SUMOylation contributes to Sir4 subtelomeric chromatin association during mitosis. To confirm the cell cycle stage of cultures used for cell cycle–dependent ChIP analysis (see Fig. 7 E), samples at each time point were analyzed by FACS to determine DNA content of cells in the population. The positions of 1n and 2n DNA peaks are shown. To the right, proteins derived from cell lysates harvested at the various time points were analyzed by Western blotting using anti-V5, SUMO, Clb2, and Gsp1 (load control) antibodies. Red arrowheads point to SUMOylated Scs2. Blue arrowheads point to other prominent mitotic SUMO conjugates. Molecular mass markers are shown in kD.