EXACT2: the semantics of biomedical protocols

© 2014 Soldatova et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This article has been made available through the Brunel Open Access Publishing Fund.Background: The reliability and reproducibility of experimental procedures is a cornerstone of scientific practice. There is a pressing technological need for the better representation of biomedical protocols to enable other agents (human or machine) to better reproduce results. A framework that ensures that all information required for the replication of experimental protocols is essential to achieve reproducibility. Methods: We have developed the ontology EXACT2 (EXperimental ACTions) that is designed to capture the full semantics of biomedical protocols required for their reproducibility. To construct EXACT2 we manually inspected hundreds of published and commercial biomedical protocols from several areas of biomedicine. After establishing a clear pattern for extracting the required information we utilized text-mining tools to translate the protocols into a machine amenable format. We have verified the utility of EXACT2 through the successful processing of previously ‘unseen’ (not used for the construction of EXACT2) protocols. Results: The paper reports on a fundamentally new version EXACT2 that supports the semantically-defined representation of biomedical protocols. The ability of EXACT2 to capture the semantics of biomedical procedures was verified through a text mining use case. In this EXACT2 is used as a reference model for text mining tools to identify terms pertinent to experimental actions, and their properties, in biomedical protocols expressed in natural language. An EXACT2-based framework for the translation of biomedical protocols to a machine amenable format is proposed. Conclusions: The EXACT2 ontology is sufficient to record, in a machine processable form, the essential information about biomedical protocols. EXACT2 defines explicit semantics of experimental actions, and can be used by various computer applications. It can serve as a reference model for for the translation of biomedical protocols in natural language into a semantically-defined format.This work has been partially funded by the Brunel University BRIEF award and a grant from Occams Resources

Mosaic Evolution of Molecular Pathways for Sex Pheromone Communication in a Butterfly

peer reviewe

Caractérisation d’aptamères peptidiques suppresseurs et de leur(s) cible(s) dans le contexte de la mort cellulaire Bax-dependante

Les aptamères peptidiques sont des protéines combinatoires capables de moduler spécifiquement une fonction de leur cible. Une sélection fonctionelle d’aptamères peptidiques capables d’inhiber la mort cellulaire Bax-dependante chez la levure et en cellules mammaifères a été effectuée. Deux aptamères peptidiques ont été sélectionnés (Apta-32 et Apta-34). L’objectif de ce travail de thèse a été de caractériser ces deux aptamères peptidiques et leur(s) cible(s) dans le contexte de la mort cellulaire Bax-dependante. La première partie est l’étude de l’Apta-34 qui cible une protéine (C34) contenant un domaine de mort et ayant des fonctions pro-apoptotiques. Nous avons montré que lors de l’induction de l’apoptose, C34 est transloquée du noyau (sa localisation principale) au cytoplasme. Dans les mêmes conditions, Apta-34 co-localise avec C34 dans le noyau, empêchant, ou du moins retardant, sa sortie du noyau. De plus nous avons identifié le site de liaison d’Apta-34 sur C34, qui est localisé dans les 215 amino acides en N-terminale de la protéine, une région qui contient un site prédictif d’export nucléaire. Finalement, nous avons montré que la délétion de l’homologue de C34 protège contre la mort induite par hBax en levure. La seconde partie est l’étude d’Apta-32 qui cible deux paralogues (C32a et b) d’une famille de protéine impliquée dans le traffic membranaire dans les voies de l’endocytose. Nous avons montré qu’Apta-32 se lie à un domaine fonctionnel de C32. Des études in silico de docking ont permis d’identifier trois sites distincts de liaison d’Apta-32 sur ce domaine. Le site dominant est composé d’acides aminés qui partagent des propriétés physico-chimiques communes entre les différents interacteurs d’Apta-32 (C32a, C32b et l’homologue levure) mais pas avec des homologues qui ne lient pas Apta-32. De plus un screening double hybride d’une banque de cDNA levure a permis d’identifier des cibles mevure d’Apta-32. Finalement, des études préliminaires chez l’embryons de drosophile, permettent de suggérer que l’expression d’Apta-32 peut entraîner un défaut de la phagocytose. Cette étude a permis d’identifier des régulateurs de la mort cellulaires impliqués dans deux processus cellulaires distincts.Peptide aptamers are small combinatorial proteins able to specifically modulate a function of their target. A functional selection of peptide aptamers able to inhibit Bax-dependent cell death in yeast and mammalian systems has been performed. Two peptide aptamers have been selected (Apta-32 and Apta-34). The aim of this thesis project was to characterize those two inhibitory peptide aptamers and their targets in order to understand their function in the Bax-dependent cell death. The first part focuses on Apta-34 that targets a Death Domain-containing protein (T34) that has pro-apoptotic functions. We showed that during the induction of apoptosis T34 translocates from nucleus (its major localization site) to the cytoplasm. In the same conditions, Apta-34 co-localizes with T34 in the nucleus, inhibiting or at least delaying its exit from the nucleus. Moreover we identified that Apta-34 binds to the well conserved 215 N-terminal amino acids of T34 that contains a putative Nuclear Export Signal. Finally we showed that the deletion of its homologue prevents hBax-induced cell death in yeast. The second part focuses on Apta-32 that targets two paralogues (T32a and b) of a family of proteins involved in the endocytotic membrane trafficking. We showed that Apta-32 is binding to a functional domain of T32. By in silico docking studies we identified 3 distinct binding sites of Apta-32 on this domain. The dominant binding site is composed by amino acid that share physico-chemical properties between binders of Apta-32 (T32a, T32b and a yeast homologue) but not with homologues that do not bind Apta-32. Moreover we identified yeast targets of Apta-32 by yeast two hybrid yeast cDNA library screening. Finally preliminary observations on drosophila embryos expressing Apta-32 suggest that Apta-32 expression could lead to a defect on phagocytosis. This study leads to the identification of regulators of the cell death acting on two distinct pathways

