Regensburg 2013 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 2: Statistical Physics in Biological Systems I (joint with BP)
DY 2.3: Talk
Monday, March 11, 2013, 10:00–10:15, H47
Caveats in Modelling Coarse-Grained Descriptions of a Bistable Frustrated Unit — •Darka Labavić1, Hannes Nagel2, Wolfhard Janke2, and Hildegard Meyer-Otrmanns1 — 1School of Engineering and Science, Jacobs University Bremen — 2Institut für Theoretische Physik, Universtät Leipzig
From a coarse-grained perspective the motif of a self-activating species, activating a second species which acts as its own repressor, is widely found in biological systems. In [1] we studied this model on the proteonic level in a fully stochastic version. In [2] we zoom into the level of genes which are described as directly producing proteins. We focus on the effect that inherent time scales of the underlying scale of this genetic circuit can have on the bifurcation patterns on the coarser scale of proteins. Depending on the ratio of binding and unbinding rates of the transcription factors to the decay times of the proteins, the appropriate averaging procedure for obtaining a coarse-grained description changes and leads to sets of deterministic equations, which considerably differ in their bifurcation structure. In particular, the desired intermediate range of regular limit cycles fades away when the binding rates of genes are not fast as compared to the decay time of the proteins. Our analysis illustrates that the common topology of the widely found motif alone does not imply universal features in the dynamics.
[1] Garai A, Waclaw B, Nagel H, and Meyer-Ortmanns H, J. Stat. Mech. (2012) P01009;
[2] Labavić D, Nagel H, Janke W, and Meyer-Ortmanns H, submitted