title: Module organization and variance in protein-protein interaction networks.
abstract: A module is a group of closely related proteins that act in concert to perform specific biological functions through protein-protein interactions (PPIs) that occur in time and space. However, the underlying module organization and variance remain unclear. In this study, we collected module templates to infer respective module families, including 58,041 homologous modules in 1,678 species, and PPI families using searches of complete genomic database. We then derived PPI evolution scores and interface evolution scores to describe the module elements, including core and ring components. Functions of core components were highly correlated with those of essential genes. In comparison with ring components, core proteins/PPIs were conserved across multiple species. Subsequently, protein/module variance of PPI networks confirmed that core components form dynamic network hubs and play key roles in various biological functions. Based on the analyses of gene essentiality, module variance, and gene co-expression, we summarize the observations of module organization and variance as follows: 1) a module consists of core and ring components; 2) core components perform major biological functions and collaborate with ring components to execute certain functions in some cases; 3) core components are more conserved and essential during organizational changes in different biological states or conditions.
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Chun-Yu
authors: CY
authors: Lin
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Tsai-Ling
authors: TL
authors: Lee
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Yi-Yuan
authors: YY
authors: Chiu
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Yi-Wei
authors: YW
authors: Lin
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Yu-Shu
authors: YS
authors: Lo
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Chih-Ta
authors: CT
authors: Lin
authors: 1] Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan [2] Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Jinn-Moon
authors: JM
authors: Yang
mesh_terms: D000465:Algorithms; D000704:Analysis of Variance; D000818:Animals; D030541:Databases, Genetic; D004023:Dictyostelium / Q000235:genetics; D005658:Fungi / Q000235:genetics; D015870:Gene Expression; D053263:Gene Regulatory Networks; D020043:Genes, Essential; D006801:Humans; D008957:Models, Genetic; D010944:Plants / Q000235:genetics; D025941:Protein Interaction Mapping