The structure of the human thyrotropin beta-subunit gene.

We have determined and characterized the entire structure of the human thyrotropin beta-subunit (TSH beta) gene. It is 4.5 kb in size and separated into three exons. Primer extension analysis showed one transcription start point, and S1 mapping analysis showed two blocks of polyadenylation sites in normal pituitaries. The same transcripts were observed in TSH-producing adenomas. The 5'-flanking region contains two 'TATA' boxes, two 'CAAT' boxes, and two sequences similar to the cyclic AMP-responsive elements.