Dr. Chen Zeng
Department of Physics
George Washington University
Washington, DC

Monday, March 8, 2010
3:00 pm (CT)
3269 Beckman Institute

Abstract

A central challenge in systems biology today is to understand the network of interactions among biomolecules and, especially, the design principles underlying such networks. Recent analysis of known networks has identified small motifs that occur abundantly, suggesting that larger networks might be constructed in the manner of electronic circuits by assembling groups of these smaller modules. In this talk, I will provide some evidence to the contrary. Using a novel process-based approach to analyzing such networks, we show for two cell-cycle networks that each of these networks contains a giant backbone motif spanning all the network nodes that provides the main functional response. The backbone is in fact the smallest network capable of providing the desired functionality. Furthermore, the remaining edges in the network form smaller motifs whose role is to confer stability properties rather than provide function. The process- based approach used in the above analysis has additional benefits: it is scalable, analytic (resulting in a single analyzable expression that describes the behavior) and computationally efficient (all possible minimal networks for a biological process can be identified and enumerated quickly). Furthermore, when compared with random processes, biological ones appear to be rather unique.

2:30 pm: Coffee hour Theoretical and Computational Biophysics Group area, 3rd Floor Beckman