Suppressive effect of regucalcin on protein phosphatase activity in the heart cytosol of normal and regucalcin transgenic rats

Ichikawa, Emiko; Tsurusaki, Yoshinori; Yamaguchi, Masayoshi

doi:10.3892/ijmm.13.2.289

Cited by 3 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The role of regucalcin in the regulation of heart muscle function, however, has not been clarified fully. Recent studies demonstrate that regucalcin has activating effects on microsomal Ca 2+ -ATPase (18) and cytosolic superoxide dismutase (26) in rat heart, and that it has inhibitory effects on cytosolic protein phosphatase (27) and nitric oxide synthetase (28) in the heart. This study, moreover, demonstrates that regucalcin has an activating effect on Ca 2+ -ATPase, which is involved in Ca 2+ transport, in the mitochondria of rat heart.…”

Section: Discussionmentioning

confidence: 99%

“…Recently, it has been shown that regucalcin can activate Ca 2+ -ATPase, which plays a role as a Ca 2+ pump, in rat heart microsomes (18), and that it increases superoxide dismutase activity in rat heart cytosol (26). Moreover, regucalcin has been shown to have inhibitory effects on protein phosphatase (27) and nitric oxide synthase (28) activities in rat heart cytosol. Regucalcin may have a regulatory effect on heart muscle function.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Regucalcin increases Ca2+-ATPase activity in the heart mitochondria of normal and regucalcin transgenic rats

Akhter

Sawada²,

Yamaguchi³

2006

Int J Mol Med

Self Cite

View full text Add to dashboard Cite

Abstract. The role of regucalcin, a regulatory protein in intracellular signaling system, in the regulation of Ca 2+ -ATPase activity in rat heart mitochondria was investigated. Mitochondrial Ca 2+ -ATPase activity was significantly increased by increasing concentrations of CaCl 2 (2.5-50 μM). An increase in the enzyme activity was saturated at 50 μM CaCl 2 . The addition of regucalcin (10 -11 -10 -8 M) in the enzyme reaction mixture caused a significant increase in Ca 2+ -ATPase activity in heart mitochondria in the presence of 50 μM CaCl 2 . Regucalcin did not have a significant effect on mitochondrial Mg 2+ -ATPase activity. Regucalcin (10 -9 M) did not have a significant effect on Ca 2+ -ATPase activity in the presence of digitonin (10 -3 or 10 -2 %), which is a solubilization effect on membranous lipids. The effect of regucalcin in increasing mitochondrial Ca 2+ -ATPase activity was not observed in the presence of ruthenium red (10 -7 M) or lanthanum chloride (10 -7 M), which is an inhibitor of Ca 2+ uniporter. The effect of regucalcin (10 -9 M) in increasing mitochondrial Ca 2+ -ATPase activity was not significantly enhanced in the presence of calmodulin (5 μg/ml) or dibutyryl cyclic AMP (10 -4 M), which is an intracellular signaling factor that can cause a significant increase in the enzyme activity. Mitochondrial regucalcin localization was significantly increased in the heart of regucalcin transgenic rats as compared with that of normal rats using Western blot analysis. Ca 2+ -ATPase activity was significantly increased in the heart mitochondria of regucalcin transgenic rats. This study demonstrates that regucalcin has an activating effect on Ca 2+ -ATPase in rat heart mitochondria, suggesting its role in the regulation of heart mitochondrial function.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Regucalcin increases Ca2+-ATPase activity in the heart mitochondria of normal and regucalcin transgenic rats

Akhter

Sawada²,

Yamaguchi³

2006

Int J Mol Med

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Regucalcin Regulates Ca 2+ Signaling-dmentioning

confidence: 99%

“…The role of regucalcin in the regulation of protein phosphatase activity in the heart muscle cytosol was demonstrated using regucalcin TG rats ( 35 ). Protein phosphatase activity was assayed in a reaction mixture containing the cytosolic protein in the presence of phosphotyrosine, phosphoserine and phosphothreonine ( 35 ). The addition of CaCl 2 (10 and 20 μM) to the enzyme reaction mixture led to an increase in protein phosphatase activity towards three phosphoaminoacids ( 35 ).…”

Section: Regucalcin Regulates Ca 2+ Signaling-dmentioning

confidence: 99%

Regulatory role of regucalcin in heart calcium signaling: Insight into cardiac failure (Review)

