Figure 7.

Dependence of protein production on the network parameters with feedback. (A) Protein levels as functions of $k_{t1}/k_{f1}$ and $k_b$ with negative feedback using parameters in Table 1 and Table 2. The scale for the $\left[P\right]$ production is shown in the color spectrum. The dependence of $\left[P\right]$ on $k_{t1}$ and $k_b$ is categorized into three regimes (see text for details). Points on the dashed line separating regime II and regime III satisfy $k_b\left[M\right]=k_{t1}$. The major pathway in the transcription process in each regime is shown on the right. The arrow indicates the data point resulting from using the value of $k_{t1}$ and $k_b$ in Table 1. (B) Expression level of proteins as functions of $k_{t2}/k_{-f2}$ and $k_b$ with negative feedback using the parameters in Table 1 and Table 2. The dependence of $\left[P\right]$ on $k_{t2}$ and $k_b\left[M\right]$ is categorized into three regimes. Points on the dashed line separating regime I and regime II/III satisfy $k_b\left[M\right]=k_{-f2}$. The corresponding major transcription pathways are shown on the right. The data point corresponding to the arrow results from using the value of $k_{t2}$ and $k_b$ in Table 1.