FIG. 3.

Pulse-chase analysis further shows defective pre-rRNA processing in ARB1 depletion cells. Strains YDH209 (WT) and YDH226 (P_GAL-UBI-R-FH-ARB1) were grown in SC_Gal-Met medium to an A₆₀₀ of 1.2, then shifted to SC_Glu-Met medium for 18 h. Cells were labeled with [methyl-³H]methionine for 2 min and subsequently chased with 4 ml of 1 mg/ml unlabeled methionine for the time points indicated. Total RNA was isolated, and samples containing 70,000 dpm were separated on a 1.2% agarose-formaldehyde gel, transferred to a nylon membrane, and exposed to film. Lanes 9 and 10 depict a longer exposure of lanes 5 and 6.