Overexpression of Thymidine Kinase mRNA Eliminates Cell Cycle Regulation of Thymidine Kinase Enzyme Activity

Regulation of Thymidine Kinase Protein Stability

The mechanism of posttranscriptional regulation of thymidine kinase (TK) enzyme levels following serum stimulation of quiescent cells has been investigated using stably transfected Rat 3 (TK1 cells containing the human TK complementary DNA linked to a hybrid SV4O/human TK promoter. These cells expressed a wild-type human TK mRNA at relatively constant levels during the first G1 and S phase afte...

Regulation and biological function of thymidine kinase.

Introduction Thymidine kinase (TK) is an enzyme of the salvage pathway of nucleotide biosynthesis. There are only a few organisms (yeast being one of them) that do not have at least one enzyme of this specificity. Also most DNA viruses, from bacteriophages to human pathogenic viruses such as herpes and vaccinia, code for TKs [l]. Some of these viral TKs are of special interest; they are useful ...

Restriction Enzyme Analysis of Thymidine Kinase Gene in Four Iranian Isolates of Herpes Simplex Virus Type 1

Regulation of the proliferating cell nuclear antigen cyclin and thymidine kinase mRNA levels by growth factors.

The enzymes of the DNA synthesizing machinery constitute a group of gene products that are generally expressed co-ordinately at the G1/S boundary of the cell cycle. We have investigated how growth factors regulate the steady-state mRNA levels of two of these genes, the PCNA (proliferating cell nuclear antigen)/cyclin and the thymidine kinase genes. To detect the PCNA/cyclin mRNA, we isolated a ...

Human Thymidine Kinase

Cytosolic thymidine kinase (EC 2.7.1.21) has been purified 5200-fold to apparent homogeneity from normal human placenta. The purification includes sequential affinity chromatography on blue-Sepharose and a thymidine column. The molecular weight of the enzyme determined by gel filtration and sucrose density ultracentrifugation is 92,000. The subunit molecular weight is 44,000, suggesting that t...