Figure 3.

Different genes exhibit different induction kinetics in response to Msn2. (A–D) Induction kinetics for four Msn2-inducible genes following estradiol addition to strains containing wild-type MSN2 under control of the hybrid Z₄EV transcription factor. Blue circles: fold increase in gene transcript levels relative to that immediately prior to estradiol addition; solid red line: best fit of the data for each gene to the function f(t) = f₀ + V_max · tⁿ/(Kⁿ + tⁿ); dashed line: tangent line to the curve at f(t) = V_max/2, whose extrapolation to the x-axis provides the measure of the time delay in response to Msn2 induction. (E–H) Induction kinetics for the genes shown in (A–D) following estradiol addition to strains containing MSN2^6A under control of the hybrid Z₄EV transcription factor. (I) Histogram of time delay values for the 96 genes induced more than 2-fold in both the MSN2 wild-type and MSN2^6A strains and whose induction values are reasonably fit by the Hill curve. Blue line: delay values in the MSN2 wild-type strain; red line: delay values in the MSN2^6A mutant strain. (J) Scatter plot of the delay time for each gene in I in the MSN2^6A strain relative to that in the MSN2 wild-type strain. (K) Histogram of rates of induction, i.e. the slope of the tangent line to the fitted curve at f(t) = V_max/2, for the 96 genes in (I). Blue line: delay values in the MSN2 wild-type strain; red line: delay values in the MSN2^6A mutant strain.