"Biological Sciences & Bioengineering Seminar" FEB. 23, 2011-FENS 2072

Orkun Soyer, University of Exeter
13:40, February 23, 2011
FENS 2072

The emerging field of Systems Biology aims to understand biological phenomena by
concentrating on systems‐level behaviours rather than individual parts and by combining
experiments with mathematical and engineering approaches. Within this framework, an
important goal is to decipher the function and structure of cellular protein interaction networks
such as genetic, metabolic and signalling networks. High‐throughput experiments in recent
years unrevealed unexpected features of these networks including robustness and modularity.
In this talk, I will introduce host‐parasite interaction as one possible source of observed
robustness and redundancy in biological networks. Using evolutionary computer simulations
and generic mathematical models of biological networks, I will show how redundancy‐based
robustness can arise in host networks that are under parasite interference. I will then discuss a
real case from Arabidopsis thaliana, where we performed a system level analysis of the
jasmonic acid network, which is hijacked by the plant pathogen Pseudomonas syringae and
which contains a very high level of redundancy. In particular, we find that the JA networks acts
as a genetic switch and that the response dynamics of this systems can be tuned both
qualitatively and quantitatively by the high number of duplicates in this network. Combined
with experimental work, this analysis allows us to better understand the role of high
redundancy in plant signalling networks and how it underpins the interaction between host and
parasite and their co‐evolution.

_____________________________________________________________________________

Orkun S. Soyer was born in Istanbul, Turkey on 5 July 1975. After studying Chemistry at Bogazici University, he received a PhD from the University of Michigan under the mentorship of Prof. Dr. Richard A. Goldstein. During his PhD thesis, Orkun co‐developed a site‐class model of protein evolution and applied this model to the analysis of protein sequences, specifically G‐Protein Coupled Receptors and Transporters. From April 2004 until September 2006, Orkun was a postdoctoral researcher in the Theoretical Biology Group of Prof. Dr. Sebastian Bonhoeffer at the Swiss Federal Institute of Technology (ETH) in Zürich. His work during this period concentrated on the modeling of biological pathways, with a specific emphasis on questions related to their evolution. After spending two years as independent researcher at the Microsoft Research ‐ University of Trento Centre for Computational Biology in Trento, Italy, Orkun joined University of Exeter in September 2009 as a lecturer. He is currently leading a research group there within the Systems Biology science stream. Orkun's current research aims to understand the structure and dynamics of biological networks within an
evolutionary framework with specific projects on signalling and metabolic networks.