title: Regulation of deoxynucleoside kinase activities in rat liver mitochondria.
abstract: The activities of TdR kinase2 (ATP: thymidine 5'-phosphotransferase, EC 2.7.1.21), AdR kinase (ATP: deoxyadenosine 5'-phosphotransferase, EC 2.7.1.76), GdR kinase (ATP: deoxyguanosine 5'-phosphotransferase, without EC number), ATP (Mg2+)-ase (ATP phosphohydrolase, EC 3.6.1.3), nucleoside diphosphatase (nucleoside diphosphate phosphohydrolase, EC 3.6.1.6), nucleoside phosphotransferase (AMP: deoxynucleoside phosphotransferase, EC 2.7.1.77) and ribonucleotide 5'-diphosphate reductase (EC 1.17.4.1) were assayed in mitochondria of normal and regenerating rat liver. The activities of deoxynucleoside kinases are regulated: (a) by feedback inhibition of TdR kinase with dTTP and dCTP, and GdR kinase with dGTP; (b) GdR and AdR kinases by AdR and GdR inhibition, respectively; (c) by stimulation of GdR kinase with dTDP, dTTP and dATP. The stimulatory effects are correlated with changes of ATP (Mg2+)-ase and NDP-ase activities in regenerating liver mitochondria.
mesh_terms: D017766:Acid Anhydride Hydrolases; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D003853:Deoxyribonucleosides / Q000494:pharmacology; D003854:Deoxyribonucleotides / Q000494:pharmacology; D008115:Liver Regeneration; D008930:Mitochondria, Liver / Q000201:enzymology*; D009705:Nucleosides / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010770:Phosphotransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor); D051381:Rats; D011919:Rats, Inbred Strains; D012262:Ribonucleoside Diphosphate Reductase / Q000378:metabolism
chemical_list: D003853:Deoxyribonucleosides; D003854:Deoxyribonucleotides; D009705:Nucleosides; D012262:Ribonucleoside Diphosphate Reductase; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020018:deoxyribonucleoside kinases; C021892:nucleoside phosphotransferase; D010744:Phosphoric Monoester Hydrolases; D017766:Acid Anhydride Hydrolases; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; C023837:nucleoside-diphosphatase