Suppressive effect of endogenous regucalcin on protein tyrosine phosphatase activity in the nucleus of rat brain: Attenuation with increasing age

  • Authors:
    • Minako Tobisawa
    • Masayoshi Yamaguchi
  • View Affiliations

  • Published online on: February 1, 2003     https://doi.org/10.3892/ijmm.11.2.205
  • Pages: 205-210
Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Abstract

The effect of endogenous regucalcin, which is a regulatory protein of Ca2+ signaling, on protein tyrosine phosphatase activity in the nucleus of brain tissues of young and aged rats was investigated. Phosphotyrosine was used as the substrate for assay of protein tyrosine phosphatase activity. Protein tyrosine phosphatase activity in the brain nucleus of young (5 weeks old) rats was significantly increased in the presence of calcium chloride (5-50 µM) in the enzyme reaction mixture. The increase was completely blocked by the addition of trifluoperazine (10-50 µM), an antagonist of calmodulin, indicating that the enzyme is activated by endogenous Ca2+/ calmodulin. The addition of regucalcin (10−4-10−8 M) in the enzyme reaction mixture caused a significant decrease in protein tyrosine phosphatase activity in the absence or presence of calcium chloride (20 µM). Brain nuclear protein tyrosine phosphatase activity was significantly raised in the presence of anti-regucalcin monoclonal antibody (10-50 ng/ml) in the enzyme reaction mixture. The increase was completely prevented by the addition of regucalcin (10−6 M). In the brain nucleus of aged (50 weeks old) rats, protein tyrosine phosphatase activity was elevated significantly as compared with that of 5 weeks old rats. The effect of anti-regucalcin monoclonal antibody in increasing the enzyme activity in the brain nucleus of aged rats was seen in the presence of 50 ng/ml of the antibody. Such an effect was not found by the antibody of 10 and 25 ng/ml. Regucalcin protein in brain nucleus was detected by Western blot analysis. This level was significantly decreased by increasing age. The present study demonstrates that endogenous regucalcin plays a suppressive role in the regulation of protein tyrosine phosphatase activity in the nucleus of rat brain, and that this regulation is attenuated with increasing age.

Related Articles

Journal Cover

February 2003
Volume 11 Issue 2

Print ISSN: 1107-3756
Online ISSN:1791-244X

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
x
Spandidos Publications style
Tobisawa M and Tobisawa M: Suppressive effect of endogenous regucalcin on protein tyrosine phosphatase activity in the nucleus of rat brain: Attenuation with increasing age. Int J Mol Med 11: 205-210, 2003
APA
Tobisawa, M., & Tobisawa, M. (2003). Suppressive effect of endogenous regucalcin on protein tyrosine phosphatase activity in the nucleus of rat brain: Attenuation with increasing age. International Journal of Molecular Medicine, 11, 205-210. https://doi.org/10.3892/ijmm.11.2.205
MLA
Tobisawa, M., Yamaguchi, M."Suppressive effect of endogenous regucalcin on protein tyrosine phosphatase activity in the nucleus of rat brain: Attenuation with increasing age". International Journal of Molecular Medicine 11.2 (2003): 205-210.
Chicago
Tobisawa, M., Yamaguchi, M."Suppressive effect of endogenous regucalcin on protein tyrosine phosphatase activity in the nucleus of rat brain: Attenuation with increasing age". International Journal of Molecular Medicine 11, no. 2 (2003): 205-210. https://doi.org/10.3892/ijmm.11.2.205