FIG. 4.
Thr-162 phosphorylation of Kin28p is not essential for transcriptional induction. (A) Osmotic stress. Cells containing KIN28 (wild type [WT]) or kin28T162A (strains YGK26 and YGK42, respectively) were inoculated into YPD containing 0.9 M NaCl and maintained. RNA was extracted at various times after induction, and transcripts were analyzed by Northern blotting with a probe derived from GPD1. Signal intensities were quantitated by phosphorimaging. (B) Galactose induction. KIN28 or kin28T162A cells containing the galactose-inducible lacZ reporter plasmid pAF21 (strains YJK1747 and YJK1749) and growing in raffinose-containing medium were collected at various times following induction of the galactose promoter by addition of 30% galactose to a final concentration of 2%. β-Galactosidase activity was measured with o-nitrophenyl-β-d-galactopyranoside (ONPG) as a substrate.