Hudson L G, Thompson K L, Xu J, Gill G N
Department of Medicine, University of California-San Diego, La Jolla 92093.
Proc Natl Acad Sci U S A. 1990 Oct;87(19):7536-40. doi: 10.1073/pnas.87.19.7536.
We have identified a 36-base-pair proximal element (-112 to -77 relative to the AUG translation initiation codon) in the epidermal growth factor receptor 5' region that functions as a promoter; mediates inductive responses to epidermal growth factor, phorbol 12-myristate 13-acetate, and cyclic AMP; and acts in an orientation-independent manner. This region functions as an enhancer when transferred to a heterologous promoter containing a TATA box. Mutations within the 36-base-pair region alter function as assayed by reporter gene expression in recipient cells. A protein has been identified that demonstrates appropriate binding specificity to mutant DNA sequences that correlates with promoter activity observed in vivo. On the basis of DNA binding characteristics and size, the identified protein appears distinct from several previously identified transcription factors known to bind to G+C-rich regions.
我们在表皮生长因子受体5'区域鉴定出一个36个碱基对的近端元件(相对于AUG翻译起始密码子为-112至-77),该元件具有启动子功能;介导对表皮生长因子、佛波酯12-肉豆蔻酸酯13-乙酸酯和环磷酸腺苷的诱导反应;并且以方向独立的方式起作用。当转移到含有TATA框的异源启动子时,该区域具有增强子功能。通过报告基因在受体细胞中的表达检测,36个碱基对区域内的突变会改变功能。已鉴定出一种蛋白质,它对突变DNA序列表现出适当的结合特异性,这与体内观察到的启动子活性相关。基于DNA结合特性和大小,所鉴定的蛋白质似乎不同于先前鉴定的几种已知与富含G+C区域结合的转录因子。