Mutational analysis of the interaction between ecdysteroid receptor and its response element.
The interaction between the partially purified ecdysteroid receptor (EcR) and the mutated ecdysteroid-response element (EcRE) from the hsp27 gene promoter was studied using the gel retardation competition assay. The results suggest that the EcR-hsp27 EcRE contact sites are made predominantly by base pairs which are at positions -7, -6, -5, -2, -1 and +2, +5, +6 of the hsp27 EcRE palindrome. An increase or decrease in the spacing between the half-palindromes reduces the affinity of the hsp27 EcRE to the receptor, while a mutation of the central A/T base pair to C/G has practically no effect on EcR binding. Unlike the glucocorticoid-response element and the estrogen-response element, the base pairs placed at positions -3, -4 and +1, +3, +4 of the hsp27 EcRE palindrome can be mutated without effect on the EcR binding.
Oźyhar
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A
Technical University of Wroclaw, Institute of Organic and Physical Chemistry, Poland.
Pongs
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O
D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D004247:DNA; D004252:DNA Mutational Analysis; D004331:Drosophila melanogaster / Q000378:metabolism; D004441:Ecdysterone / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid
D006360:Heat-Shock Proteins; D011987:Receptors, Steroid; C034808:ecdysteroid receptor; D004441:Ecdysterone; D004247:DNA