Inhibitory effect of calcium-binding protein regucalcin on Ca2(+)-activated DNA fragmentation in rat liver nuclei.
Incubation of isolated rat liver nuclei with ATP, NAD+, and micromolar Ca2+ concentrations of various metal ions resulted in extensive DNA hydrolysis. Half-maximal activity occurred with 1.0 microM Ca2+ added, and saturation of the process was observed with 10 microM Ca2+. The Ca2+ (10 microM)-activated DNA fragmentation was inhibited by the presence of Ca2(+)-binding protein regucalcin isolated from rat liver cytosol. The inhibitory effect of regucalcin was complete at 0.5 microM. At 25 microM Ca2+ added, such an effect of regucalcin (1.0 microM) was not seen. Regucalcin also inhibited Ca2(+)-activated DNA fragmentation in the presence of calmodulin (10 and 20 micrograms). The results show that regucalcin can inhibit the Ca2(+)-activated DNA fragmentation due to binding the metal, suggesting a role in regulation of liver nuclear functions.
Yamaguchi
M
M
Department of Environmental Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
Sakurai
T
T
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D002147:Calmodulin / Q000494:pharmacology; D002265:Carboxylic Ester Hydrolases; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D004706:Endodeoxyribonucleases / Q000378:metabolism; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008670:Metals / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D015238:Sulfotransferases
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D047908:Intracellular Signaling Peptides and Proteins; D008670:Metals; D000255:Adenosine Triphosphate; D004247:DNA; D015238:Sulfotransferases; C028152:alcohol sulfotransferase; D004706:Endodeoxyribonucleases; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat; D002118:Calcium