Fig. 4. Mck1 is not involved in the transcriptional regulation of HSL1. (A) The oscillation of SWE1 or HSL1 mRNA levels during cell cycle progression in various strains that were synchronized with α-factor was determined by northern blotting, using the SWE1, HSL1 and ACT1 probes. Experimental conditions were as described in the legend to Figure 1C. RNA blot hybridization with the SWE1, HSL1 and ACT1 probes. (B) Changes in the relative intensity of SWE1 or HSL1 mRNA. The amount of SWE1 or HSL1 mRNA in (A) was normalized to a constant level of ACT1 mRNA. In each case, the individual maximum value was referred to as 1. Time 0 represents the point of release from G₁ phase arrest.