Publications by authors named "Jane A Bursill"

Objectives: This study sought to evaluate mutations in genes encoding the slow component of the cardiac delayed rectifier K+ current (I(Ks)) channel in familial atrial fibrillation (AF).

Background: Although AF can have a genetic etiology, links between inherited gene defects and acquired factors such as atrial stretch have not been explored.

Methods: Mutation screening of the KCNQ1, KCNE1, KCNE2, and KCNE3 genes was performed in 50 families with AF.

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The function of voltage-gated human ether-à-go-go related gene (hERG) K(+) channels is critical for both normal cardiac repolarization and suppression of arrhythmias initiated by premature excitation. These important functions are facilitated by their unusual kinetics that combine relatively slow activation and deactivation with rapid and voltage-dependent inactivation and recovery from inactivation. The thermodynamics of these unusual features were examined by exploring the effect of temperature on the activation and inactivation processes of hERG channels expressed in Chinese hamster ovary cells.

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The HERG K+ channel has very unusual kinetic behavior that includes slow activation but rapid inactivation. These features are critical for normal cardiac repolarization as well as in preventing lethal ventricular arrhythmias. Mutagenesis studies have shown that the extracellular peptide linker joining the fifth transmembrane domain to the pore helix is critical for rapid inactivation of the HERG K+ channel.

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The three-dimensional structure of chemically synthesized CnErg1 (Ergtoxin), which specifically blocks HERG (human ether-a-go-go-related gene) K+ channels, was determined by nuclear magnetic resonance spectroscopy. CnErg1 consists of a triple-stranded beta-sheet and an alpha-helix, as is typical of K+ channel scorpion toxins. The peptide structure differs from the canonical structures in that the first beta-strand is shorter and is nearer to the second beta-strand rather than to the third beta-strand on the C-terminus.

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