The annotation of the Asparagine N-linked Glycosylation pathway in the Reactome Databas

Institute of Evolutionary Biology, Carrer Doctor Aiguader 88, Barcelona, Catalonia, Spain.
Glycobiology (Impact Factor: 3.15). 10/2011; 21(11):1395-400. DOI: 10.1093/glycob/cwq215
Source: PubMed


Asparagine N-linked glycosylation is one of the most important forms of protein post-translational modification in eukaryotes
and is one of the first metabolic pathways described at a biochemical level. Here, we report a new annotation of this pathway
for the Human species, published after passing a peer-review process in Reactome. The new annotation presented here offers
a high level of detail and provides references and descriptions for each reaction, along with integration with GeneOntology
and other databases. The open-source approach of Reactome toward annotation encourages feedback from its users, making it
easier to keep the annotation of this pathway updated with future knowledge. Reactome's web interface allows easy navigation
between steps involved in the pathway to compare it with other pathways and resources in other scientific databases and to
export it to BioPax and SBML formats, making it accessible for computational studies. This new entry in Reactome expands and
complements the annotations already published in databases for biological pathways and provides a common reference to researchers
interested in studying this important pathway in the human species. Finally, we discuss the status of the annotation of this
pathway and point out which steps are worth further investigation or need better experimental validation.

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Available from: Jaume Bertranpetit
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    • "For this, all known interactions involved in the system were carefully curated from research literature to arrive at a network of high confidence (Additional file 1: Table S2). This is important, as there tend to be inaccuracies and omissions in many pathway representations found in public databases, which may introduce too many errors for non-interactome-scale analyses [31,32]. "
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    ABSTRACT: Background Visual perception is initiated in the photoreceptor cells of the retina via the phototransduction system. This system has shown marked evolution during mammalian divergence in such complex attributes as activation time and recovery time. We have performed a molecular evolutionary analysis of proteins involved in mammalian phototransduction in order to unravel how the action of natural selection has been distributed throughout the system to evolve such traits. Results We found selective pressures to be non-randomly distributed according to both a simple protein classification scheme and a protein-interaction network representation of the signaling pathway. Proteins which are topologically central in the signaling pathway, such as the G proteins, as well as retinoid cycle chaperones and proteins involved in photoreceptor cell-type determination, were found to be more constrained in their evolution. Proteins peripheral to the pathway, such as ion channels and exchangers, as well as the retinoid cycle enzymes, have experienced a relaxation of selective pressures. Furthermore, signals of positive selection were detected in two genes: the short-wave (blue) opsin (OPN1SW) in hominids and the rod-specific Na+/ Ca2+, K+ ion exchanger (SLC24A1) in rodents. Conclusions The functions of the proteins involved in phototransduction and the topology of the interactions between them have imposed non-random constraints on their evolution. Thus, in shaping or conserving system-level phototransduction traits, natural selection has targeted the underlying proteins in a concerted manner.
    Full-text · Article · Feb 2013 · BMC Evolutionary Biology
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    • "In a previous work, we annotated the pathway of Asparagine N-Glycosylation in the Reactome Database [41]. From the genes annotated in Reactome, we initially selected a list of 62 genes, corresponding to the genes that, in the literature, are considered associated to this pathway. "
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    ABSTRACT: Asparagine N-Glycosylation is one of the most important forms of protein post-translational modification in eukaryotes. This metabolic pathway can be subdivided into two parts: an upstream sub-pathway required for achieving proper folding for most of the proteins synthesized in the secretory pathway, and a downstream sub-pathway required to give variability to trans-membrane proteins, and involved in adaptation to the environment and innate immunity. Here we analyze the nucleotide variability of the genes of this pathway in human populations, identifying which genes show greater population differentiation and which genes show signatures of recent positive selection. We also compare how these signals are distributed between the upstream and the downstream parts of the pathway, with the aim of exploring how forces of population differentiation and positive selection vary among genes involved in the same metabolic pathway but subject to different functional constraints. Our results show that genes in the downstream part of the pathway are more likely to show a signature of population differentiation, while events of positive selection are equally distributed among the two parts of the pathway. Moreover, events of positive selection are frequent on genes that are known to be at bifurcation points, and that are identified as being in key position by a network-level analysis such as MGAT3 and GCS1. These findings indicate that the upstream part of the Asparagine N-Glycosylation pathway has lower diversity among populations, while the downstream part is freer to tolerate diversity among populations. Moreover, the distribution of signatures of population differentiation and positive selection can change between parts of a pathway, especially between parts that are exposed to different functional constraints. Our results support the hypothesis that genes involved in constitutive processes can be expected to show lower population differentiation, while genes involved in traits related to the environment should show higher variability. Taken together, this work broadens our knowledge on how events of population differentiation and of positive selection are distributed among different parts of a metabolic pathway.
    Full-text · Article · Jun 2012 · BMC Evolutionary Biology
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    • "Pathways can contain reactions, pathways or both. Pathways in turn have been grouped into approximately 160 canonical pathways each of which corresponds to a substantial, tightly connected domain of human biology such as carbohydrate metabolism [18], solute transport regulatory pathways, GPCR signal transduction [19], cellcycle regulation and innate immunity [20]. "
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    ABSTRACT: Reactome ( is an open-source, expert-authored, peer-reviewed, manually curated database of reactions, pathways and biological processes. We provide an intuitive web-based user interface to pathway knowledge and a suite of data analysis tools. The Pathway Browser is a Systems Biology Graphical Notation-like visualization system that supports manual navigation of pathways by zooming, scrolling and event highlighting, and that exploits PSI Common Query Interface web services to overlay pathways with molecular interaction data from the Reactome Functional Interaction Network and interaction databases such as IntAct, ChEMBL and BioGRID. Pathway and expression analysis tools employ web services to provide ID mapping, pathway assignment and over-representation analysis of user-supplied data sets. By applying Ensembl Compara to curated human proteins and reactions, Reactome generates pathway inferences for 20 other species. The Species Comparison tool provides a summary of results for each of these species as a table showing numbers of orthologous proteins found by pathway from which users can navigate to inferred details for specific proteins and reactions. Reactome's diverse pathway knowledge and suite of data analysis tools provide a platform for data mining, modeling and analysis of large-scale proteomics data sets. This Tutorial is part of the International Proteomics Tutorial Programme (IPTP 8).
    Preview · Article · Sep 2011 · Proteomics
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