Table 1.

Modeling two mechanisms of microRNA action in the simplest linear model

Observable value	Initiation(k1)	Step after initiation, cap-independent(k2)	Elongation (k3)
Wild-type cap
Steady-state rate	decreases	decreases	no change
Relaxation time	increases slightly	increases slightly	no change
A-cap
Steady-state rate	decreases	no change	no change
Relaxation time	no change	increases drastically	no change

MicroRNA action effect is described for the protein synthesis steady rate and the relaxation time. It is assumed that the ribosome assembly+elongation step in protein translation, described by the k₃ rate constant, is not rate limiting.