We measured glucagon secretion from mouse islets infected with green fluorescent protein (Ad-GFP; open circles/bars) or SUMO1 (Ad-SUMO1; black circles/bars) during perifusion. A, glucagon secretion in response to 1 mm glucose followed by 20 mm KCl. Areas under the curve (AUCs) for the various conditions are shown on the right. B, glucagon secretion in response to 1 mm glucose followed by 10 nm exendin 4. AUCs for the various conditions are shown on the right. C, glucagon secretion in response to 1 mm glucose followed by 10 μm adrenaline. AUCs for the various conditions are shown on the right. *P < 0.05, **P < 0.01, ***P < 0.001 for comparisons with the Ad-GFP control.