FIGURE 1.

Mitotic phosphorylation of HDAC1 and -2. Whole cell protein extracts were prepared in the presence of protein phosphatase inhibitors except for samples used in the CIP assay. For thymidine double block, protein and FACS samples were prepared 6, 7, 8, 10, and 12 h after second release. For mitotic block, protein samples were prepared after 20-h treatment with taxol or nocodazole (Noc). A and B, protein samples were analyzed by immunoblotting using the indicated antibodies. The state of phosphorylation is indicated as O, P, or P*, representing unmodified, phosphorylated, and hyperphosphorylated isoforms, respectively.