Abstract
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.
Original language | English (US) |
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Pages (from-to) | 751-761 |
Number of pages | 11 |
Journal | Journal of Molecular Biology |
Volume | 211 |
Issue number | 4 |
DOIs | |
State | Published - Feb 20 1990 |
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology