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Differential association of the auxiliary subunit Kvβ2 with Kv1.4 and Kv4.3 K + channels
Author(s) -
Wang Lin,
Takimoto Koichi,
Levitan Edwin S
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00705-1
Subject(s) - protein subunit , biophysics , cytoplasm , chemistry , hek 293 cells , potassium channel , microbiology and biotechnology , biology , biochemistry , receptor , gene
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.