Karlsson O, Edlund T, Moss J B, Rutter W J, Walker M D
Department of Microbiology, University of Umea, Sweden.
Proc Natl Acad Sci U S A. 1987 Dec;84(24):8819-23. doi: 10.1073/pnas.84.24.8819.
Cell-specific expression of the insulin gene is controlled by cis-acting DNA sequences located within approximately equal to 350 base pairs of the 5' flanking DNA immediately upstream from the transcription start site. Using synthetic oligonucleotides, we have constructed a systematic series of block replacement mutants spanning this region. No single sequence appears to be absolutely required for expression. However, three of the mutants exhibit 5-10 times less activity and several others show 2-3 times less. Simultaneous mutation of two of the most mutationally sensitive regions leads to virtual abolition of activity. These two elements are structurally related and presumably represent key components of the machinery determining the cell-specific expression of the insulin gene.
胰岛素基因的细胞特异性表达受位于转录起始位点上游约350个碱基对的5'侧翼DNA内的顺式作用DNA序列控制。我们使用合成寡核苷酸构建了一系列跨越该区域的系统性片段置换突变体。似乎没有单一序列对于表达是绝对必需的。然而，其中三个突变体的活性降低了5至10倍，其他几个则降低了2至3倍。两个对突变最敏感的区域同时发生突变会导致活性几乎完全丧失。这两个元件在结构上相关，推测代表了决定胰岛素基因细胞特异性表达机制的关键组分。
