69 research outputs found

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

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    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

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

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    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

    Preferred reporting items for studies mapping onto preference-based outcome measures: The MAPS statement

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    'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. The primary audiences for the MAPS statement are researchers reporting mapping studies, the funders of the research, and peer reviewers and editors involved in assessing mapping studies for publication. A de novo list of 29 candidate reporting items and accompanying explanations was created by a working group comprised of six health economists and one Delphi methodologist. Following a two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community, a final set of 23 items deemed essential for transparent reporting, and accompanying explanations, was developed. The items are contained in a user friendly 23 item checklist. They are presented numerically and categorised within six sections, namely: (i) title and abstract; (ii) introduction; (iii) methods; (iv) results; (v) discussion; and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document. It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by eight health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years' time. This statement was published jointly in Applied Health Economics and Health Policy, Health and Quality of Life Outcomes, International Journal of Technology Assessment in Health Care, Journal of Medical Economics, Medical Decision Making, PharmacoEconomics, and Quality of Life Research

    Results and complications of amniocentesis. Experience of two centers of Latin American fetal maternal medicine

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    Objetivo Describir las indicaciones, complicaciones y repercusiones de la amniocentesis. Materiales y métodos Estudio descriptivo, observacional y transversal de las amniocentesis efectuadas de 2009 a 2015 en dos unidades de medicina materno fetal de Bogotá, Colombia. Se evaluaron las características de las pacientes, indicación de los procedimientos y las complicaciones. Además, los hallazgos se compararon con reportes de diferentes estudios de la bibliografía internacional. Resultados Se incluyeron 748 amniocentesis. La mediana de edad de las pacientes fue de 29 años (límites 23 y 37). La indicación más común fue el estudio genético en 508 casos (67.9%). Se reportaron 89 (17.5%) casos de cromosomopatías, y de éstas la de mayor frecuencia fue la trisomía 21 en 41 pacientes (46%). La mayor parte de las complicaciones se registró en embarazos que superaron las 20 semanas. La pérdida del embarazo y la amenaza de parto pretérmino atribuibles a la amniocentesis fueron de 0.9 y 2.5%, respectivamente. Conclusión Las características de la amniocentesis permitieron conocer sus repercusiones, complicaciones, tasa de pérdida real o factores asociados, con miras a explorar los factores maternos y fe tales en embarazos únicos y múltiples en dos unidades de Medicina Materno Fetal latinoamericanas.Objective The purpose of this paper is to describe the indications, complications and results of amniocentesis performed in two fetal maternal medicine units in Bogota Colombia between 2009 and 2015. Materials and methods Cross-sectional observational descriptive study; 770 amniocentesis performed during 6 years (2009 - 2015) with evaluation of the characteristics of the patients, procedures and complications observed were evaluated. In addition, the findings were compared with reports from different studies of the world literature. Results 748 amniocentesis data were included, statistically analyzing the clinical characteristics of the patients and the results, indications and complications of the procedure. The median age was 29 years (RIQ: 23-37). The most common indication was genetic in 508 cases (67.9%). 89 (17.5%) cases of chromosomopathies were reported, with trisomy 21 being more frequently observed in 41 patients (46%). The loss of pregnancy and the threat of preterm labor attributable to amniocentesis were 0.94% and 2.54%, respectively. Conclusion The characteristics of amniocentesis allow us to know statistics of outcomes, complications, actual loss rate or associated factors, with a view to exploring both maternal and fetal factors in single and multiple pregnancies in two units of Latin American Fetal Maternal Medicine

    The Crc global regulator binds to an unpaired A-rich motif at the Pseudomonas putida alkS mRNA coding sequence and inhibits translation initiation

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    Crc is a key global translational regulator in Pseudomonads that orchestrates the hierarchy of induction of several catabolic pathways for amino acids, sugars, hydrocarbons or aromatic compounds. In the presence of amino acids, which are preferred carbon sources, Crc inhibits translation of the Pseudomonas putida alkS and benR mRNAs, which code for transcriptional regulators of genes required to assimilate alkanes (hydrocarbons) and benzoate (an aromatic compound), respectively. Crc binds to the 5′-end of these mRNAs, but the sequence and/or structure recognized, and the way in which it inhibits translation, were unknown. We have determined the secondary structure of the alkS mRNA 5′-end through its sensitivity to several ribonucleases and chemical reagents. Footprinting and band-shift assays using variant alkS mRNAs have shown that Crc specifically binds to a short unpaired A-rich sequence located adjacent to the alkS AUG start codon. This interaction is stable enough to prevent formation of the translational initiation complex. A similar Crc-binding site was localized at benR mRNA, upstream of the Shine–Dalgarno sequence. This allowed predicting binding sites at other Crc-regulated genes, deriving a consensus sequence that will help to validate new Crc targets and to discriminate between direct and indirect effects of this regulator

    Sensing and Tactile Artificial Muscles from Reactive Materials

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    Films of conducting polymers can be oxidized and reduced in a reversible way. Any intermediate oxidation state determines an electrochemical equilibrium. Chemical or physical variables acting on the film may modify the equilibrium potential, so that the film acts as a sensor of the variable. The working potential of polypyrrole/DBSA (Dodecylbenzenesulfonic acid) films, oxidized or reduced under constant currents, changes as a function of the working conditions: electrolyte concentration, temperature or mechanical stress. During oxidation, the reactive material is a sensor of the ambient, the consumed electrical energy being the sensing magnitude. Devices based on any of the electrochemical properties of conducting polymers must act simultaneously as sensors of the working conditions. Artificial muscles, as electrochemical actuators constituted by reactive materials, respond to the ambient conditions during actuation. In this way, they can be used as actuators, sensing the surrounding conditions during actuation. Actuating and sensing signals are simultaneously included by the same two connecting wires

    An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging in patients with transient ischaemic attack and minor stroke : a systematic review, meta-analysis and economic evaluation

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    Erratum issued September 2015 Erratum DOI: 10.3310/hta18270-c201509Peer reviewedPublisher PD

    An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation

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