title: Biological process linkage networks.
abstract: BACKGROUND
  The traditional approach to studying complex biological networks is based on the identification of interactions between internal components of signaling or metabolic pathways. By comparison, little is known about interactions between higher order biological systems, such as biological pathways and processes. We propose a methodology for gleaning patterns of interactions between biological processes by analyzing protein-protein interactions, transcriptional co-expression and genetic interactions. At the heart of the methodology are the concept of Linked Processes and the resultant network of biological processes, the Process Linkage Network (PLN).
  
  
  RESULTS
  We construct, catalogue, and analyze different types of PLNs derived from different data sources and different species. When applied to the Gene Ontology, many of the resulting links connect processes that are distant from each other in the hierarchy, even though the connection makes eminent sense biologically. Some others, however, carry an element of surprise and may reflect mechanisms that are unique to the organism under investigation. In this aspect our method complements the link structure between processes inherent in the Gene Ontology, which by its very nature is species-independent. As a practical application of the linkage of processes we demonstrate that it can be effectively used in protein function prediction, having the power to increase both the coverage and the accuracy of predictions, when carefully integrated into prediction methods.
  
  
  CONCLUSIONS
  Our approach constitutes a promising new direction towards understanding the higher levels of organization of the cell as a system which should help current efforts to re-engineer ontologies and improve our ability to predict which proteins are involved in specific biological processes.
authors.affiliation: Department of Computer Science, Ben-Gurion University, Beer Sheva, Israel. dotna@cs.bgu.ac.il
authors.forename: Dikla
authors.initials: D
authors.lastname: Dotan-Cohen
authors.forename: Stan
authors.initials: S
authors.lastname: Letovsky
authors.forename: Avraham A
authors.initials: AA
authors.lastname: Melkman
authors.forename: Simon
authors.initials: S
authors.lastname: Kasif
mesh_terms: D000465:Algorithms; D001686:Biological Phenomena; D019295:Computational Biology; D030562:Databases, Protein; D053263:Gene Regulatory Networks; D025941:Protein Interaction Mapping; D011506:Proteins / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D011506:Proteins