KvLQT1, a voltage-gated potassium channel responsible for human cardiac arrhythmias

Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):4017-21. doi: 10.1073/pnas.94.8.4017.

Abstract

The clinical features of long QT syndrome result from episodic life-threatening cardiac arrhythmias, specifically the polymorphic ventricular tachycardia torsades de pointes. KVLQT1 has been established as the human chromosome 11-linked gene responsible for more than 50% of inherited long QT syndrome. Here we describe the cloning of a full-length KVLQT1 cDNA and its functional expression. KVLQT1 encodes a 676-amino acid polypeptide with structural characteristics similar to voltage-gated potassium channels. Expression of KvLQT1 in Xenopus oocytes and in human embryonic kidney cells elicits a rapidly activating, K+-selective outward current. The I(Kr)-specific blockers, E-4031 and dofetilide, do not inhibit KvLQT1, whereas clofilium, a class III antiarrhythmic agent with the propensity to induce torsades de pointes, substantially inhibits the current. Elevation of cAMP levels in oocytes nearly doubles the amplitude of KvLQT1 currents. Coexpression of minK with KvLQT1 results in a conductance with pharmacological and biophysical properties more similar to I(Ks) than other known delayed rectifier K+ currents in the heart.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • Gene Expression
  • Heart / physiopathology*
  • Humans
  • KCNQ Potassium Channels
  • KCNQ1 Potassium Channel
  • Molecular Sequence Data
  • Potassium Channels / isolation & purification
  • Potassium Channels / physiology*
  • Potassium Channels, Voltage-Gated*
  • Tachycardia, Ventricular / physiopathology*
  • Xenopus

Substances

  • KCNQ Potassium Channels
  • KCNQ1 Potassium Channel
  • KCNQ1 protein, human
  • Potassium Channels
  • Potassium Channels, Voltage-Gated

Associated data

  • GENBANK/U86146