Kvβ Subunits Increase Expression of Kv4.3 Channels by Interacting with Their C Termini

Abstract

Auxiliary Kvβ subunits form complexes with Kv1 family voltage-gated K+ channels by binding to a part of the N terminus of channel polypeptide. This association influences expression and gating of these channels. Here we show that Kv4.3 proteins are associated with Kvβ2 subunits in the brain. Expression of Kvβ1 or Kvβ2 subunits does not affect Kv4.3 channel gating but increases current density and protein expression. The increase in Kv4.3 protein is larger at longer times after transfection, suggesting that Kvβ-associated channel proteins are more stable than those without the auxiliary subunits. This association between Kv4. 3 and Kvβ subunits requires the C terminus but not the N terminus of the channel polypeptide. Thus, Kvβ subunits utilize diverse molecular interactions to stimulate the expression of Kv channels from different families.