Relationship between cell proliferation, chromatin template activity and accumulation of nuclear proteins

Abstract

Trypsinization of confluent monolayers of WI-38 cells causes an extensive loss of nuclear proteins. The loss of nuclear proteins is restored only several hours after the cells have been replated at a lower density in 10% serum. When trypsinized fibroblasts are replated at a lower density in 10% serum, there is also a sustained progressive increase in the template activity of isolated nuclei, eventually leading to DNA synthesis and cell division. If 0.3% serum is used instead of 10%, there is a modest increase in nuclear template activity, but not accumulation of nuclear proteins and no DNA synthesis cr cell division.