Yang E K, Alvira M R, Levitan E S, Takimoto K
Department of Pharmacology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
J Biol Chem. 2001 Feb 16;276(7):4839-44. doi: 10.1074/jbc.M004768200. Epub 2000 Nov 21.
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.
辅助性Kvβ亚基通过与通道多肽N端的一部分结合，与Kv1家族电压门控钾通道形成复合物。这种结合会影响这些通道的表达和门控。在这里，我们表明Kv4.3蛋白在大脑中与Kvβ2亚基相关联。Kvβ1或Kvβ2亚基的表达不影响Kv4.3通道的门控，但会增加电流密度和蛋白表达。转染后较长时间，Kv4.3蛋白的增加幅度更大，这表明与Kvβ相关的通道蛋白比没有辅助亚基的通道蛋白更稳定。Kv4.3与Kvβ亚基之间的这种结合需要通道多肽的C端而非N端。因此，Kvβ亚基利用多种分子相互作用来刺激不同家族Kv通道的表达。
