Functional characterization of hub proteins in weighted yeast protein-protein interaction networks

The centrality-lethality rule reveals that topological prominence of a protein indicates its functional importance. But are all hub proteins in PPI network essential? Using P-value to weight PPI networks, we classified hub proteins into two types: essential hub and nonessential hub. The weighted centrality measure of weighted PPI networks showed that the weighted method can give greater support for functional characterization of hub proteins. We found that essential hubs are vital and they tend to be intra-modular hubs, while nonessential hubs are useful in maintaining the overall network connectivity and tend to be inter-modular hubs.