Gating consequences of charge neutralization of arginine residues in the S4 segment of K(v)7.2, an epilepsy-linked K+ channel subunit.

ABSTRACT: The K(v)7.2 subunits are the main molecular determinants of the M-current, a widespread K(+) current regulating neuronal excitability. Mutations in the K(v)7.2 gene cause benign familial neonatal seizures, an autosomally inherited human epilepsy. The benign familial neonatal seizure-causing mutations include those at arginine residues at positions 207 and 214 in the S(4) segment of K(v)7.2. In this study, each of the six S(4) arginines was individually replaced with neutral glutamines, and the functional properties of mutant channels were studied by whole-cell and single-channel voltage-clamp measurements. The results obtained suggest that each S(4) arginine residue plays a relevant role in the voltage-dependent gating of K(v)7.2 channels. In particular, a decreased positive charge at the

SUBMITTER: Miceli F 

PROVIDER: S-EPMC2517032 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature