Figure 4

Separase executes sister-chromatid separation and nucleolar segregation during mitotic slippage. (A, B) Separase-mediated cohesin cleavage is required for sister-chromatid separation during mitotic slippage. Cells of a strain SCU404 (bub2Δ CEN-GFP GAL-SCC1-RRDD) were released from α-factor into the nocodazole-containing SGalR medium to induce the non-cleavable SCC1-RRDD (time 0), as described in Figure 1. Representative cells at the 6 h time point are shown. The data for bub2Δ cells are taken from Figure 1. (C) Nucleolar segregation during mitotic slippage. Cells of strains SCU893 (WT) and SCU151 (bub2Δ) strains with the plasmid pSCU740 (pGFP-NOP1) were released from α-factor into nocodazole-containing medium (time 0), as described in Figure 1. GFP-tagged Nop1 (nucleolar protein) and DAPI images are shown at the 6 h time point.