Figure 6.

Impact of the mRNA expression kinetics and their parameters on the mRNA concentration profile within an APC concentration gradient. (A) The steady state concentration of the target gene mRNA is compared assuming a mass action activation (dashed black line) and cooperative activation with Hill coefficients n = 2, 3, and 5 (black, dark gray, and light gray, respectively) and K_M = 23 nM in all three cases. For each curve the steady state is normalized to the respective maximal mRNA concentration. (B) The steady state concentration of the target gene mRNA is compared assuming cooperative activation with K_M values of 10, 23, 100, and 500 nM (black, dark gray, gray, and light gray, respectively). The Hill coefficient is set to n = 3 in all cases. For each curve the steady state is normalized to the respective maximal mRNA concentration. (C,D) The absolute value of the concentration changes along the curves of (A,B), respectively, are compared. The maximal calculated change in each panel is color-coded in black.