Transients in the frequency response of the EGFR and GPCR systems. (A&C) The rise time, t99 taken for the transient term in frequency response to decay by 99% was normalized with the input wavelength λ and is plotted as a function of frequency for the EGFR (A) and GPCR (C) systems. The normalized rise time quantifies the number of input pulses beyond which the steady-state response is reached. The black dotted lines in panels A and C are drawn at a normalized rise time value of 1. (B&D) The input wavelength, λcrit for which the response reaches steady-state in a single input pulse (t99/λ = 1) is plotted as function of the extent of downregulation, D for the EGFR (B) and the desensitization rate kds for the GPCR (D). For input wavelengths λ > λcrit the system responds with virtually no transient.
Shankaran et al. BMC Systems Biology 2007 1:48 doi:10.1186/1752-0509-1-48