FIG. 3.

Analysis of a C-terminally truncated ERK5 expressed in yeast. (A) Expression of a MET25 promoter-regulated ERK5(1-407)-HA restores high temperature growth, but not caffeine resistance, in the slt2Δ mutant. Wild-type (WT, strain p82a) and P82aslt2Δ (slt2Δ) cells containing either empty PEW415 vector (E), pERK5(1-407)-HA, or pERK5(1-407(AEF))-HA were grown for 3 days at the indicated temperature on DO medium lacking uracil and methionine. (B) Phosphorylation of myelin basic protein (MBP) by the ERK5(1-407)-HA immunoprecipitated from extracts of unstressed or heat-shocked (1 h at 37°C) slt2Δ single-mutant and slt2Δ mkk1Δ mkk2Δ triple-mutant cells. Immunoprecipitated fractions were also Western blotted and probed with anti-HA antiserum.