FIGURE 3:

Mpk1(Y268C) and Mpk1(Y268A) rescue mpk1∆ and mkk1∆mkk2∆ cells even when mutated in their TEY motif. (A) mpk1Δ and (C) mkk1∆mkk2∆ cells expressing the indicated Mpk1 molecules were plated at five dilutions on plates containing YPD supplemented with 15 mM caffeine (left) or plates without caffeine (YNB(–URA); right). Western blot analysis with the indicated antibodies was performed on protein lysates prepared from (B) mpk1∆ and (D) mkk1∆mkk2∆ cells expressing the indicated Mpk1 molecules. (E, F) Mpk1(Y268C+D326N) and Mpk1(Y268C+Y238F) rescue mpk1∆ (E) but not mkk1∆mkk2∆ (F) cells.