Mitochondrial Thymidine Kinase and the Enzymatic Network Regulating Thymidine Triphosphate Pools in Cultured Human Cells
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چکیده
منابع مشابه
Origins of mitochondrial thymidine triphosphate: dynamic relations to cytosolic pools.
Nuclear and mitochondrial (mt) DNA replication occur within two physically separated compartments and on different time scales. Both require a balanced supply of dNTPs. During S phase, dNTPs for nuclear DNA are synthesized de novo from ribonucleotides and by salvage of thymidine in the cytosol. Mitochondria contain specific kinases for salvage of deoxyribonucleosides that may provide a compartm...
متن کاملFeedback Inhibition of Thymidine Kinase by Thymidine Triphosphate.
That the regulation of cell division and deoxyribonucleic acid synthesis is subject to some kind of chemical control in higher organisms is widely accepted (2-5). Davidson (2) has suggested that deoxyribonucleic acid synthesis takes place at critical concentrations of the deoxyribonucleoside triphosphates and that these compounds are components of a homeostatic mechanism. There are now at least...
متن کاملEvaluation of ribonucleoside and deoxyribonucleoside triphosphate pools in cultured leukemia cells during exposure to methotrexate or methotrexate plus thymidine.
Continuous exposure to inhibitory concentrations of methotrexate produces distinct rates of steady-state growth of murine leukemia L1210 and human leukemia CCRF-CEM cells in culture. Addition of thymidine to the medium produces reversal (6 to 40%) of this steady-state growth rate inhibition. This study utilized combinations of methotrexate and thymidine for an evaluation of the accompanying rel...
متن کاملHuman 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...
متن کاملEffects of thymidine on deoxyribonucleoside triphosphate pools and deoxyribonucleic acid synthesis in Chinese hamster ovary cells.
Cultured Chinese hamster ovary cells were synchronized by isoleucine starvation. Thymidine was added either during Gl or during S-phase and deoxyribonucleotide pools and the rate of DNA synthesis were measured. Addition of 1 mu thymidine to Gl cells did not appreciably influence the entry of the cells into S-phase but inhibited the rate of DNA synthesis up to 90%. The pools of dTTP, dGTP, and d...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 2007
ISSN: 0021-9258
DOI: 10.1074/jbc.m705923200