Comparing feedback strategies for minimizing noise in gene expression event timing

Abstract

Many cellular events occur when their corresponding regulatory proteins attain critical thresholds. Can cells schedule such events with precision by controlling the dynamics of the proteins? We investigate this question by considering a simple gene expression model that consists of switching the gene between OFF and ON states and degradation of the protein. Because feedback regulation is a pervasive method of control in biological systems, we analyzed three feedback mechanisms (protein regulates either its own transcription, or the rate at which gene turns ON, or the rate at which gene turns OFF) for their abilities to suppress noise in timing. We show that in the limiting case where the protein does not degrade, feedbacks always amplify noise in event timing.