Demonstration of an ecdysteroid receptor in a cultured cell line of Drosophila melanogaster.

Abstract

30 min results in a marked binding of the ligand by a KCI-soluble nuclear extract. With both the cytosol and nuclear preparations the binding has specificity and a low dissociation constant (3 X 10-9 M). In addition the labeling of the nuclear preparation exhibits a saturation at approximately 7 X 10-10 M which probably reflects the molar concentration of cytoplasmic receptors.

Identification and characterization of the ecdysterone receptor in Drosophila melanogaster by photoaffinity labeling

“…Bonded hormone was measured after irradiation of the charcoal-treated incubation mixture followed by trichloroacetic acid precipitation. The data of Table 1 show that we found about 1300 receptor molecules per Kc cell, which is in good agreement with previously published figures (4,5). Twenty-five percent ofthe bound hormone became covalently bonded upon photoactivation.…”

“…Because photoactivation of ecdysterone induced specific covalent binding of hormone to defined chromosomal sites, it was intriguing to investigate and to identify the nature of the molecule(s) that reacted with ecdysterone upon irradiation. We report in this paper that ecdysterone becomes covalently linked to a single protein, which has the properties of the ecdysteroid-receptor molecule (4,5).…”

Identification of ecdysone response elements by analysis of the Drosophila Eip28/29 gene.

“…Thus, active ecdysones are known to bind with appropriate affinities to a nuclear protein (or proteins) present at low abundance in responsive cells and thought to be receptor(s) (Maroy et al 1978;Yund et al 1978;Sage et al 1982;Cherbas et al 1988), and a number of genes with the response characteristics of immediate hormone targets ("early effects") are known (for review, see Cherbas et al 1986a;Ashburner 1990;Segraves and Richards 1990). Using one of these genes (hsp27], Riddihough and Pelham (1987) described an upstream sequence sufficient to confer hormonal inducibility in transient assays.…”

Catalase is Induced by Ecdysterone and Ethanol in Drosophila Cells

“…It was demonstrated that, 'sensitive', receptor-positive [7,8] cells present a wide range of specific responses to ecdysterone (an hormonal steroid of critical importance in the development and the differentiation of insects [9]) : (a) morphological modifications [lo], (b) the arrest of division [I 1 -131, (c) the induction of about 10 polypeptides [14-191 and (d) the induction of acetylcholinesterase [20,21] and of 8-galactosidase [22]. It was also demonstrated that these enzymatic inductions are modulated during an hormonal maturation period which renders the cell more 'competent' to respond [23].…”