Diabetic pancreatic beta cells ARNT all they should be.

A complex network of interacting transcription factors plays a critical role in normal pancreatic beta cell function, with mutations in certain transcription factor genes known to cause diabetes. In a recent issue of Cell, Gunton et al.(2005) demonstrate a role for the transcription factor ARNT/HIF1beta (hydrocarbon nuclear receptor translocator/hypoxia-inducible factor 1 beta) in normal beta cell function. ARNT expression is reduced in diabetic human islets and beta cell-specific ARNT knockout mice show the impaired glucose tolerance and abnormal insulin secretion that are characteristic of type 2 diabetes.