FIG. 8.

Regulation of RIZ1 methyltransferase activity by estrogen. The same amounts of nuclear extracts (500 μg) from E2-treated or control MCF-7 cells or from AdRIZ1-infected cells were immunoprecipitated with preimmune serum or RIZ1 serum anti-KG7.1S. (A) The immunoprecipitates were then assayed for HMT activity by using free histones as substrates. (B) Also, the immunoprecipitates from AdRIZ1-infected cells were analyzed by immunoblot analysis with RIZ1 monoclonal antibody 2D7. Panel A shows fluorography, indicating methylation of histone H3. Panel B shows that E2 treatment did not alter RIZ1 protein amounts.