"Progress Towards Uncovering Each Protein’s Social Network"
Professor Steve Gygi, Harvard University, Cambridge, Massachusetts
Protein-protein interactions form a network whose structure drives cellular function and whose organization informs all biological inquiry. Using high-throughput affinity-purification mass spectrometry, we identify interacting partners for 2,594 human proteins in HEK293T cells. The resulting network (BioPlex) contains 23,744 interactions, 86% unknown, among 7,668 proteins. BioPlex accurately depicts known complexes, attaining 80-100% coverage for most CORUM complexes. Network structure reveals 4 key features: 1) BioPlex subdivides into >300 communities, uniting proteins with shared function. 2) Interactions predict 2,968 associations among co-occurring Pfam domains. 3) Attributes including localization, biological process, and molecular function were determined for thousands of proteins - many uncharacterized. The network provides a framework for hypothesis generation and refinement as applied to protein function, mechanism, and activity.