title: On the interconnection of stable protein complexes: inter-complex hubs and their conservation in Saccharomyces cerevisiae and Homo sapiens networks.
abstract: Protein complexes are key molecular entities that perform a variety of essential cellular functions. The connectivity of proteins within a complex has been widely investigated with both experimental and computational techniques. We developed a computational approach to identify and characterise proteins that play a role in interconnecting complexes. We computed a measure of inter-complex centrality, the crossroad index, based on disjoint paths connecting proteins in distinct complexes and identified inter-complex hubs as proteins with a high value of the crossroad index. We applied the approach to a set of stable complexes in Saccharomyces cerevisiae and in Homo sapiens. Just as done for hubs, we evaluated the topological and biological properties of inter-complex hubs addressing the following questions. Do inter-complex hubs tend to be evolutionary conserved? What is the relation between crossroad index and essentiality? We found a good correlation between inter-complex hubs and both evolutionary conservation and essentiality.
authors.affiliation: 1 School of Interactive Computing, College of Computing, Georgia Institute of Technology, 85 Fifth Street NW, Atlanta, GA 30308, USA.
authors.forename: Concettina
authors.initials: C
authors.lastname: Guerra
keywords: Homo sapiens; PPI networks; Saccharomyces cerevisiae; betweenness; bioinformatics; centrality; crossroad index; essentiality; evolutionary conservation; inter-complex hubs; interconnecting complexes; protein-protein interaction; stable protein complexes