Figure 9.

In vivo phosphorylation of a fragment of Gcn4 encompassing residues 62–202 fused to a triple Myc epitope and expressed from the CUP1 promoter. The upper phosphorylation band (indicated by an arrow) is 30–40% as intense as the lower band in lanes 1 and 5 and is undetectable in the other lanes, even upon prolonged exposure (we estimate the limit of detection at <2% of the main band). Lane 4 is a no-tag control. CHX, cycloheximide treatment (1 μg/ml, 30 min); a.a. starv, 30-min incubation in YNB medium lacking all amino acids.