Lonigro R, De Felice M, Biffali E, Macchia P E, Damante G, Asteria C, Di Lauro R
Department of Science and Biomedical Technology, University of Udine, Italy.
Cell Growth Differ. 1996 Feb;7(2):251-61.
The complete structure of the gene for thyroid transcription factor 1 (TTF-1), both in rats and humans, has been determined. The rat TTF-1 gene shows three transcriptional start sites and contains two introns, one of which is alternatively spliced. Nuclear run-on and transient transfection experiments indicate that TTF-1 gene expression can be controlled at different levels. Using thyroid and nonthyroid cell lines, it can be shown that transcriptional mechanisms are involved in controlling thyroid-specific expression of the TTF-1 gene. In contrast, in thyroid cells expressing an activated Ki-ras oncogene, the steady-state level of TTF-1 mRNA is greatly reduced, while transcription of the TTF-1 gene is only moderately affected, suggesting that the accumulation of TTF-1 mRNA can be regulated by a posttranscriptional, Ras-sensitive mechanism.
甲状腺转录因子1（TTF-1）在大鼠和人类中的基因完整结构已被确定。大鼠TTF-1基因有三个转录起始位点，包含两个内含子，其中一个存在可变剪接。细胞核连续转录和瞬时转染实验表明，TTF-1基因表达可在不同水平受到调控。利用甲状腺和非甲状腺细胞系可以证明，转录机制参与了TTF-1基因甲状腺特异性表达的调控。相反，在表达激活型Ki-ras癌基因的甲状腺细胞中，TTF-1 mRNA的稳态水平大幅降低，而TTF-1基因的转录仅受到适度影响，这表明TTF-1 mRNA的积累可通过一种转录后、Ras敏感机制进行调控。
