Noise Propagation and Signaling Sensitivity in Biological Networks: A Role for Positive Feedback

摘要: Interactions between genes and proteins are crucial for efficient processing of internal or external signals, but this connectivity also amplifies stochastic fluctuations by propagating noise components. Linear (unbranched) cascades were shown to exhibit an interplay the sensitivity changes in input signals ability buffer noise. We searched biological circuits that can maintain signaling while minimizing propagation, focusing on cases where is characterized rapid fluctuations. Negative feedback type noise, buffering comes at expense even greater reduction sensitivity. By systematically analyzing three-component circuits, we identify positive as a central motif allowing propagated maintaining long-term signals. show analytically presence results from improved averaging over time, discuss detail particular implementation control nutrient homeostasis yeast. As design networks optimizes multiple constraints, be used improve without compromise