Amin J, Mestril R, Schiller P, Dreano M, Voellmy R
Mol Cell Biol. 1987 Mar;7(3):1055-62. doi: 10.1128/mcb.7.3.1055-1062.1987.
Expression from the Drosophila melanogaster hsp70 promoter was controlled by a regulatory unit that was composed of two sequence elements that resembled the heat shock consensus sequence. The unit functioned in both orientations and at different distances from downstream promoter sequences. Each element of the unit alone was essentially inactive. Association of two elements resulted in a dramatic increase of transcription from the hsp70 promoter. This synergistic effect was independent of the relative orientation of the elements and, to a large extent, of the distance between them. Duplication of a region containing only one element also yielded a highly active, heat-regulated promoter. Genes with three to five elements were three to four times more active than those with a single regulatory unit.
果蝇热休克蛋白70（hsp70）启动子的表达受一个调控单元的控制，该调控单元由两个类似于热休克共有序列的序列元件组成。该单元在两个方向上均起作用，且与下游启动子序列的距离不同时也能起作用。该单元的每个元件单独作用时基本无活性。两个元件结合会导致hsp70启动子的转录显著增加。这种协同效应与元件的相对方向无关，并且在很大程度上与它们之间的距离无关。仅包含一个元件的区域的重复也产生了一个高度活跃的、受热调控的启动子。含有三到五个元件的基因的活性比含有单个调控单元的基因高两到三倍。
