Figure 2. Post-translational regulation of DNMT1 expression.

A. DNMT1 and DNMT3b activity was tested in Tgfbr2^{floxE2/floxE2} and Tgfbr2^fspKO mouse prostatic stromal cells as well as human CAF and NAF cells. B. Western blotting indicated elevated DNMT1 protein expression in Tgfbr2^fspKO, compared to Tgfbr2^{floxE2/floxE2} prostatic fibroblastic cells. However, RNA expression of DNMT1 and EZH2 were similarly expressed in Tgfbr2^{floxE2/floxE2} and Tgfbr2^fspKO prostatic fibroblastic cells. C. Cyclohexamide (Chx) treatment resulted in the down regulation of DNMT1 protein expression in Tgfbr2^{floxE2/floxE2} prostatic fibroblasts. Antagonizing proteosome activity (MG132) restored DNMT1 expression in Chx treated cells. DNMT1 protein expression was unaffected by Chx or MG-132 in Tgfbr2^fspKO prostatic fibroblasts. Columns in the graph are mean and SD of six densitometric readings adjusted for actin in independent blots prepared from three randomly-selected samples per treatment group (p < 0.0001).