Modulation of Drosophila Slowpoke Calcium-Dependent Potassium Channel Activity by Bound Protein Kinase A Catalytic Subunit

Yi Zhou, Jing Wang, Hua Wen, Olga Kucherovsky, Irwin B. Levitan

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

Drosophila Slowpoke (dSlo) calcium-dependent potassium channels bind directly to the catalytic subunit of cAMP-dependent protein kinase (PKAc). We demonstrate here that coexpression of PKAc with dSlo in mammalian cells results in a dramatic decrease of dSlo channel activity. This modulation requires catalytically active PKAc but is not mediated by phosphorylation of S942, the only PKA consensus site in the dSlo C-terminal domain. dSlo binds to free PKAc but not to the PKA holoenzyme that includes regulatory subunits and is inactive. Activators of endogenous PKA that stimulate dSlo phosphorylation, but do not produce detectable PKAc binding to dSlo, do not modulate channel function. Furthermore, the catalytically inactive PKAc mutant does bind to dSlo but does not modulate channel activity. These results are consistent with the hypothesis that both binding of active PKAc to dSlo and phosphorylation of dSlo or some other protein are necessary for channel modulation.

Original languageEnglish (US)
Pages (from-to)3855-3863
Number of pages9
JournalJournal of Neuroscience
Volume22
Issue number10
DOIs
StatePublished - May 15 2002

Keywords

  • Ca-dependent K channel
  • Modulation
  • Phosphorylation
  • Protein-protein interaction
  • Whole-cell recording
  • cAMP-dependent protein kinase
  • dSlo

ASJC Scopus subject areas

  • Neuroscience(all)

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