Cell cycle regulated synthesis of stable mouse thymidine kinase mRNA is mediated by a sequence within the cDNA

Abstract
The cDNA for mouse thymidinekinase (TK) was isolated from a cDNA library in lambda-gt11 and sequenced. It was used as a probe to follow the time course of TKmRNA expression in growth stimulated mouse fibroblasts. Linked to the HSV-TK promoter the cDNA was able to transform LTK-cells to the TK phenotype. The transformed cells expressed the TKmRNA and enzyme activity in a growth dependent fashion suggesting that the regulatory element is localized on the cDNA.