Paul J, Allan M, Gilmour S, Spandidos D, Montague P, Grindlay J, Vass K, Zhu J D, Gow J
Prog Clin Biol Res. 1985;191:29-48.
Besides the major cap site, transcription of the human epsilon-globin gene initiates at several upstream sites, the furthest 4.5 kb away. The upstream initiation sites occur in regions of hypersensitivity to DNaseI. There is also a very prominent DNaseI hypersensitive site 6.5 kb upstream which corresponds to an unusual nucleotide sequence. Upstream promoters, particularly one 200 bp upstream can be regulated independently of the major cap site. This site behaves as if it were a unidirectional enhancer. A fragment upstream of the mouse beta-globin promoter acts as a negative regulator in cis; it contains a long stretch of alternating purine and pyrimidine bases. The significance of upstream regulatory sequences adjacent to globin genes is discussed.
除了主要的帽位点外，人类ε-珠蛋白基因的转录还起始于几个上游位点，最远的距离为4.5 kb。上游起始位点出现在对DNaseI敏感的区域。在距离上游6.5 kb处还有一个非常显著的DNaseI超敏位点，它对应着一段异常的核苷酸序列。上游启动子，尤其是上游200 bp处的启动子，可以独立于主要帽位点进行调控。这个位点的行为就好像它是一个单向增强子。小鼠β-珠蛋白启动子上游的一个片段在顺式作用中起负调控作用；它包含一段长的嘌呤和嘧啶碱基交替序列。文中讨论了与珠蛋白基因相邻的上游调控序列的意义。
