Reversible effect of calcium-binding protein regucalcin on the Ca(2+)-induced inhibition of deoxyuridine 5'-triphosphatase activity in rat liver cytosol.
The effect of regucalcin, a calcium-binding protein isolated from rat liver cytosol, on deoxyuridine 5'-triphosphatase (dUTPase) in the cytosol of rat liver was investigated. Addition of Ca2+ up to 5.0 microM to the enzyme reaction mixture caused a significant decrease of dUTPase activity, while Zn2+, Cd2+, Co2+, Al3+, Mn2+ and Ni2+ (10 microM) did not have an appreciable effect. The Ca(2+)-induced decrease of dUTPase activity was reversed by the presence of regucalcin; the effect was complete at 1.0 microM of the protein. Regucalcin had no effect on the basal activity of the enzyme. Meanwhile, the reversible effect of regucalcin on the Ca2+ (10 microM)-induced decrease of dUTPase activity was not altered by the coexistence of Cd2+ or Zn2+ (10 microM). The present data suggest that liver cytosolic dUTPase is uniquely regulated by Ca2+ of various metals, and that the Ca2+ effect is reversed by regucalcin.
Yamaguchi
M
M
Department of Environmental Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
Sakurai
T
T
D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors* / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000502:physiology*; D002265:Carboxylic Ester Hydrolases; D003600:Cytosol / Q000201:enzymology*; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008099:Liver / Q000201:enzymology*; D008297:Male; D011755:Pyrophosphatases / Q000037:antagonists & inhibitors*; D051381:Rats; D011919:Rats, Inbred Strains; D015238:Sulfotransferases
D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D015238:Sulfotransferases; C028152:alcohol sulfotransferase; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat; D011755:Pyrophosphatases; C020020:dUTP pyrophosphatase; D002118:Calcium