Caractérisation d’aptamères peptidiques suppresseurs et de leur(s) cible(s) dans le contexte de la mort cellulaire Bax-dependante

Les aptamères peptidiques sont des protéines combinatoires capables de moduler spécifiquement une fonction de leur cible. Une sélection fonctionelle d’aptamères peptidiques capables d’inhiber la mort cellulaire Bax-dependante chez la levure et en cellules mammaifères a été effectuée. Deux aptamères peptidiques ont été sélectionnés (Apta-32 et Apta-34). L’objectif de ce travail de thèse a été de caractériser ces deux aptamères peptidiques et leur(s) cible(s) dans le contexte de la mort cellulaire Bax-dependante. La première partie est l’étude de l’Apta-34 qui cible une protéine (C34) contenant un domaine de mort et ayant des fonctions pro-apoptotiques. Nous avons montré que lors de l’induction de l’apoptose, C34 est transloquée du noyau (sa localisation principale) au cytoplasme. Dans les mêmes conditions, Apta-34 co-localise avec C34 dans le noyau, empêchant, ou du moins retardant, sa sortie du noyau. De plus nous avons identifié le site de liaison d’Apta-34 sur C34, qui est localisé dans les 215 amino acides en N-terminale de la protéine, une région qui contient un site prédictif d’export nucléaire. Finalement, nous avons montré que la délétion de l’homologue de C34 protège contre la mort induite par hBax en levure. La seconde partie est l’étude d’Apta-32 qui cible deux paralogues (C32a et b) d’une famille de protéine impliquée dans le traffic membranaire dans les voies de l’endocytose. Nous avons montré qu’Apta-32 se lie à un domaine fonctionnel de C32. Des études in silico de docking ont permis d’identifier trois sites distincts de liaison d’Apta-32 sur ce domaine. Le site dominant est composé d’acides aminés qui partagent des propriétés physico-chimiques communes entre les différents interacteurs d’Apta-32 (C32a, C32b et l’homologue levure) mais pas avec des homologues qui ne lient pas Apta-32. De plus un screening double hybride d’une banque de cDNA levure a permis d’identifier des cibles mevure d’Apta-32. Finalement, des études préliminaires chez l’embryons de drosophile, permettent de suggérer que l’expression d’Apta-32 peut entraîner un défaut de la phagocytose. Cette étude a permis d’identifier des régulateurs de la mort cellulaires impliqués dans deux processus cellulaires distincts.Peptide aptamers are small combinatorial proteins able to specifically modulate a function of their target. A functional selection of peptide aptamers able to inhibit Bax-dependent cell death in yeast and mammalian systems has been performed. Two peptide aptamers have been selected (Apta-32 and Apta-34). The aim of this thesis project was to characterize those two inhibitory peptide aptamers and their targets in order to understand their function in the Bax-dependent cell death. The first part focuses on Apta-34 that targets a Death Domain-containing protein (T34) that has pro-apoptotic functions. We showed that during the induction of apoptosis T34 translocates from nucleus (its major localization site) to the cytoplasm. In the same conditions, Apta-34 co-localizes with T34 in the nucleus, inhibiting or at