Agonist-free transformation of the glucocorticoid receptor in human B-lymphoma cells.

Nuclear translocation of activated glucocorticoid receptors (GRs) is a necessary step in the signal transduction by these GC hormones. Although in vitro activation of GRs can occur in the absence of a functional ligand, it is generally assumed that binding of a cognate hormone is required for activation of the ...
intracellular GR. By indirect immunocytochemistry and Western-blot analysis, it was found that, in spontaneously aggregated human lymphoma DoHH2 cells, hormone-free GRs are located in the nucleus. Disruption of the aggregates redistributed GRs to a predominantly cytosolic location. Upon spontaneous re-aggregation the GR again became localized to the nucleus. Intracellular cross-linking of the heteromeric receptor complex was applied to investigate the protein composition of cytoplasmic and nuclear receptors. Untransformed, cytosolic GRs could be demonstrated by [3H]dexamethasone binding capacity and hsp90 co-immunoprecipitation, whereas absence of these characteristics suggested an activated conformation of the nuclear GRs. These observations suggest that cell-cell interactions are capable of transforming GRs in the absence of a ligand.
Mesh Terms:
Adenosine Diphosphate, Adenosine Triphosphate, Binding Sites, Cell Cycle, Cell Nucleus, Cross-Linking Reagents, Cytosol, Dexamethasone, Glucocorticoids, HSP90 Heat-Shock Proteins, Humans, Ligands, Lymphoma, B-Cell, Receptor Aggregation, Receptors, Glucocorticoid, Signal Transduction, Succinimides, Tumor Cells, Cultured
J. Steroid Biochem. Mol. Biol.
Date: Feb. 01, 1996
Download Curated Data For This Publication
3512
Switch View:
  • Interactions 1