Kvbeta subunits increase expression of Kv4.3 channels by interacting with their C termini.

Auxiliary Kvbeta 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 Kvbeta2 subunits in the brain. Expression of Kvbeta1 or Kvbeta2 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 Kvbeta-associated channel proteins are more stable than those without the auxiliary subunits. This association between Kv4.3 and Kvbeta subunits requires the C terminus but not the N terminus of the channel polypeptide. Thus, Kvbeta subunits utilize diverse molecular interactions to stimulate the expression of Kv channels from different families.