Differential association of the auxiliary subunit Kvβ2 with Kv1.4 and Kv4.3 K+ channels

FEBS Letters

Levitan, Edwin S²  Wang, Lin²  Takimoto, Koichi¹ 

[1] Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15261, USA;Department of Pharmacology, University of Pittsburgh, Pittsburgh, PA 15261, USA

关键词: Potassium channel;    Ancillary subunit;    Subunit assembly;    Channel biogenesis;    T1 domain;   

DOI  :  10.1016/S0014-5793(03)00705-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Kvβ2 subunits associate with Kv1 and Kv4 K⁺ channels, but the basis of preferential association is not understood. For example, detergent resistance suggests stronger auxiliary subunit association with Kv4.2 than with Kv1.2, but Kvβ2 preferentially localizes with the latter channels in brain. Here we examine the interaction of Kvβ2 with two native binding partners in brain: Kv4.3 and Kv1.4. We show that the auxiliary subunit binds more efficiently to Kv1.4 than to Kv4.3 in mammalian cells. However, preexisting Kvβ2 complexes with Kv1.4 and Kv4.3 have similar detergent sensitivity. Thus, preferential steady state binding may reflect a difference in initial association rather than stability. We also find that that the cytoplasmic C-terminus of Kv4.3 inhibits Kvβ2 association. Apparently, a region proximal to the Kv4.3 pore contributes to the inefficient auxiliary subunit interaction that produces preferential binding of Kvβ2 to Kv1 channels.

【 授权许可】

Unknown