ISSN:
0730-2312
Keywords:
regucalcin
;
calmodulin
;
protein kinase
;
calcium-binding protein
;
liver nuclei
;
regenerating rat liver
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
The effect of Ca2+-binding protein regucalcin on protein kinase activity in the nuclei of normal and regenerating rat livers was investigated. Protein kinase activity in the nuclei isolated from normal rat liver was significantly increased by addition of Ca2+ (500 μM) and calmodulin (10 μg/ml) in the enzyme reaction mixture. Nuclear protein kinase activity was significantly decreased in the presence of EGTA (1.0 mM), trifluoperazine (TFP; 20 μM), dibucaine (10-4 M), or staurosporine (10-7 M), indicating that Ca2+-dependent protein kinases are present in the nuclei. Protein kinase activity was significantly elevated in the liver nuclei obtained at 6 to 48 h after a partial hepatectomy. Hepatectomy-increased nuclear protein kinase activity was significantly decreased in the presence of EGTA (1.0 mM), TFP (20 μM), or staurosporine (10-7 M) in the enzyme reaction mixture. The presence of regucalcin (0.1-0.5 μM) caused a significant decrease in protein kinase activity in the nuclei obtained from normal and regenerating rat livers. Meanwhile, the nuclear protein kinase activity from normal and regenerating livers was significantly elevated in the presence of anti-regucalcin monoclonal antibody (50-200 ng/ml). The present study suggests that regucalcin plays a role in the regulation of protein kinase activity in the nuclei of proliferative liver cells. J. Cell. Biochem. 71:569-576, 1998. © 1998 Wiley-Liss, Inc.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
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