Model extension 4: Upregulation of one or more miRNAs inhibits Atf3 mRNA and/or protein.

<p>A, The conceptual model of the miRNA inhibitory pathway for Atf3 transcriptional regulation. Symbols are as for <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003597#pcbi-1003597-g001" target="_blank">Figure 1C</a>. B, The predicted dynamical variation in miRNA concentration. C, D and E, Predicted concentrations of total Atf3 mRNA (i.e. mRNA + miRNA.mRNA complex) (C, blue lines), Atf3 protein (D, green lines) and Egr1 mRNA (E, pink lines) when the rate of degradation of Atf3 mRNA within the miRNA.mRNA complex is the same as for degradation of free Atf3 mRNA (solid lines), is increased 2-fold (long dashed lines) or is increased 4-fold (short dashed lines). The predicted curves are superimposed on the experimental data (solid black lines, right axes) to which a spline curve was fitted.