The trr4-1 pre-tRNAArgCCG accumulates in nuclei when PUS3 is depleted. (A)Wild-type cells (PUS3 TRR4), trr4-1 cells (PUS3 trr4-1), cells containing PUS3 under control of the GAL1 promoter (GAL–PUS3 TRR4), and trr4-1 cells containing PUS3 under control of the GAL1 promoter (GAL–PUS3 trr4-1)were grown at 25°C in galactose-containing media and switched to glucose media at time 0. After 24 h, cells were subjected to in situ hybridization to detect tRNAArgCCG (panels a, c, e, g). Filled arrowheads denote cells in which tRNAArgCCG was detected inboth the nucleus and the cytoplasm, while open arrowheads denote cells where tRNAArgCCG was primarily detected in nuclei. Nuclei were visualized by staining DNA with DAPI (shown in blue in panels b, d, f, h). (B) As a control, GAL–PUS3 trr4-1 cells were subjected to in situ hybridization to detect tRNAGlyGCC (right). DNA was visualized with DAPI (left). In this strain, as well as in all strains shown in A, tRNAGlyGCC was primarily cytoplasmic.
