Dynamic duo: Kir6 and SUR in K_ATP channel structure and function

ABSTRACT

K_ATP channels are ligand-gated potassium channels that couple cellular energetics with membrane potential to regulate cell activity. Each channel is an eight subunit complex comprising four central pore-forming Kir6 inward rectifier potassium channel subunits surrounded by four regulatory subunits known as the sulfonylurea receptor, SUR, which confer homeostatic metabolic control of K_ATP gating. SUR is an ATP binding cassette (ABC) protein family homolog that lacks membrane transport activity but is essential for K_ATP expression and function. For more than four decades, understanding the structure-function relationship of Kir6 and SUR has remained a central objective of clinical significance. Here, we review progress in correlating the wealth of functional data in the literature with recent K_ATP cryoEM structures.

KEYWORDS:

• ATP-sensitive potassium channel
• ABC transporter
• inward rectifier potassium channel
• sulfonylurea receptor
• Kir6.2
• cryo-EM

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study.

Additional information

Funding

This work was supported by National Institutes of Health grant DK066485, GM145784 and GM145784S1 (to Show-Ling Shyng).