FIG. 3.
Chromatin association of the E2 protein during the cell cycle. (A) CHOBgl40 cells were synchronized in metaphase, collected by mitotic shake-off and then released into the cell cycle. At the indicated time, cells were collected and subjected to biochemical fractionation described for Fig. 1B, and cell synchronization was confirmed by flow cytometry analysis. Equivalent amounts of each extract (extract of 106 cells for S and P lanes and of 2 × 105 cells for Sol. fraction) were subjected for immunoblotting with E2-specific antibodies. Sol., soluble.