Tuan D Y, Solomon W B, London I M, Lee D P
Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Cambridge 02139.
Proc Natl Acad Sci U S A. 1989 Apr;86(8):2554-8. doi: 10.1073/pnas.86.8.2554.
We have identified an erythroid-specific enhancer element far upstream of the human "beta-like globin" genes, at 10.2-11.0 kilobases 5' of the embryonic epsilon-globin gene, and thus at 53-54 kilobases 5' of the adult beta-globin gene. It is capable of enhancing the expression of a cis-linked test gene by up to 300-fold. This enhancer element is apparently developmental-stage-independent, as it is functional at the embryonic and the adult developmental stages in erythroid cells that are expressing the respective beta-like globin genes. The enhancer and globin promoter sequences work in synergy and are capable of conferring on a cis-linked gene the high transcriptional efficiency (enhancer function), erythroid specificity (enhancer and promoter functions), and developmental-stage specificity (promoter function) that are characteristic of the in vivo transcription of the beta-like globin genes in erythroid cells.
我们已经在人类“类β珠蛋白”基因上游很远的位置鉴定出一个红系特异性增强子元件，它位于胚胎ε珠蛋白基因5'端10.2 - 11.0千碱基处，因此在成人β珠蛋白基因5'端53 - 54千碱基处。它能够将顺式连接的测试基因的表达增强多达300倍。这个增强子元件显然不依赖于发育阶段，因为它在表达相应类β珠蛋白基因的红系细胞的胚胎和成人发育阶段都具有功能。增强子和珠蛋白启动子序列协同作用，能够赋予顺式连接的基因高转录效率（增强子功能）、红系特异性（增强子和启动子功能）以及发育阶段特异性（启动子功能），这些都是红系细胞中类β珠蛋白基因体内转录的特征。
