Insertion of a SNS-specific tetrapeptide in S3-S4 linker of D4 accelerates recovery from inactivation of skeletal muscle voltage-gated Na channel μ1 in HEK293 cells

S. D. Dib-Hajj, K. Ishikawa, T. R. Cummins, S. G. Waxman

Research output: Contribution to journalArticle

42 Scopus citations


Na channel subunits αSNS (PN3) and αμ1(SkM1) produce slowly inactivating/TTX-resistant and rapidly inactivating/TTX-sensitive currents, respectively. αSNS (PN3) current recovers from inactivation (reprimes) rapidly. Sequence alignment identified the tetrapeptide SLEN, in the S3-S4 linker of D4, as αSNS-specific. To determine whether SLEN endows Na channels with slow kinetics and/or rapid repriming, we analyzed the transient Na current produced by a chimera μ1SLEN in HEK293 cells. Neither kinetics nor voltage dependence of activation and inactivation was affected. However, repriming was twice as fast as in the wild type at -100 mV. This suggests that SLEN may contribute to the rapid repriming of TTX-resistant Na current.

Original languageEnglish (US)
Pages (from-to)11-14
Number of pages4
JournalFEBS Letters
Issue number1
StatePublished - Oct 13 1997



  • Channel repriming
  • Na current kinetics
  • TTX
  • Voltage dependence

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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