Seminar by Mathias Luidor Heltberg

Chaotic Dynamics in Transcription Factors: Enhancement of Low Affinity Genes,
Efficient Protein Complex Formation and Generation of Population Heterogeneity

Mathias Luidor Heltberg (NBI)

The control of proteins by a transcription factor with periodically varying concentration exhibits intriguing dynamical behaviour. Even though it is accepted that transcription factors vary their dynamics in response to different situations, insight into how this affects downstream genes is lacking. Here, we investigate how oscillations and chaotic dynamics in the transcription factor NF-κB can affect downstream protein production. We describe how it is possible to control the effective dynamics of the transcription factor by stimulating it with an oscillating ligand. We find that chaotic dynamics is an effective way to modulate gene expression and specifically to up-regulate certain families of low- affinity genes, even in the presence of extrinsic and intrinsic noise. Furthermore, this leads to an increase in the production of protein complexes and the efficiency of their assembly. Finally, we show how chaotic dynamics creates a heterogeneous population of cell states, and describe how this can be beneficial in multi-toxic environments.