Achievement

IGERT trainee Eric Franzosa in Wang, Franzosa, Zhang, and Xia (2010). Protein evolution in yeast transcription factor subnetworks. Nucleic Acids Research: 38, 5959-69. When averaged over the full yeast protein-protein interaction and transcriptional regulatory networks, protein hubs with many interaction partners or regulators tend to evolve significantly more slowly than non-hubs. However, analysis of the subnetworks of yeast transcription factors (TFs) reveals that TF hubs do not tend to evolve significantly more slowly than TF non-hubs. More importantly, the correlations between evolutionary rate and degrees for TFs are significantly more positive than those for generic proteins within the same global protein-protein interaction and transcriptional regulatory networks. Compared to generic protein hubs, TF hubs operate at a higher level in the hierarchical structure of cellular networks, and hence experience additional evolutionary forces.