Fig. 5.

Pol III transcription is activated via Maf1 phosphorylation by CK2. Levels of newly synthesized pre-tRNA were estimated by Northern blot hybridization with tRNA^Leu intron probe and U3 probe (loading control). Quantification of pre-tRNA^Leu transcript (Upper band) was normalized to U3 snoRNA transcript. (A) Wild-type and maf1-Δ strains were grown in rich glucose medium (YPD) to exponential phase and transferred to glycerol medium (YPGly). Following 3-h incubation at 30 °C the culture was split in half; one part was transferred to YPD with 4% (vol/vol) DMSO and the second, to YPD with 200 μM TBBt in DMSO. (B) Isogenic mutants cka1-Δ cka2^t and cka1-Δ cka2^ts maf1-Δ were grown in glucose medium (YPD) at 30 °C to exponential phase and transferred to YPD prewarmed to 37 °C for 1 h.