Fig. 6.

The dampening effect of constitutive signals is not unique to redox signalling systems. The ERK signalling model published by Shilling et al. (48) was simulated in the presence and absence of a constitutive Epo signal. a) Activator molecules in the pathway. b) Inhibitor molecules in the pathway. The constitutive signal corresponds to a rate constant of Epo generation of 0.1. The modification of the original model only involved the addition of two reactions; i) Epo generation following zero-order kinetics and ii) Epo degradation occurring through a first order mass action reaction with a rate constant of 0.1.