Stimulatory effect of calcium-binding protein regucalcin on phosphatase activity in the brain cytosol of rats with different ages.
The effect of calcium-binding protein regucalcin on phosphatase activity in the brain cytosol of rats with different ages was investigated. The presence of regucalcin (10(-8) and 10(-7) M) in the enzyme reaction mixture caused a significant increase of neutral p-nitrophenylphosphatase activity in the brain cytosol obtained from 5- and 50-week-old rats. This increase was seen in the absence or presence of calmodulin (2 microg/mL) and calcium chloride (100 microM). Brain cytosolic phosphatase activity was not significantly altered by S-100A (10(-6) M) or calbindin (10(-7) M), which is a calcium-binding protein. Regucalcin-increased phosphatase activity was clearly decreased by N-ethylmaleimide, a modifying reagent of thiol(SH)-group, suggesting that regucalcin acts on the SH-group of the enzyme. Moreover, the presence of anti-regucalcin monoclonal antibody (50-200 ng/mL) in the reaction mixture caused a significant decrease of brain cytosolic phosphatase activity, suggesting that the endogenous regucalcin has a stimulatory effect on the enzyme activity. These results suggest that regucalcin plays a role in the regulation of protein phosphatase in rat brain cytosol.
Hanahisa
Y
Y
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Shizuoka City, Japan.
Yamaguchi
M
M
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000906:Antibodies / Q000276:immunology; D001921:Brain / Q000187:drug effects* / Q000201:enzymology*; D002122:Calcium Chloride / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000276:immunology / Q000494:pharmacology*; D002147:Calmodulin / Q000494:pharmacology; D002265:Carboxylic Ester Hydrolases; D002614:Chelating Agents / Q000494:pharmacology; D003600:Cytosol / Q000187:drug effects* / Q000201:enzymology*; D004229:Dithiothreitol / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005260:Female; D047908:Intracellular Signaling Peptides and Proteins; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D015238:Sulfotransferases
D000906:Antibodies; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D002614:Chelating Agents; D047908:Intracellular Signaling Peptides and Proteins; D013439:Sulfhydryl Reagents; D004533:Egtazic Acid; D015238:Sulfotransferases; C028152:alcohol sulfotransferase; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat; D010744:Phosphoric Monoester Hydrolases; D002122:Calcium Chloride; D005033:Ethylmaleimide; D004229:Dithiothreitol