FIG. 2.

ERK5 restores Rlm1p activity in the slt2Δ mutant, with activity rescue abolished by the expression of a T22I mutant Hsp90 or the loss of Mkk1/2p. (A) Expression of a YIL117c-lacZ reporter of Rlm1p activity in strains P82a, P82aslt2Δ, T22I, and T22Islt2Δ, either containing empty pG1 vector (E) or the pG1-ERK5 expression vector (ERK5). (B and C) Analysis of 37°C growth (B) and Rlm1p activity (C) in a slt2Δ mkk1Δ mkk2Δ triple mutant transformed with either empty pG1 (E) or pG1-ERK5 (ERK5) compared to the PP30 parent strain (WT). YIL117c-lacZ expression measurements were on cells either in growth at 25°C (unstressed), heat shocked from 25°C to 37°C for 1 h, or exposed to 8 mM caffeine for 1 h at 25°C.