Figure 5. Rap1-containing promoters exhibit superior noise suppression.

(A) Example of an extended stochastic model including TF noise based on Model 1. (B–G) Noise levels (CV) of RPmRNAs with gene silencing and noisy transcription factor levels as determined by stochastic simulation for Model 1 (B,D,F) and Model 4 (C,E,G). For each parameter combination, 500 simulations into steady state were performed. (B) and (C): Representative simulation time courses and mean trajectory (n = 500) of RPmRNA dynamics at intermediate silencing strength (K_a = 0.40) for Model 1 (B) and Model 4 (C). Black vertical marker: starting point of sampling for CV evaluations. For a fair comparison, Ifh1 levels yielding equivalent mean RPmRNA levels are shown. (D) and (E): RPmRNA noise when simultaneously varying the speed of gene silencing (relative to the nominal value) and total Ifh1 levels (for CV_{Ifh1_T}≈const); (F) and (G): RPmRNA noise as a function of the equilibrium constant of gene reactivation (K_a) and of Ifh1 noise levels (CV_{Ifh1_T}) for a constant Ifh1 level (430 molecules).