Title: On the interconnection of stable protein complexes: inter-complex hubs and their conservation in Saccharomyces cerevisiae and Homo sapiens networks

Authors: Concettina Guerra

Addresses: School of Interactive Computing, College of Computing, Georgia Institute of Technology, 85 Fifth Street NW, Atlanta, GA 30308, USA

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.

Keywords: protein-protein interaction; PPI networks; stable protein complexes; inter-complex hubs; Saccharomyces cerevisiae; Homo sapiens; centrality; betweenness; evolutionary conservation; essentiality; interconnecting complexes; crossroad index; bioinformatics.

DOI: 10.1504/IJBRA.2015.073236

International Journal of Bioinformatics Research and Applications, 2015 Vol.11 No.6, pp.483 - 502

Received: 16 Dec 2014
Accepted: 13 Jun 2015
Published online: 29 Nov 2015 *

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