The newly synthesized selective Ca2+calmodulin dependent protein kinase II inhibitor KN-93 reduces dopamine contents in PC12h cells

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Abstract

We reported that one of the isoquinolinesulfonamide derivatives, KN-62, is a potent and specific inhibitor of Ca2+calmodulin-dependent protein kinase II (CaMKII) (Tokumitsu, H., Chijiwa, T., Hagiwara, M., Mizutani, A., Terasawa, M. and Hidaka, H. (1990) J. Biol. Chem. 265, 4315–4320). We have now investigated the inhibitory property of a newly synthesized methoxybenzenesulfonamide, KN-93, on CaMKII activity in situ and in vitro. KN-93 elicited potent inhibitory effects on CaMKII phosphorylating activity with an inhibition constant of 0.37 μM but this compound had no significant effects on the catalytic activity of cAMP-dependent protein kinase, Ca2+phospholipid dependent protein kinase, myosin light chain kinase and Ca2+-phosphodiesterase. KN-93 also inhibited the auto-phosphorylation of both the α- and β-subunits of CaMKII. Kinetic analysis indicated that KN-93 inhibits CaMKII, in a competitive fashion against calmodulin. To evaluate the regulatory role of CaMKII on catecholamine metabolism, we examined the effect of KN-93 on dopamine (DA) levels in PC12h cells. The DA levels decreased in the presence of KN-93. Further, the tyrosine hydroxylase (TH) phosphorylation induced by KCl or acetylcholine was significantly suppressed by KN-93 in PC12h cells while events induced by forskolin or 8-Br-cAMP were not affected. These results suggest that KN-93 inhibits DA formation by modulating the reaction rate of TH to reduce the Ca2+-mediated phosphorylation levels of the TH molecule.

References (32)

  • H. Tokumitsu et al.

    J. Biol. Chem

    (1990)
  • T. Yamauchi et al.

    J. Biol. Chem

    (1981)
  • T. Nagatsu et al.

    J. Biol. Chem

    (1964)
  • M. McTigue et al.

    J. Biol. Chem

    (1985)
  • J.W. Haycock

    J. Biol. Chem

    (1990)
  • J.W. Haycock et al.

    J. Biol. Chem

    (1991)
  • A. Ishii et al.

    Biochem. Biophys. Res. Commun

    (1991)
  • T. Yamauchi et al.

    FEBS Lett

    (1980)
  • R.S. Adelstein et al.

    J. Biol. Chem

    (1981)
  • T. Endo et al.

    J. Biol. Chem

    (1981)
  • J.A. Beavo et al.

    Methods Enzymol

    (1974)
  • H. Hidaka et al.

    Methods Enzymol

    (1987)
  • H. Hidaka et al.

    Biochem. Med

    (1974)
  • Y. Hashimoto et al.

    Arch. Biochem. Biophys

    (1987)
  • K. Kiuchi et al.

    Neurosci. Lett

    (1988)
  • M.M. Bradford

    Anal. Biochem

    (1976)
  • Cited by (0)

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