FIG. 1.

Kin28p is a phosphoprotein. (A) Phosphatase treatment. Kin28p-HA was immunoprecipitated from native yeast lysates and incubated with lambda phosphatase (P) and/or phosphatase inhibitor (I). Samples were subject to SDS-PAGE followed by immunoblotting. (B) Electrophoretic mobilities of Kin28p point mutants. Strains carrying a kin28 deletion covered by plasmids containing HA epitope-tagged Kin28p point mutants were harvested during exponential growth, lysed directly into SDS-PAGE sample buffer, and analyzed by immunoblotting. AF denotes a T18A/Y19F double mutant. “No HA” indicates that a strain lacks HA-tagged proteins. Immunoblots produced four Kin28p species (see also Fig. 2A). WT, wild type