Suppressive effect of endogenous regucalcin on the enhancement of protein synthesis and aminoacyl-tRNA synthetase activity in regenerating rat liver.
The effect of regucalcin, which is a regulatory protein in Ca2+ signaling, on protein synthesis in regenerating rat liver was investigated. Protein synthesis was assayed in a reaction mixture containing the 5500 g supernatant fraction in the presence of [3H]leucine. The presence of anti-regucalcin monoclonal antibody (100 and 150 ng/ml) in the reaction mixture caused a significant elevation of in vitro protein synthesis. This elevation was completely prevented by the addition of regucalcin (1.0 microM). Regenerating liver after partial hepatectomy (HPX) induced a significant increase in protein synthesis. This increase was significantly enhanced by the presence of anti-regucalcin monoclonal antibody (100 ng/ ml). This enhancement was remarkable at 24 and 48 h after HPX. [3H]Leucyl-tRNA synthetase activity in the 105000 g supernatant fraction (cytosol) of the liver homogenate from normal rats was significantly raised by the presence of antibody (100 and 150 ng/ml) in the enzyme reaction mixture. Regenerating liver caused a significant elevation of the enzyme activity at 24, 48, and 72 h after HPX. This elevating was significantly enhanced in the presence of antibody (100 ng/ml). The present study suggests that endogenous regucalcin has a suppressive effect on the enhancement of protein synthesis in regenerating rat liver with a proliferative cells.
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
Y
Y
Tsurusaki
M
M
Yamaguchi
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000302:isolation & purification / Q000502:physiology*; D002265:Carboxylic Ester Hydrolases; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D006498:Hepatectomy; D047908:Intracellular Signaling Peptides and Proteins; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000201:enzymology* / Q000601:surgery; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D014176:Protein Biosynthesis; D051381:Rats; D017208:Rats, Wistar; D015238:Sulfotransferases
D000911:Antibodies, Monoclonal; D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D015238:Sulfotransferases; C028152:alcohol sulfotransferase; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat; D000604:Amino Acyl-tRNA Synthetases; D007930:Leucine; D002118:Calcium