Probing nucleotide interactions with Kir6.2 using fluorescence spectroscopy. (360G-Wellcome-203731_Z_16_A)

The ATP-sensitive potassium (KATP) channel is a plasma membrane protein present in beta cells of the pacreas which plays a key role in insulin secretion. KATP acts as a metabolic sensor, alerting the beta cells when blood glucose raises too high and stimulating them to release insulin. In diabetes, normal KATP function is disrupted and beta cells no longer secrete insulin properly in response to blood glucose levels. The molecular structure of the channel is closely linked to its function; there have been several genetic studies linking various mutations (which often only affect one molecule in the channel!) to neonatal diabetes or increased propensity to type II diabetes. Our research aims to identify precisely how these small mutations can have such drastic changes in the activity of the channel by using a combination of fluorescent labels and channel current measurements to watch the KATP channel move in real time. We can then try to construct a model of how the channel converts different stimuli into movements, and how this is affected in mutations linked to diabetes.