Mn substitution for Ca, Ni, and Zn is presented. The 5% Zn mixture shows the best decarbonation/carbonation reversibility and is tested for H-2 production together with MnFe2O4-Na2CO3. The reference mixture produces more H-2 during the first cycle (asymptotic to 1.1 vs. 0.7 mmol/g), but its production drastically drops by two orders of magnitude upon cycling and becomes negligible after 5 cycles. By contrast, the Zn-doped mixture exhibits a stable H-2 production of 0.22 mmol/g with no decreasing trend observed from cycle 2 to cycle 5. As result, in the fifth cycle, the Zn-doped mixture produces 23 times more H-2 than MnFe2O4-Na2CO3. Thermogravimetry and X-ray diffraction confirm that doping with Zn significantly improves the regeneration of the reactants.Acknowledgment This Project is funded by the Department of Economic Devel-opment, Sustainability and Environment of the Basque Govern-ment (CICe 2019-KK-2019/00097-and H2BASQUE-KK-2021/00054) . The authors express their sincere gratitude to Cristina Luengo and Mikel Intxaurtieta for their technical support

Two RNA-binding motifs in eIF3 direct HCV IRES-dependent translation

The initiation of protein synthesis plays an essential regulatory role in human biology. At the center of the initiation pathway, the 13-subunit eukaryotic translation initiation factor 3 (eIF3) controls access of other initiation factors and mRNA to the ribosome by unknown mechanisms. Using electron microscopy (EM), bioinformatics and biochemical experiments, we identify two highly conserved RNA-binding motifs in eIF3 that direct translation initiation from the hepatitis C virus internal ribosome entry site (HCV IRES) RNA. Mutations in the RNA-binding motif of subunit eIF3a weaken eIF3 binding to the HCV IRES and the 40S ribosomal subunit, thereby suppressing eIF2-dependent recognition of the start codon. Mutations in the eIF3c RNA-binding motif also reduce 40S ribosomal subunit binding to eIF3, and inhibit eIF5B-dependent steps downstream of start codon recognition. These results provide the first connection between the structure of the central translation initiation factor eIF3 and recognition of the HCV genomic RNA start codon, molecular interactions that likely extend to the human transcriptome. © 2013 The Author(s)National Institutes of Health (NIH) [R56-AI095687 to J.H.D.C.; P50-GM102706 to J.A.D. and J.H.D.C.]; Spanish Ministry of Education through the Programa Nacional de Movilidad de Recursos Humanos del Plan Nacional de I-D+i 2008-2011 (to E.A.-P.). J.A.D. and E.N. are Howard Hughes Medical Institute Investigators. Funding for open access charge: NIH [P50-GM102706]Peer Reviewe

Undergraduates’writing profile and their metacognitive knowledge of academic tasks

Esta investigación se centra en conocer el desarrollo de la conciencia metacognitiva y el perfil escritor de los universitarios en relación con las tareas de síntesis, altamente demandadas en la Educación Superior, pero ineficazmente abordadas por muchos estudiantes. La muestra ha estado formada por 82 universitarios, divididos en dos condiciones en las que recibieron instrucción en tareas de síntesis: enseñanza explícita y modelado con pensamiento en voz alta; respondieron a los cuestionarios i) Conocimiento metacognitivo sobre tareas de síntesis y ii) Estilos escritores. Los resultados permiten concluir que el autoconocimiento de los estudiantes acerca de las síntesis no es adecuado, aunque es mejorable con modelado o enseñanza explícita, y que los estudiantes con un perfil escritor, predominantemente revisor o planificador, son los que muestran mejor desarrollo metacognitivo.La Revista Publicaciones se edita en la Facultad y cuenta con los siguientes patrocinadores: Consejería de Educación, Juventud y Deportes (Ciudad Autónoma de Melilla) Vicerrectorado de Investigación y Transferencia de la Universidad de Granada Facultad de Educación y Humanidades de Melill

Undergraduates’writing profile and their metacognitive knowledge of academic tasks

Esta investigación se centra en conocer el desarrollo de la conciencia metacognitiva y el perfil escritor de los universitarios en relación con las tareas de síntesis, altamente demandadas en la Educación Superior, pero ineficazmente abordadas por muchos estudiantes. La muestra ha estado formada por 82 universitarios, divididos en dos condiciones en las que recibieron instrucción en tareas de síntesis: enseñanza explícita y modelado con pensamiento en voz alta; respondieron a los cuestionarios i) Conocimiento metacognitivo sobre tareas de síntesis y ii) Estilos escritores. Los resultados permiten concluir que el autoconocimiento de los estudiantes acerca de las síntesis no es adecuado, aunque es mejorable con modelado o enseñanza explícita, y que los estudiantes con un perfil escritor, predominantemente revisor o planificador, son los que muestran mejor desarrollo metacognitivo.La Revista Publicaciones se edita en la Facultad y cuenta con los siguientes patrocinadores: Consejería de Educación, Juventud y Deportes (Ciudad Autónoma de Melilla) Vicerrectorado de Investigación y Transferencia de la Universidad de Granada Facultad de Educación y Humanidades de Melill

Evaluación de conductas y actitudes de búsqueda de empleo. Revisión y validación de tres escalas para la orientación profesional

