title: Self-similarity of human protein interaction networks: a novel strategy of distinguishing proteins.
abstract: The successful determination of reliable protein interaction networks (PINs) in several species in the post-genomic era has hitherto facilitated the quest to understanding systems and structural properties of such networks. It is envisaged that a clearer understanding of their intrinsic topological properties would elucidate evolutionary and biological topography of organisms. This, in turn, may inform the understanding of diseases' aetiology. By analysing sub-networks that are induced in various layers identified by zones defined as distance from central proteins, we show that zones of human PINs display self-similarity patterns. What is observed at a global level is repeated at lower levels of inducement. Furthermore, it is observed that these levels of strength point to refinement and specialisations in these layers. This may point to the fact that various levels of representations in the self-similarity phenomenon offer a way of measuring and distinguishing the importance of proteins in the network. To consolidate our findings, we have also considered a gene co-expression network and a class of gene regulatory networks in the same framework. In all cases, the phenomenon is significantly evident. In particular, the truly unbiased regulatory networks show finer level of articulation of self-similarity.
authors.affiliation: South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, South Africa.
authors.forename: Emad
authors.initials: E
authors.lastname: Fadhal
authors.affiliation: South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, South Africa.
authors.forename: Junaid
authors.initials: J
authors.lastname: Gamieldien
authors.affiliation: Department of Mathematics and Applied Mathematics, University of the Western Cape, P/Bag X17, Bellville, South Africa.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Mwambene
mesh_terms: D019295:Computational Biology; D019143:Evolution, Molecular; D053263:Gene Regulatory Networks; D006801:Humans; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D025941:Protein Interaction Mapping; D060066:Protein Interaction Maps; D015398:Signal Transduction