Fig. 5. The mRNA levels of cru1 are regulated by cAMP/PKA. (A) The levels of cru1 mRNA are regulated by nutritional conditions. FB1 cells were grown in nutrient-rich medium (YPD), complete medium (CMD) and minimal medium (MMD) until OD₆₀₀ 0.5. RNA was isolated and 10 µg of RNA was loaded per lane. The same filters were hybridized in succession with the probes indicated on the left. A quantification of the cru1 signal relative to the rRNA signal is shown on the right. (B) Northern analysis of cru1 mRNA levels in response to cAMP. FB1 cells were grown for 6 hours in CMD containing the indicated concentrations of cAMP, and 10 µg of total RNA was loaded per lane. Quantification of the relative signal is shown on the right. (C) Levels of cru1 mRNA in cAMP/PKA mutants. Total RNA from the strains indicated on the top growing in CMD until mid-exponential phase was isolated and subjected to northern analysis with the probes indicated on the left. Quantification of the relative signal is shown on the right.