Premium
Hyperpolarization‐activated, cyclic nucleotide‐gated HCN2 cation channel forms a protein assembly with multiple neuronal scaffold proteins in distinct modes of protein–protein interaction
Author(s) -
Kimura Kouji,
Kitano Jun,
Nakajima Yoshiaki,
Nakanishi Shigetada
Publication year - 2004
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1356-9597.2004.00752.x
Subject(s) - pdz domain , scaffold protein , hyperpolarization (physics) , biology , cyclic nucleotide binding domain , hcn channel , biophysics , microbiology and biotechnology , ion channel , protein–protein interaction , immunoprecipitation , transport protein , biochemistry , peptide sequence , signal transduction , chemistry , receptor , gene , stereochemistry , nuclear magnetic resonance spectroscopy
Hyperpolarization‐activated cation currents, termed I h , are non‐uniformly distributed along dendritic arbors with current density increasing with increasing distance from the soma. The non‐uniform distribution of I h currents contributes to normalization of location‐dependent variability in temporal integration of synaptic input, but the molecular basis for the graded HCN distribution remains to be investigated. The hyperpolarization‐activated, cyclic nucleotide‐gated cation channels (HCNs) underlie I h currents and consist of four members (HCN1‐HCN4) of the gene family in mammals. In this investigation, we report that HCN2 forms a protein assembly with tamalin, S‐SCAM and Mint2 scaffold proteins, using several different approaches including immunoprecipitation of rat brain and heterologously expressing cell extracts and glutathione S‐transferase pull‐down assays. The PDZ domain of tamalin interacts with HCN2 at both the PDZ‐binding motif and the internal carboxy‐terminal tail of HCN2, whereas binding of the PDZ domain of S‐SCAM occurs at the cyclic nucleotide‐binding domain (CNBD) and the CNBD‐downstream sequence of the carboxy‐terminal tail of HCN2. A protein assembly between HCN2 and Mint2 is formed by the interaction of the munc18‐interacting domain of Mint2 with the CNBD‐downstream sequence of HCN2. The results demonstrate that HCN2 forms a protein complex with multiple neuronal scaffold proteins in distinct modes of protein–protein interaction.