Originally Published In
Glaser RL, Thomas GH, Siegfried E, Elgin SC, Lis JT. Optimal heat-induced expression of the Drosophila hsp26 gene requires a promoter sequence containing (CT)n.(GA)n repeats. J Mol Biol. 1990;211(4):751–761. doi:10.1016/0022-2836(90)90075-W
We report here the analysis of the sequence requirements for the heat-induced expression of the Drosophila melanogaster hsp26 gene using germline transformation. Heat-induced expression is augmented fivefold by a homopurine/homopyrimidine region from -85 to -134 that is devoid of heat-shock elements but contains numerous (dC-dT).(dG-dA) repeats. Sequences within this interval have been shown to assume a nuclease S1-hypersensitive structure in vitro. In this paper, we extend those in vitro observations, demonstrating that the S1-hypersensitive structure is triple-helical H-DNA formed by a symmetric (dC-dT).(dG-dA) sequence. Thus, the sequences that form H-DNA in vitro are also required in vivo for optimal hsp26 transcription. However, mutational analysis and diethylpyrocarbonate modification experiments in isolated nuclei suggest that the (dC-dT).(dG-dA) sequence does not form H-DNA in vivo and argue against a role for H-DNA in the heat-induced expression of hsp26.
Glaser, R; Thomas, Graham H.; Siegfried, Ester; Elgin, Sarah C.R.; and Lis, J, "Optimal heat-induced expression of the Drosophila hsp26 gene requires a promoter sequence containing (CT)n.(GA)n repeats" (1990). Biology Faculty Publications & Presentations. 224.