Yamaguchi

2014

Biomedical Reports

Self Cite

View full text Add to dashboard Cite

Regucalcin was first identified in 1978 as a regulatory protein of Ca2+ signaling in liver cells. Regucalcin was shown to play a multifunctional role in cell regulation, such as maintainance of intracellular Ca2+ homeostasis and suppression of signal transduction, protein synthesis, nuclear function, cell proliferation and apoptosis in various types of cells and tissues. Cardiac excitation-contraction coupling is based on the regulation of intracellular Ca2+ concentration by the Ca2+ pump in the sarcoplasmic reticulum of heart muscle cells. Regucalcin, which is expressed in the heart, was found to increase rat heart sarcoplasmic reticulum Ca2+-ATPase activity and ATP-dependent Ca2+ uptake and mitochondrial Ca2+-ATPase activity. Regucalcin was also shown to suppress Ca2+-dependent protein tyrosine phosphatase, Ca2+/calmodulin-dependent protein phosphatase (calcineurin) and nitric oxide (NO) synthase activity in the heart cytoplasm. Moreover, regucalcin was found to activate superoxide dismutase (SOD), which plays a significant role in the prevention of cell death and apoptosis in the heart. Regucalcin may be a key molecule in heart muscle cell regulation through Ca2+ signaling. Regucalcin may also play a pathophysiological role in heart failure. The aim of this study was to review the recent findings regarding the role of regucalcin in Ca2+ signaling in the heart.

show abstract

“…Recently, it has been shown that regucalcin can activate Ca 2+ -ATPase, which has a role as a Ca 2+ pump, in rat heart microsomes (12) and mitochondria (20), indicating that regucalcin plays a role in the regulation of Ca 2+ homeostasis in heart cells. Moreover, regucalcin has been demonstrated to regulate the activities of nitric oxide synthase (21), protein phosphatase (22), and superoxide dismutase (23), which is related to intracellular signaling, in rat heart cytosol. Regucalcin may play a role in the regulation of the heart function.…”

Section: Introductionmentioning

confidence: 99%

Suppression of regucalcin mRNA expression in the hearts of rats administered with free radical compound: The administration-induced death is accelerated in regucalcin transgenic rats

Akhter

Nakagawa²,

Kobayashi³

et al. 2007

Int J Mol Med

Self Cite

View full text Add to dashboard Cite

Abstract. The expression of regucalcin, a regulatory protein in the intracellular signaling system, in the hearts of rats was investigated. Regucalcin expression was examined using reverse transcription-polymerase chain reaction and Western blot analysis. Regucalcin mRNA and its protein levels in the hearts of male and female rats were significantly decreased with increasing age (50 weeks old) as compared with that of 5-week-old rats. The effect of 1,1-diphenyl-2-picryl-hydrazyl (DPPH), a compound that produces free radical, on regucalcin mRNA expression in the hearts of female rats (5 weeks old) was examined. Heart regucalcin mRNA levels were significantly decreased at 60 or 180 min after a single intraperitoneal administration of DPPH (0.5 mg /100 g body weight), suggesting that free radical stress has a suppressive effect on the gene expression. Normal (wild) female rats died at approximately 300 min after a single intraperitoneal administration of DPPH (0.5 mg/100 g), while regucalcin transgenic (TG) female rats died at approximately 150 min after the administration. Heart regucalcin protein in DPPHadministered rats was greater in regucalcin TG rats than in normal (wild) rats. This study demonstrates that the death of regucalcin TG rats is accelerated after the administration of free radical compound, indicating that overexpression of regucalcin does not have effects as the suppressor for free radical stress and the scavenger for free radical in rats.

show abstract

Suppressive effect of regucalcin on protein phosphatase activity in the heart cytosol of normal and regucalcin transgenic rats

Cited by 3 publications

References 0 publications

Regucalcin increases Ca2+-ATPase activity in the heart mitochondria of normal and regucalcin transgenic rats

Regucalcin increases Ca2+-ATPase activity in the heart mitochondria of normal and regucalcin transgenic rats

Regulatory role of regucalcin in heart calcium signaling: Insight into cardiac failure (Review)

Suppression of regucalcin mRNA expression in the hearts of rats administered with free radical compound: The administration-induced death is accelerated in regucalcin transgenic rats

Contact Info

Product

Resources

About