Author response image 1. Kinetics of ³⁵S-methionine uptake in budding and fission yeasts.

S. cerevisiae (BY4742) and S.pombe wild type cells were grown to exponential phase (OD = 0.3 and 0.45) in YNB (Yeast Nitrogen Base, 2% glucose) and EMMO.5X media, respectively. 50 µCi ³⁵S-methionine (EasyTag L-[³⁵S]-methionine, NEG709A005MC, PerkinElmer) were added to 5 mL cultures and cells were collected using 0.2 µm filters at the following time points: 30 sec, 10 min, 20 min, 40 min and 60 min. Filters and aliquots of media depleted for cells were counted using a liquid scintillation counter (WALLAC 1409 DSA, Perkin Elmer) to determine the % of ³⁵S-methionine uptake (filled lines) and the % of ³⁵S-methionine remaining in the culture media (dashed lines). Blue and red curves refer to S. cerevisiae and S. pombe respectively.