Role of Sch9, tap42, or tip41 in the A2 to A3 switch in pre-rRNA processing.

<p>(A) Pre-rRNA processing before and after diauxic shift in the yeast strain lacking Sch9 kinase (<i>sch9Δ</i>) or in the <i>tap42-11</i> mutant. The OD₆₀₀ values of harvested samples are shown above the lanes. Northern blot using the A2–A3 probe. (B) Pre-rRNA processing before and after diauxic shift in the strain expressing the hyperactive mutant Sch9-2D3E grown in SDC media. Samples were harvested at indicated OD₆₀₀, and total RNA was analyzed by northern blotting using probe A2–A3. (C) The <i>sch9Δ</i> or wild-type strains were treated by rapamycin at OD₆₀₀ = 2, and total RNA was isolated at indicated time points and analyzed by northern blotting (probe A2–A3). (D) The <i>tap42-11</i> mutant and <i>tip41Δ</i> strain were treated with rapamycin as in (C).