THE MODULAR ORGANIZATION OF PROTEINPROTEIN

ZAMPONI N; PEROTTI J; MIRAS S; FELIZIANI C; TAMARIT F; TOUZ MC

Congreso; SAIB; 2011

Network theory provides a framework to analyze, from a topological point of view, large amounts of data regarding molecular interactions and provide an integrated view of cellular function and evolution. In the past decades, complex network approaches to cell and molecular biology have been crucial to reveal the underlying architecture of organismal complexity. Among all of the topological properties that can be extracted, modularity (the tendency of elements or links to form more connected subsets) is considered to be one of the main organizing principles in biological networks. It has been suggested, for example, that the modularity of bacterial metabolic networks had experimented a reduction during evolution. It has been also pointed out that modularity is reduced in simbiont bacteria, but the opposite is true for obligate mammalian pathogens. In addition, the diameter of metabolic networks of parasitic eukaryotes tends to be similar to those of free-living eukaryotes, suggesting that network integrity had been a structural constraint during evolution. In this work we compare protein-protein interaction networks of unicellular eukaryotes extracted from STRING database, by calculating two different modularities. At first glance, parasitic/early divergent unicellular organisms tend to have high modularity values than non-parasitic/more derived ones.