Two N-terminal domains of Kv4 K(+) channels regulate binding to and modulation by KChIP1.Scannevin, R.H., Wang, K.-W., Jow, F., Megules, J., Kopsco, D.C., Edris, W., Carroll, K.C., Xu, W.-X., Xu, Z.-B., Katz, A.H., Olland, S., Lin, L., Taylor, M., Stahl, M., Malakian, K., Somers, W., Mosyak, L., Bowlby, M.R., Chanda, P., Rhodes, K.J.
(2004) Neuron 41: 587-598
- PubMed: 14980207
- DOI: https://doi.org/10.1016/s0896-6273(04)00049-2
- Primary Citation of Related Structures:
- PubMed Abstract:
The family of calcium binding proteins called KChIPs associates with Kv4 family K(+) channels and modulates their biophysical properties. Here, using mutagenesis and X-ray crystallography, we explore the interaction between Kv4 subunits and KChIP1. Two regions in the Kv4.2 N terminus, residues 7-11 and 71-90, are necessary for KChIP1 modulation and interaction with Kv4.2. When inserted into the Kv1.2 N terminus, residues 71-90 of Kv4.2 are also sufficient to confer association with KChIP1. To provide a structural framework for these data, we solved the crystal structures of Kv4.3N and KChIP1 individually. Taken together with the mutagenesis data, the individual structures suggest that that the Kv4 N terminus is required for stable association with KChIP1, perhaps through a hydrophobic surface interaction, and that residues 71-90 in Kv4 subunits form a contact loop that mediates the specific association of KChIPs with Kv4 subunits.
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