Klemenz R, Gehring W J
Mol Cell Biol. 1986 Jun;6(6):2011-9. doi: 10.1128/mcb.6.6.2011-2019.1986.
A 14-base-pair sequence element present in almost all Drosophila melanogaster heat shock genes has been implicated in the heat inducibility of transcription. The D. melanogaster gene encoding the smallest heat shock protein, hsp22, contains within its 5' flanking sequences three such repeats, two close to the transcription start site and a distally located third one 101 base pairs further upstream. Deletion analyses reveal that the 5' flanking sequences required for full expression of the hsp22 gene extend beyond the distal repeat. Deletion of the furthest upstream repeat results in a five to sixfold reduction of gene expression. The small heat shock genes are transiently expressed in the late third instar larval and early pupal stages without external stimulation. A deletion of 5' flanking sequences to position -194, which includes two nucleotides of the distal heat shock element, has no effect on the developmental expression, whereas removal of an additional 18 nucleotides, including 12 nucleotides of the distal heat shock element, severely reduces developmental expression.
几乎所有黑腹果蝇热休克基因中都存在的一个14个碱基对的序列元件与转录的热诱导性有关。编码最小热休克蛋白hsp22的黑腹果蝇基因在其5'侧翼序列中包含三个这样的重复序列，其中两个靠近转录起始位点，第三个位于更上游101个碱基对处。缺失分析表明，hsp22基因完全表达所需的5'侧翼序列延伸至远端重复序列之外。删除最上游的重复序列会导致基因表达降低五到六倍。小型热休克基因在三龄幼虫后期和蛹早期无外部刺激的情况下短暂表达。将5'侧翼序列缺失至-194位置，其中包括远端热休克元件的两个核苷酸，对发育表达没有影响，而再去除另外18个核苷酸，包括远端热休克元件的12个核苷酸，则会严重降低发育表达。
