FIG. 7.

The H-3/4 domain of HES-1 mediates the repression of the cell cycle proteins PCNA and p21. Expression of induced, Flag-tagged proteins in the WT, ΔS, and ΔR HES-1 PC12 cell lines was verified by anti-HES-1 and anti-Flag Western analysis (upper two panels). Induction of both WT and ΔS HES-1 reduced the level of PCNA and p21 proteins, whereas induction of the ΔR HES-1 protein had no significant effect on either PCNA or p21 (lower 2 panels). Neither expression of WT HES-1 nor the ΔS and ΔR HES-1 mutant proteins affected the level of cyclin D1 (middle panel).