One of the fundamental objectives of career guidance is to facilitate labor integration. To do this you need to have valid and reliable instruments that evaluate the job search process. It is intended to expand and improve three scales used by the Employment and Training Service of the Region of Murcia (SEF) aimed at measuring the main cognitive-behavioral elements involved in the job search process: insertion facilitator system (SFI), search behaviors employment (ICBE) and job search expectations (ECPBE). After a preliminary study, some items are removed, and new elements are added based on the literature review and expert opinion. The improved scales are subject to validation by confirmatory factor analysis on a sample of 472 people. According to the results, the new scales have adequate reliability in all their elements with a Cronbach's alpha greater than .7. They show an adequate structure and fit in the robust Satorra-Bentler measurement model χ2 (494) = 972.43 (p = .000), NFI = .9, NNFI = .92, CFI = .93 and RMSEA = .05 with a correct convergent and discriminant validity. In conclusion, the improved scales constitute a valid and reliable measure of the main variables involved in the job search and a useful tool for decision-making based on evidence about the suitability of career guidance actions aimed at unemployed people.Uno de los objetivos fundamentales de la orientación profesional es facilitar la integración laboral. Para ello, necesita contar con instrumentos válidos y fiables que evalúen el proceso de búsqueda de empleo. Se pretende ampliar y mejorar tres escalas utilizadas por el Servicio de Empleo y Formación de la Región de Murcia (SEF) dirigidas a medir los principales elementos cognitivo-conductuales implicados en el proceso de búsqueda de empleo: sistema facilitador de inserción (SFI), conductas de búsqueda de empleo (ICBE) y expectativas de búsqueda de empleo(ECPBE). Después de estudiar su fiabilidad y validez se eliminan algunos ítems y se añaden nuevos elementos basados en la revisión de la literatura y la opinión de expertos. Las escalas mejoradas se someten a validación mediante análisis factorial confirmatorio de una muestra de 472 personas. Atendiendo a los resultados, las nuevas escalas presentan una fiabilidad adecuada en todos sus elementos con un alfa de Cronbach superior a .7. Muestran una adecuada estructura y ajuste en el modelo de medida robusto Satorra-Bentler χ2 (494) = 972.43 (p= .000), NFI= .9, NNFI= .92, CFI= .93 y RMSEA= .05 con una correcta validez convergente y discriminante. Se concluye que, las escalas mejoradas constituyen una medida válida y fiable de las principales variables implicadas en la búsqueda de empleo y una herramienta útil para la toma de decisiones basadas en la evidencia sobre la idoneidad de las actuaciones de orientación profesional dirigidas a personas desempleadas

REGULATION OF MEMBRANE BAND 3 TYR-PHOSPHORYLATION BY PROTEOLYSIS OF P72 AND POSSIBLE INVOLVEMENT IN SENESCENCE PROCESS

Erythrocyte senescence is characterized by exposure of cell surface epitopes on cell membrane proteins leading to immune mediated removal of red blood cells. One mechanism for antigen formation is tyrosine phosphorylation (Tyr-P) of the transmembrane protein band 3 by Syk kinase. Our aim was to test the hypothesis that proteolytic activation of Syk kinase by conversion from 72 kDa (p72Syk) to the 36 kDa (p36Syk) isoform enhances its phosphorylating activity independently of the association of Syk kinase with the cytoskeleton. Tyr-P assay was conducted using quantification of 32P uptake into the cytoplasmic domain of band 3 after addition of p72Syk or p36Syk. Effect of prephosphorylation of erythrocyte membrane band 3 protein by p36Syk on p72Syk-mediated phosphorylation and the effect of addition of a protease inhibitor (leupeptin) on p72Syk-mediated phosphorylation were studied by autoradiographic visualization of 32P uptake. Tyr-P by Syk isoforms of membrane skeletal and soluble fractions of band 3 was visualized by immunoblotting. It was found that p36Syk had a higher band 3 tyrosine phosphorylating activity compared with p72Syk. Pre-phosphorylation with p36Syk or p72Syk increased band 3 phosphorylating activity. Protease inhibition treatment reduced p72Syk but not p36Syk band 3 tyrosine phosphorylating activity significantly. Both soluble and membrane skeletal fractions of band 3 protein were equally tyrosine phosphorylated by each Syk isoform. In conclusion, we confirmed the hypothesis that proteolytic cleavage of p72Syk is an important regulatory step for band 3 Tyr-P and its independence of the association of band 3 with the cytoskeleton

Wax worm saliva and the enzymes therein are the key to polyethylene degradation by Galleria mellonella

Plastic degradation by biological systems with re-utilization of the by-products could be a future solution to the global threat of plastic waste accumulation. Here, we report that the saliva of Galleria mellonella larvae (wax worms) is capable of oxidizing and depolymerizing polyethylene (PE), one of the most produced and sturdy polyolefin-derived plastics. This effect is achieved after a few hours’ exposure at room temperature under physiological conditions (neutral pH). The wax worm saliva can overcome the bottleneck step in PE biodegradation, namely the initial oxidation step. Within the saliva, we identify two enzymes, belonging to the phenol oxidase family, that can reproduce the same effect. To the best of our knowledge, these enzymes are the first animal enzymes with this capability, opening the way to potential solutions for plastic waste management through bio-recycling/up-cycling

Perfil escritor y conocimiento metacognitivo de las tareas académicas en los estudiantes universitarios

p. 243-270Esta investigación se centra en conocer el desarrollo de la conciencia metacognitiva y el perfil escritor de los universitarios en relación con las tareas de síntesis, altamente demandadas en la Educación Superior, pero ineficazmente abordadas por muchos estudiantes. La muestra ha estado formada por 82 universitarios, divididos en dos condiciones en las que recibieron instrucción en tareas de síntesis: enseñanza explícita y modelado con pensamiento en voz alta; respondieron a los cuestionarios i) Conocimiento metacognitivo sobre tareas de síntesis y ii) Estilos escritores. Los resultados permiten concluir que el autoconocimiento de los estudiantes acerca de las síntesis no es adecuado, aunque es mejorable con modelado o enseñanza explícita, y que los estudiantes con un perfil escritor, predominantemente revisor o planificador, son los que muestran mejor desarrollo metacognitivoN