Control of thyroglobulin gene transcription by TSH and cAMP.

The availability of the sequence of Tg promoter from three different species enabled a fruitful comparison to be made from which a general picture of the organization of the Tg gene promoter region emerged. Chromatin structure studies identified tissue-specific modifications at the level of DNA protein interactions. A DNA element has been shown to be involved in transcription control by cAMP. This sequence includes a highly conserved region of the Tg gene promoter, overlaps a domain of the promoter which becomes hypersensitive to DNase I when the gene is expressed and displays specific protein-DNA interaction. These observations are consistent with the possibility that this sequence is a target element for trans-acting factor(s) which control(s) the transcriptional activity of the gene.