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Association of β-catenin with the α-subunit of neuronal large-conductance Ca 2+ -activated K+ channels

2003; National Academy of Sciences; Volume: 101; Issue: 2 Linguagem: Inglês

10.1073/pnas.0307681100

1091-6490

Florian Lesage, Hiroshi Hibino, A. J. Hudspeth,

Ion Channels and Receptors

The association of Ca 2+ -activated K + channels with voltage-gated Ca 2+ channels at the presynaptic active zones of hair cells, photoreceptors, and neurons contributes to rapid repolarization of the membrane after excitation. Ca 2+ channels have been shown to bind to a large set of synaptic proteins, but the proteins interacting with Ca 2+ -activated K + channels remain unknown. Here, we report that the large-conductance Ca 2+ -activated K + channel of the chicken's cochlear hair cell interacts with β-catenin. Yeast two-hybrid assays identified the S10 region of the K + channel's α-subunit and the ninth armadillo repeat and carboxyl terminus of β-catenin as necessary for the interaction. An antiserum directed against the α-subunit specifically coprecipitated β-catenin from brain synaptic proteins. β-Catenin is known to associate with the synaptic protein Lin7/Velis/MALS, whose interaction partner Lin2/CASK also binds voltage-gated Ca 2+ channels. β-Catenin may therefore provide a physical link between the two types of channels at the presynaptic active zone.