Non-native R1 substitution in the s4 domain uniquely alters Kv4.3 channel gating.

ABSTRACT: The S4 transmembrane domain in Shaker (Kv1) voltage-sensitive potassium channels has four basic residues (R1-R4) that are responsible for carrying the majority of gating charge. In Kv4 channels, however, R1 is replaced by a neutral valine at position 287. Among other differences, Kv4 channels display prominent closed state inactivation, a mechanism which is minimal in Shaker. To determine if the absence of R1 is responsible for important variation in gating characteristics between the two channel types, we introduced the V287R mutant into Kv4.3 and analyzed its effects on several voltage sensitive gating transitions. We found that the mutant increased the voltage sensitivity of steady-state activation and altered the kinetics of activation and deactivation processes. Although the kinetics

SUBMITTER: Skerritt MR 

PROVIDER: S-EPMC2582947 | biostudies-literature | 2008

REPOSITORIES: biostudies-literature