Ito channels are octomeric complexes with four subunits of each Kv4.2 and K+ channel-interacting protein 2

Publication Type

Journal Article

Year of Publication

2004

Refereed Designation

Refereed

Journal

J Biol Chem

Volume

279

Pagination

5549-54

Date Published

Feb 13

ISSN

0021-9258 (Print)

Accession Number

14623880

Citation Key

67

Number

7

Keywords

*Ions, "*Potassium Channels, Voltage-Gated", Animals, Calcium-Binding Proteins/*chemistry, "Centrifugation, Density Gradient", Charybdotoxin/pharmacology, COS Cells, "Dose-Response Relationship, Drug", "Electrophoresis, Polyacrylamide Gel", Electrophysiol

Abstract

Mammalian voltage-gated K+ channels are assemblies of pore-forming alpha-subunits and modulating beta-subunits. To operate correctly, Kv4 alpha-subunits in the heart and central nervous system require recently identified beta-subunits of the neuronal calcium sensing protein family called K+ channel-interacting proteins (KChIPs). Here, Kv4.2.KChIP2 channels are purified, integrity of isolated complexes confirmed, molar ratio of the subunits determined, and subunit valence established. A complex has 4 subunits of each type, a stoichiometry expected for other channels employing neuronal calcium sensing beta-subunits.