What question did this study set out to answer?

To clone and characterize mouse ether-a-go-go-related gene (Merg1) isoforms and determine how their interactions shape cardiac delayed rectifier potassium currents.

November 1, 1997Circulation Research

Two Isoforms of the MouseEther-a-go-go–Related Gene Coassemble to Form Channels With Properties Similar to the Rapidly Activating Component of the Cardiac Delayed Rectifier K+Current

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Population

Mouse genomic and cardiac cDNA libraries, and Xenopus oocytes for heterologous expression

Comparison

Cloning and heterologous expression of Merg1… vs HERG and individual Merg1 isoforms

Design

Preclinical

Authors

BLBarry LondonElectrophysiology MTMatthew C. TrudeauUniversity of Maryland, Baltimore KNKimberly P. NewtonUniversity of California, San Diego

Discussion

Member takes

Implication

May refine IKr molecular models in animals; leaves open human relevance for Long-QT pathogenesis.

Key Points

To clone and characterize mouse ether-a-go-go-related gene (Merg1) isoforms and determine how their interactions shape cardiac delayed rectifier potassium currents.
Cloned Merg1 from mouse genomic and cardiac cDNA libraries and mapped its chromosomal localization relative to human HERG.
Identified tissue-specific expression patterns of Merg1 splice variants across mouse cardiac, neural, and other tissues.
Expressed Merg1 isoforms individually and together in Xenopus oocytes to analyze E-4031 drug sensitivity and deactivation kinetics.
Identified three Merg1 isoforms from a 16-exon gene on mouse chromosome 5, including Merg1b, a heart-specific variant with an abbreviated N-terminal domain.
Merg1a and HERG generated inwardly rectifying currents with slow deactivation, whereas Merg1b and Merg1a' exhibited rapid deactivation kinetics.
Coassembly of Merg1a and Merg1b in Xenopus oocytes reconstituted channels with accelerated deactivation kinetics nearly identical to the native cardiac IKr current.

Structured PICO

Population

Mouse genomic and cardiac cDNA libraries, and Xenopus oocytes for heterologous expression

Intervention

Cloning and heterologous expression of Merg1 isoforms (Merg1a, Merg1a', Merg1b)

Comparator

HERG and individual Merg1 isoforms

Outcome

Electrophysiological properties of K+ currents (deactivation kinetics, inward rectification, E-4031 sensitivity)surrogate

The identification of a novel N-terminal Erg isoform (Merg1b) that coassembles with Merg1a to produce currents resembling cardiac IKr provides insight into the molecular basis of IKr and the potential pathogenesis of Long-QT syndrome.

Cite This Study

London et al. (1997) studied this question.

synapsesocial.com/papers/6a178bd65fdf2a7b88aa1f9e https://doi.org/10.1161/01.res.81.5.870

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Two Isoforms of the MouseEther-a-go-go–Related Gene Coassemble to Form Channels With Properties Similar to the Rapidly Activating Component of the Cardiac Delayed Rectifier K+Current

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Two Isoforms of the MouseEther-a-go-go–Related Gene Coassemble to Form Channels With Properties Similar to the Rapidly Activating Component of the Cardiac Delayed Rectifier K+Current

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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