Referenced in: none

Automatically associated channels: KChIP1 , Kv1.2 , Kv1.4 , Kv3.1 , Kv4.2 , Kv4.3

Title: Two N-terminal domains of Kv4 K(+) channels regulate binding to and modulation by KChIP1.

Authors: Robert H Scannevin, Kewei Wang, Flora Jow, Jennifer Megules, David C Kopsco, Wade Edris, Karen C Carroll, Qiang Lü, Weixin Xu, Zhangbao Xu, Alan H Katz, Stephane Olland, Laura Lin, Meggin Taylor, Mark Stahl, Karl Malakian, Will Somers, Lydia Mosyak, Mark R Bowlby, Pranab Chanda, Kenneth J Rhodes

Journal, date & volume: Neuron, 2004 Feb 19 , 41, 587-98

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/14980207

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.