Figure 1.

Model of genetic regulation with a positive autoregulatory feedback loop. The transcription factor activator (TF-A) activates transcription with a maximal rate kf when phosphorylated (P) and binds as a dimer to specific responsive-element DNA sequences (TF-REs). TF-A is degraded with rate kd and synthesized with rate Rbas.

Wang et al. BMC Systems Biology 2012 6(Suppl 1):S9   doi:10.1186/1752-0509-6-S1-S9