Channelosome and intracellular K+ channels in arrhythmia

Mutations in Kir2.1 resulting in defects in trafficking to the cardiomyocyte sarcolemma promote arrhythmia in Anderson-Tawil syndrome. Macias and colleagues provide a dual mechanism underlying cardiac arrhythmia that involves chaperoning of voltage-gated Na+ channels and a unique population of intracellular Kir2.1 channels that regulate Ca2+ cycling at the sarcoplasmic reticulum.