These authors contributed equally to this work.
A Role of the Sulfonylurea Receptor 1 in Endocytic Trafficking of ATP-Sensitive Potassium Channels
Article first published online: 3 JUL 2011
© 2011 John Wiley & Sons A/S
Volume 12, Issue 9, pages 1242–1256, September 2011
How to Cite
Bruederle, C. E., Gay, J. and Shyng, S.-L. (2011), A Role of the Sulfonylurea Receptor 1 in Endocytic Trafficking of ATP-Sensitive Potassium Channels. Traffic, 12: 1242–1256. doi: 10.1111/j.1600-0854.2011.01227.x
- Issue published online: 11 AUG 2011
- Article first published online: 3 JUL 2011
- Accepted manuscript online: 7 JUN 2011 04:48AM EST
- Received 31 January 2011, revised and accepted for publication 4 June 2011, uncorrected manuscript published online 7 June 2011, published online 3 July 2011
- KATP channel;
The ATP-sensitive potassium (KATP) channel consisting of sulfonylurea receptor 1 (SUR1) and inward-rectifier potassium channel 6.2 (Kir6.2) has a well-established role in insulin secretion. Mutations in either subunit can lead to disease due to aberrant channel gating, altered channel density at the cell surface or a combination of both. Endocytic trafficking of channels at the plasma membrane is one way to influence surface channel numbers. It has been previously reported that channel endocytosis is dependent on a tyrosine-based motif in Kir6.2, while SUR1 alone is unable to internalize. In this study, we followed endocytic trafficking of surface channels in real time by live-cell imaging of channel subunits tagged with an extracellular minimal α-bungarotoxin-binding peptide labeled with a fluorescent dye. We show that SUR1 undergoes endocytosis independent of Kir6.2. Moreover, mutations in the putative endocytosis motif of Kir6.2, Y330C, Y330A and F333I are unable to prevent channel endocytosis. These findings challenge the notion that Kir6.2 bears the sole endocytic signal for KATP channels and support a role of SUR1 in this trafficking process.