FIG. 4.

SIRT2 stable transfectants that overexpress the wild-type phosphorylated forms of SIRT2 return to G₁ less effectively than cells expressing mutant SIRT2 or nonhyperphosphorylated cell lines. Cell lines were treated with nocodazole for 20 h, and then the nocodazole was washed out. Cells were collected for flow cytometry at the indicated times after the initiation of nocodazole washout. In panels A to E, graphs indicate the percentage of cells with a 2N and 4N DNA contents at each time point for each cell line. Cell lysates were harvested at each time point and immunoblotted with SIRT2 peptide antibody (results shown below each graph). UT, untreated, unsynchronized cells. These results are representative of those obtained in multiple experiments. The more hyperphosphorylated the cell line is, the slower the exit from mitosis is.