Effects of Four Different Regulatory Mechanisms on the Dynamics of Gene Regulatory Cascades

Sandeep Krishna, NCBS Bangalore

Gene regulatory cascades (GRCs) commonly occur in cellular molecular networks. A given logical function in these cascades, such as the repression of the activity of a transcription factor, can be implemented by a number of different regulatory mechanisms. The potential consequences for the dynamic performance of the GRC of choosing one mechanism over another have not been analysed systematically. I'll talk about a synthetic GRC in Escherichia coli, developed by some experimental collaborators of mine, which allowed us to directly compare the dynamics of four different regulatory mechanisms, affecting the transcription, translation, stability, or activity of a transcriptional repressor. We developed a biologically motivated mathematical model which is sufficient to reproduce the response dynamics determined by experimental measurements. We find that dynamic differences between regulatory mechanisms at an individual step in a multi-step GRC are often concealed in the overall performance of the GRC.