least delaying its exit from the nucleus. Moreover we identified that Apta-34 binds to the well conserved 215 N-terminal amino acids of T34 that contains a putative Nuclear Export Signal. Finally we showed that the deletion of its homologue prevents hBax-induced cell death in yeast. The second part focuses on Apta-32 that targets two paralogues (T32a and b) of a family of proteins involved in the endocytotic membrane trafficking. We showed that Apta-32 is binding to a functional domain of T32. By in silico docking studies we identified 3 distinct binding sites of Apta-32 on this domain. The dominant binding site is composed by amino acid that share physico-chemical properties between binders of Apta-32 (T32a, T32b and a yeast homologue) but not with homologues that do not bind Apta-32. Moreover we identified yeast targets of Apta-32 by yeast two hybrid yeast cDNA library screening. Finally preliminary observations on drosophila embryos expressing Apta-32 suggest that Apta-32 expression could lead to a defect on phagocytosis. This study leads to the identification of regulators of the cell death acting on two distinct pathways

Relative expression profile of <i>FAR2</i> gene.

<div><p>Effect of normalization with (A) <i>RpS8</i>, (B) <i>Rps8</i> and <i>RpS18</i>, and(C) <i>ACT3</i> on the expression of <i>FAR 2</i> gene. Data are means of three biological replicates ± SE. Significant difference in the transcript abundance of male wing tissue containing the androconia (“Wings M And”) as compared with female wing tissues (“Wings F”) was observed in (A) and (B) (* indicates p-value < 0.01).</p> <p>Pupae M = pupae male; Pupae F = pupae female; Wings M And = adult wings male androconia; Wings M Cont = Adult wings male control; Wings F = adult wings female; Brain M = Brain male; Brain F = Brain female; Antennae M,F = antennae male and female.</p></div

List of genes with associated functions selected for the study.

<p>List of genes with associated functions selected for the study.</p

Expression range of Ct values of 12 candidate reference genes.

<p>(A) total tissues, n = 8 sample points (B) control tissues, n = 8 sample points and (C) food stressed tissues, n = 16 sample points. Black line across each box represents the median. Box limits indicate the 25^th and 75^th percentiles as determined by R software; whiskers extend 1.5 times the interquartile range from the 25^th and 75^th percentiles, outliers are represented by dots. Ct values and genes are shown on Y- and X-axis, respectively.</p

Measures of expression stability (M value).

<p>geNorm analysis and ranking of 12 candidate reference genes in (A) all tissues (B) control tissues and (C) food stressed tissues. Suitable reference genes are assigned M values below 0.5 (dotted line).</p

Expression stability of candidate reference genes ranked by NormFinder in different tissue sets.

<p>Expression stability of candidate reference genes ranked by NormFinder in different tissue sets.</p

Consensus ranking of candidate reference genes.

<p>*The ranking has been calculated by averaging the ranks obtained by geNorm and NormFinder.</p><p>Consensus ranking of candidate reference genes.</p