Ecdysone binding proteins in nuclei and chromatin from Drosophila salivary glands

• Published in: General and comparative endocrinology Vol. 19; no. 3; pp. 543 - 551
• Main Author: Emmerich, Hans
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.1972
• Subjects: Animals; Cell Fractionation; Cell Nucleus - metabolism; Centrifugation, Density Gradient; Chromatin - metabolism; Cytoplasm - metabolism; Deoxyribonucleases; Drosophila - anatomy & histology; Ecdysone - metabolism; Electrophoresis; Filtration; Potassium Chloride; Pronase - pharmacology; Protein Binding; Ribonucleases - pharmacology; Salivary Glands - cytology; Salivary Glands - metabolism; Temperature; Tritium
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/0016-6480(72)90254-7

After treatment of salivary glands isolated from Drosophila hydei with tritiumlabeled eedysone, complexes of the radioactive hormone and protein(s) can be isolated. Fractions containing these complexes have been obtained from cytoplasmic and nuclear extracts by means of filtration, density gradient centrifugation, and agar electrophoresis. By extractions at low ionic strength, an 8 S hormone acceptor is obtained which is derived from the cytoplasm. After extraction with 0.4 M KCL, a complex sedimenting at approximately 4 S is demonstrable. These complexes are susceptible to temperature and pronase, they are not degraded by DNase, or by RNase. Agar electrophoresis reveals that the 0.4 M KCl extractable acceptors are heterogeneous. Small amounts of radioactive ecdysone are associated with chromatin prepared from glands that were incubated with the hormone. The major portion of chromatin-bound hormone is found in the nonhistone protein fraction. The hormone is not covalently bound to the proteins. Purified chromatin from untreated glands binds ecdysone upon in vitro incubation, but to a lesser extent than under in vivo conditions.