Giardia lamblia?s Protein-Protein Interaction Network

ZAMPONI N; MARINO BUSLJE C; TOUZ MC

Congreso; Congreso Argentino de Bioinformática y Biología Computacional. 4ta. Conferencia Internacional de la Sociedad Iberoamericana de Bioinformática (SolBio).; 2013

Background Giardia is a genus of anaerobic flagellated protozoan parasites of the phylum Diplomonada, in the supergroup "Excavata", that parasitizes the intestine of vertebrates, being one of the most common causes of human diarrheal disease worldwide. During its life cycle, Giardia alternates between the disease-causing trophozoite and the hardy dormant cyst, that contaminates water or food the infective cysts. Giardia comprises a group of true eukaryotic organisms, since they have two nuclei, a very developed endomembranous system and a complex cytoskeleton. However, this group also possess several prokaryotic features, including reduced metabolic pathways and the lack of organelles typical of more derived eukaryotes, such as mitochondria, peroxisomes, and a Golgi apparatus. An essential part in the understanding of any organism?s cellular biology is related to the description of its protein-protein interaction network (PIN). We have taken a computational approach to construct the PINs of the three known Giardia lamblia isolates (A, B, E). Results In this work, the Interolog Mapping method was used. Specifically on this approach, it assumes that if two proteins have a great sequence similarity against two proteins from a public database, and these latter ones interact, then the former ones interact as well. Using this methodology, we predicted the PINs for isolates A, B and E of Giardia lamblia. These networks comprise more than 1500 nodes, and about 30000 interactions each. On these networks, we perform topological, biological processenrichment, and metabolic pathway description and analysis. Analyzing the network with topological indexes such as degree and centrality, we detected proteins that are potentially crucial for Giardia?s encystation and survival. Conclusion We have constructed the first PIN of Giardia lamblia by using a computational approach. The topological and functional analysis of the resulting PIN enabled us to describe aspects of the biology of these organisms from a previously unexplored point of view.