Year: 1997
Type: article
Abstract: ATP-sensitive potassium (KATP) channels link cellular metabolism to electrical activity in nerve, muscle, and endocrine tissues. They are formed as a functional complex of two unrelated subunits-a member of the Kir inward rectifier potassium channel family, and a sulfonylurea receptor (SUR), a member of the ATP-binding cassette transporter family, which includes cystic fibrosis transmembrane conductance regulators and multidrug resistance protein, regulators of chloride channel activity. This recent discovery has brought together proteins from two very distinct superfamilies in a novel functional complex. The pancreatic KATP channel is probably formed specifically of Kir6.2 and SUR1 isoforms. The relationship between SUR1 and Kir6.2 must be determined to understand how SUR1 and Kir6.2 interact to form this unique channel. We have used mutant Kir6.2 subunits and dimeric (SUR1-Kir6.2) constructs to examine the functional stoichiometry of the KATP channel. The data indicate that the KATP channel pore is lined by four Kir6.2 subunits, and that each Kir6.2 subunit requires one SUR1 subunit to generate a functional channel in an octameric or tetradimeric structure.
Authors: S.-L. Shyng, C.G. Nichols
Institution: Washington University in St. Louis
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2061787346