Long-term inactivation particle for voltage-gated sodium channels

Katarzyna Dover, Sergio Solinas, Egidio D'Angelo, Mitchell Goldfarb

Research output: Contribution to journalArticle

Abstract

Action potential generation is governed by the opening, inactivation, and recovery of voltage-gated sodium channels. A channel's voltage-sensing and pore-forming α subunit bears an intrinsic fast inactivation particle that mediates both onset of inactivation upon membrane depolarization and rapid recovery upon repolarization. We describe here a novel inactivation particle housed within an accessory channel subunit (A-type FHF protein) that mediates rapid-onset, long-term inactivation of several sodium channels. The channel-intrinsic and tethered FHF-derived particles, both situated at the cytoplasmic face of the plasma membrane, compete for induction of inactivation, causing channels to progressively accumulate into the long-term refractory state during multiple cycles of membrane depolarization. Intracellular injection of a short peptide corresponding to the FHF particle can reproduce channel long-term inactivation in a dose-dependent manner and can inhibit repetitive firing of cerebellar granule neurons. We discuss potential structural mechanisms of long-term inactivation and potential roles of A-type FHFs in the modulation of action potential generation and conduction.

Original languageEnglish
Pages (from-to)3695-3711
Number of pages17
JournalJournal of Physiology
Volume588
Issue number19
DOIs
Publication statusPublished - Oct 2010

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ASJC Scopus subject areas

  • Physiology

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