Glucose-stimulated insulin secretion (GSIS) in pancreatic beta-cells depends on coordinated glucose uptake, oxidative metabolism, and Ca(2+)-triggered insulin exocytosis. Impaired GSIS is a hallmark of type 2 diabetes. However, at present we know very little about the molecular mechanisms that induce and maintain the expression of genes required for GSIS in beta-cells. The transcription factor nuclear factor-kappaB (NF-kappaB) is activated by an increase in intracellular Ca(2+) in beta-cells. Here, we show that attenuation of NF-kappaB activation in beta-cells generates mice with impaired GSIS, and that the beta-cells show perturbed expression of genes required for glucose uptake, oxidative metabolism, and insulin exocytosis. Thus, NF-kappaB appears to be part of a positive regulatory circuit that maintains GSIS in pancreatic beta-cells.