Effects of cycloheximide on chromatin-bound and -unbound PCNA in HeLa cells

We examined the effects of cycloheximide on the amount of chromatin-bound and -unbound PCNA subpopulations in HeLa cells. The chromatin-bound PCNA content decreased rapidly in the presence of cycloheximide, whereas the reduction of the total amount of PCNA was minimal even 24 h after the treatment with cycloheximide. From these data, the half-life of PCNA was estimated to be 31.0 h for chromatin-bound PCNA and 276.8 h for the total.