FIG. 6.
(A) PMT2 is important for pheromone-induced activation of Mpk1. Cultures of cdc28-13 (wild type [WT]; DL2393), cdc28-13 mid2Δ (DL2435), and cdc28-13 pmt2Δ (DL2440) strains expressing Mpk1HA from pRS425 were synchronized by arrest in G1 at 37°C for 90 min, followed by treatment with 50 nM α-factor. Mpk1HA was immunoprecipitated (with the 12CA5 antibody) from extracts of cultures taken at the indicated time points. Protein kinase assays were conducted with myelin basic protein (MBP) as the substrate. The lower panel represents an immunoblot of Mpk1HA immunoprecipitates. Mpk1 is not activated in this strain background by temperature upshift (1a). (B) PMT2 is important for survival of α-factor treatment. Wild-type (1783), pmt2Δ (DL2468), and mid2Δ (DL2278) strains were grown in SD medium with limiting calcium (100 μM CaCl2) at 30°C to an A600 of approximately 0.6. α-Factor (8 μg/ml) was added to the cultures, and samples were tested for viability at the indicated times by plating onto YEPD. Plates were scored after 2 days at room temperature. The results shown are the mean and standard deviation from three independent experiments.