Functional evolution of Erg potassium channel gating reveals an ancient origin for IKr.

ABSTRACT: Mammalian Ether-a-go-go related gene (Erg) family voltage-gated K(+) channels possess an unusual gating phenotype that specializes them for a role in delayed repolarization. Mammalian Erg currents rectify during depolarization due to rapid, voltage-dependent inactivation, but rebound during repolarization due to a combination of rapid recovery from inactivation and slow deactivation. This is exemplified by the mammalian Erg1 channel, which is responsible for IKr, a current that repolarizes cardiac action potential plateaus. The Drosophila Erg channel does not inactivate and closes rapidly upon repolarization. The dramatically different properties observed in mammalian and Drosophila Erg homologs bring into question the evolutionary origins of distinct Erg K(+) channel functions. Erg channe

SUBMITTER: Martinson AS 

PROVIDER: S-EPMC3992637 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature