Dose Response Relationship in Anti-Stress Gene Regulatory Networks
Figure 2
Analogy between the Anti-Stress Gene Regulatory Network and Proportional Negative Feedback Control System
(A) The generalized anti-stress gene regulatory system. Stressor S increases production of controlled variable Y, which is cleared by gene product G; Y activates transcription factor T, which upregulates gene expression of G; r0 − r3 are local gains.
(B) Proportional negative feedback system and its closed-loop gain. A is the open-loop gain, F is the feedback gain, and AF is the loop gain.
(C) The feedback system in (A) is rearranged so that S is the input, and the species of interest (Y, T, and G) is positioned as the output. The systems-level gain for each of the species can be generalized in terms of the open-loop gain (r0, r0r1, r0r1r2 for Y, T, G, respectively) and loop gain |r1r2r3|, conforming to the closed-loop gain in (B).