The dependence of DNA synthesis on protein synthesis in HeLa S3 cells

The rate of DNA synthesis in HeLa S3 cells, as measured by incorporation of C¹⁴-labeled thymidine, is strongly dependent on protein synthesis at all times during the S phase. The relation between the rate of DNA synthesis and the rate of protein synthesis is linear when measured two or three hours after reducing the rate of protein synthesis with either puromycin or cycloheximide. The effect is manifested rapidly, is found in both random and synchronized cultures, and is independent of the method of synchronization.