Auto-inhibition of Ca2+/calmodulin-dependent protein kinase II by its ATP-binding domain

I. Lengyel, A. C. Nairn, A. McCluskey, G. Tóth, B. Penke, J. A.P. Rostas

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Ca2+/calmodulin dependent protein kinase (CaMPK) II is a key enzyme in many physiological processes. The enzyme is inactive unless Ca2+/CaM binds to it. In this inactive form CaMPK-II does not bind ATP suggesting that the ATP-binding domain is involved in an intramolecular interaction. We show here that F12, a 12 amino acid long peptide fragment of the ATP-binding domain (CaMPK-II23-34, GAFSVVRRCVKV) can inhibit the Ca2+/CaM-dependent activity (IC50 of 3 μM) but has no effect on the Ca2+/CaM-independent activity of CaMPK-II. Kinetic analysis exhibited mixed inhibition with respect to autocamtide-2 and ATP. The inhibition by F12 showed specificity towards CaMPK-II, but also inhibited CaMPK-I (IC50 = 12.5 μM), while CaMPK-IV (IC50 = 85 μM) was inhibited poorly and cAMP-dependent protein kinase (PKA) was not inhibited. Substitution of phenylalanine at position 25 to alanine (A12), had little effect on the inhibition of different Ca2+/CaM-dependent protein kinases, suggesting that phenylalanine 25 does not play a crucial role in the interactions involving F12. Thus the molecular interactions involving the ATP-binding domain appears to play a role in the regulation of nonphosphorylated CaMPK-II activity.

Original languageEnglish
Pages (from-to)1066-1072
Number of pages7
JournalJournal of neurochemistry
Volume76
Issue number4
DOIs
Publication statusPublished - Mar 3 2001

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Keywords

  • ATP-binding domain
  • Autonomous activity
  • Autophosphorylation
  • Calcium/calmodulin
  • Calcium/calmodulin-stimulated protein kinase
  • Intra-molecular interaction

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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