Fig. 1

Irr1 protein can be present outside the nucleus. Growth arrest in G1 phase is accompanied by the appearance of Irr1 in the cytoplasm. Rows, top to bottom, show Irr1-GFP signal in cells in exponential phase of growth in YPD medium, in post-diauxic phase (ca. 24 h in YPD), following 22 h of nitrogen starvation in SD-N medium, and following α-factor treatment (6 μg/ml for 3 h). Spc42-mCherry—spindle pole body protein fused with mCherry, a nuclear marker, DAPI DNA stained with DAPI, DIC transmitted light