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Role of protein phosphorylation in regulation of brainL-glutamate decarboxylase activity

  • Original Paper
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Journal of Biomedical Science

Abstract

In the brain, the γ-aminobutyric acid (GABA) level is primarily controlled by the activity of its synthesizing enzyme,L-glutamate decarboxylase (GAD). At present, mechanisms responsible for regulation of GAD activity remain largely unknown. Here we report that GAD activity is inhibited by conditions favoring protein phosphorylation, and this inhibition can be reversed by phosphatase treatment. Furthermore, this inhibition appears to result from the suppression of a Ca2+-dependent phosphatase. Phosphorylation of GAD is demonstrated by direct incorporation of32P into the GAD protein. These results suggest that GAD activity in the brain is inhibited by phosphorylation and activated by dephosphorylation. A model for regulation of GABA synthesis related to neuronal excitation is discussed.

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References

  1. Ames M, Lerner P, Lovenberg W. Tyrosine hydroxylase: Activation by protein phosphorylation and end product inhibition. J Biol Chem 253:27–31;1978.

    PubMed  Google Scholar 

  2. Arias C, Valero H, Tapia R. Inhibition of brain glutamate decarboxylase activity is related to febrile seizures in rat pups. J Neurochem 58:369–373;1992.

    PubMed  Google Scholar 

  3. Baekkeskov S, Aanstoot HJ, Christgau S, Reetz A, Solimena M, Cascalho M, Folli F, Richter-Olsen H, Decamilli P. Identification of the 64 K autoantigen in insulin-dependent diabetes as the GABA-synthesizing enzyme glutamic acid decarboxylase. Nature 347:151–156;1990.

    Article  PubMed  Google Scholar 

  4. Blum P, Jankovic J. Stiff-person syndrome: An autoimmune disease. Mov Disord 6:12–20;1991.

    Article  PubMed  Google Scholar 

  5. Bradford MM. A rapid sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254;1976.

    PubMed  Google Scholar 

  6. Brooks MW, Clark JM. Enhancement of norepinephrine release from rat brain synaptosomes by alpha cyano pyrethroids. Pestic Biochem Physiol 28:127–139;1987.

    Article  Google Scholar 

  7. Bu DF, Erlander MG, Hitz BC, Tillakaratne NJK, Kaufman DL, Wagner-McPherson CB, Evans GA, Tobin AJ. Two human glutamate decarboxylase, 65-kDa GAD and 67-kDa GAD, are each encoded by a single gene. Proc Natl Acad Sci USA 89:2115–2119;1992.

    PubMed  Google Scholar 

  8. Denner LA, Wei SC, Lin HS, Lin CT, Wu JY. BrainL-glutamate decarboxylase: Purification and subunit structure. Proc Natl Acad Sci USA 84:668–672;1987.

    PubMed  Google Scholar 

  9. Enan E, Matsumura F. Specific inhibition of calcineurin by type II synthetic pyrethroid insecticides. Biochem Pharmacol 43:1777–1784;1992.

    Article  PubMed  Google Scholar 

  10. Erlander MG, Tobin AJ. The structural and functional heterogeneity of glutamic acid decarboxylase: A review. Neurochem Res 16:215–226;1991.

    Article  PubMed  Google Scholar 

  11. Fernley HN, Walker PG. Studies on alkaline phosphatase. J Biochem 104:1011–1024;1967.

    Google Scholar 

  12. Huang WM, Reed-Fourquet L, Wu E, Wu JY. Molecular cloning and amino acid sequence of brainL-glutamate decarboxylase. Proc Natl Acad Sci USA 87:8491–8495;1990.

    PubMed  Google Scholar 

  13. Hunter T. Protein kinase classification. Methods Enzymol 200:3–37;1991.

    PubMed  Google Scholar 

  14. Kuhn DM, O'Callaghan JP, Juskevich J, Lovenberg W. Activation of brain tryptophan hydroxylase by ATP-Mg2+: Dependence on calmodulin. Proc Natl Acad Sci USA 77:4688–4691;1980.

    PubMed  Google Scholar 

  15. Lineweaver H, Burk D. Determination of enzyme dissociation constants. J Am Chem Soc 56:658–666;1934.

    Article  Google Scholar 

  16. Martin DL, Rimvall K. Regulation of γ-aminobutyric acid synthesis in the brain. J Neurochem 60:395–407;1993.

    PubMed  Google Scholar 

  17. Miller LP, Martin DL, Walters JR. Post-mortem changes implicate adenine nucleotides and pyridoxal-5′-phosphate in regulation of brain glutamate decarboxylase. Nature 266:847–848;1977.

