In vitro transcription of the human insulin gene

Insulin gene transcription is a highly tissue specific process which only takes place in the pancreatic beta-cell, and may be explained by the interaction of a unique composition of transacting factors and insulin gene 5' enhancer/promoter elements. In order to study differences in transcription factors from either insulin or non insulin producing cell lines we have developed an in vitro transcription assay of the human insulin gene. Efficient transcription was obtained using nuclear extracts from insulin as well as non insulin producing cell lines, and we were so far not able to mimic in vivo conditions present in beta-cells. The method is now routinely being used to test the activity of nuclear extracts before they are used in other analyses such as gel retardation assays and footprinting experiments.