    Article  PubMed  Google Scholar 

  18. Miller LP, Walters JR. Effects of depolarization on cofactor regulation of glutamic acid decarboxylase in substantia nigra synaptosomes. J Neurochem 33:533–539;1979.

    PubMed  Google Scholar 

  19. Nathan B, Bao J, Hsu CC, Aguilar P, Wu R, Yarom M, Wu JY. A novel form of brainL-glutamate decarboxylase — Identification, isolation and its relation to insulin dependent diabetes mellitus. Proc Natl Acad Sci USA 91:242–246;1994.

    PubMed  Google Scholar 

  20. Pearson RB, Kemp BE. Protein kinase phosphorylation site sequences and consensus specificity motif: Tabulations. Methods Enzymol 200:63–81;1991.

    Google Scholar 

  21. Roberts E. GABA in nervous system function — An overview. In: Tower DB ed. The Nervous System: The Basic Neuroscience. New York, Raven, 541–552;1975.

    Google Scholar 

  22. Roberts E, Kuriyama K. Biochemical-physiological correlation in studies of the γ-aminobutyric acid system. Brain Res 8:1–35;1968.

    Article  PubMed  Google Scholar 

  23. Seligmann B, Miller LP, Brockman DE, Martin DL. Studies on the regulation of GABA synthesis: The interaction of adenine nucleotides and glutamate with brain glutamate decarboxylase. J Neurochem 30:371–376;1978.

    PubMed  Google Scholar 

  24. Shenolikar S, Nairn AC. Protein phosphatases: Recent progress. Adv Second Messenger Phosphoprotein Res 23:1–121;1991.

    PubMed  Google Scholar 

  25. Sherman AD, Davison AT, Baruah S, Hegwood TS, Waziri R. Evidence of glutamatergic deficiency in schizophrenia. Neurosci Lett 121:77–80;1991.

    Article  PubMed  Google Scholar 

  26. Ubbink JB, Bissbort S, Vermaak WJH, Delport R. Inhibition of pyridoxal kinase by methylxanthines. Enzyme 43:72–79, 1990.

    PubMed  Google Scholar 

  27. Wary W, Boulikas T, Wary VP, Hancock R. Silver staining of proteins in polyacrylamide gels. Anal Biochem 118:197–203;1981.

    Article  PubMed  Google Scholar 

  28. Wu JY. Purification, characterization and kinetic studies of GAD and GABA-T from mouse brain. In: Roberts E, Chase TN, Tower DB, eds. GABA in Nervous System Function. New York, Raven, 7–60;1976.

    Google Scholar 

  29. Wu JY, Denner LA, Wei SC, Lin CT, Song GX, Xu YF, Liu JW, Lin HS. Production and characterization of polyclonal and monoclonal antibodies to rat brainL-glutamate decarboxylase. Brain Res 373:1–14;1986.

    Article  PubMed  Google Scholar 

  30. Wu JY, Roberts E. Properties of brainL-glutamate decarboxylase: Inhibition studies. J Neurochem 23:759–767;1974.

    PubMed  Google Scholar 

  31. Wu JY, Su YYT, Lam DMK, Schousboe A, Chude O. Assay methods, purification and characterization ofL-glutamate decarboxylase and GABA-transaminase. Res Methods Neurochem 5:129–177;1981.

    Google Scholar 

  32. Yarom M, Bao J, Tang XW, Wu E, Lee YH, Tsai WH, Wu JY. Isolation and characterization of endogenous modulators for GABA system. Neurochem Res 17:107–114;1992.

    Article  PubMed  Google Scholar 

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Authors and Affiliations

  1. Department of Physiology and Cell Biology, University of Kansas, 66045, Lawrence, KS, USA

    Jun Bao, Britto Nathan, Che-Chang Hsu, Yuan Zhang, Rosemary Wu & Jang-Yen Wu

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  1. Jun Bao
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  2. Britto Nathan
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  3. Che-Chang Hsu
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  4. Yuan Zhang
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  5. Rosemary Wu
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Bao, J., Nathan, B., Hsu, CC. et al. Role of protein phosphorylation in regulation of brainL-glutamate decarboxylase activity. J Biomed Sci 1, 237–244 (1994). https://doi.org/10.1007/BF02253308

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  • DOI: https://doi.org/10.1007/BF02253308

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