Raloxifene and ICI182,780 Increase Estrogen Receptor-α Association with a Nuclear Compartment via Overlapping Sets of Hydrophobic Amino Acids in Activation Function 2 Helix 12
| Autor: | M. Jeyakumar, Anick Auger, Dino Moras, Sylvie Mader, Elise Hébert, Mathieu Lupien, Khalid Hilmi, Geneviève Anne Pinard, David Cotnoir-White, Jean Marie Wurtz, John A. Katzenellenbogen, Guila Dayan, Caroline Loch |
|---|---|
| Přispěvatelé: | Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de génétique et biologie moléculaire et cellulaire (IGBMC), Université Louis Pasteur - Strasbourg I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC) |
| Rok vydání: | 2007 |
| Předmět: |
MESH: Amino Acids
Transcription Genetic Amino Acid Motifs MESH: Protein Structure Secondary Estrogen receptor MESH: Amino Acid Sequence Protein Structure Secondary MESH: Amino Acid Motifs Transactivation 0302 clinical medicine Endocrinology Protein structure Tumor Cells Cultured Amino Acids Receptor Fulvestrant MESH: Estrogen Receptor alpha 0303 health sciences Estradiol Estrogen Antagonists General Medicine Transfection MESH: Amino Acid Substitution Cell biology Biochemistry 030220 oncology & carcinogenesis Trefoil Factor-1 MESH: Estradiol hormones hormone substitutes and hormone antagonists MESH: Cell Nucleus MESH: Mutation Molecular Sequence Data MESH: Estrogen Antagonists Biology 03 medical and health sciences Leucine Humans MESH: Tumor Suppressor Proteins Amino Acid Sequence MESH: Tumor Cells Cultured Molecular Biology Estrogen receptor beta 030304 developmental biology Cell Nucleus MESH: Raloxifene MESH: Molecular Sequence Data MESH: Humans Tumor Suppressor Proteins MESH: Transcription Genetic Estrogen Receptor alpha [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry Molecular Biology/Molecular biology Antiestrogen MESH: Solubility MESH: Leucine Amino Acid Substitution Solubility Raloxifene Hydrochloride Mutation Estrogen receptor alpha |
| Zdroj: | Molecular Endocrinology-Baltimore Molecular Endocrinology-Baltimore-, Endocrine Society, 2007, 21 (4), pp.797-816. ⟨10.1210/me.2006-0074⟩ |
| ISSN: | 1944-9917 0888-8809 |
| Popis: | The basis for the differential repressive effects of antiestrogens on transactivation by estrogen receptor-α (ERα) remains incompletely understood. Here, we show that the full antiestrogen ICI182,780 and, to a lesser extent, the selective ER modulator raloxifene (Ral), induce accumulation of exogenous ERα in a poorly soluble fraction in transiently transfected HepG2 or stably transfected MDA-MB231 cells and of endogenous receptor in MCF7 cells. ERα remained nuclear in HepG2 cells treated with either compound. Replacement of selected hydrophobic residues of ERα ligand-binding domain helix 12 (H12) enhanced receptor solubility in the presence of ICI182,780 or Ral. These mutations also increased transcriptional activity with Ral or ICI182,780 on reporter genes or on the endogenous estrogen target gene TFF1 in a manner requiring the integrity of the N-terminal AF-1 domain. The antiestrogen-specific effects of single mutations suggest that they affect receptor function by mechanisms other than a simple decrease in hydrophobicity of H12, possibly due to relief from local steric hindrance between these residues and the antiestrogen side chains. Fluorescence anisotropy experiments indicated an enhanced regional stabilization of mutant ligand-binding domains in the presence of antiestrogens. H12 mutations also prevent the increase in bioluminescence resonance energy transfer between ERα monomers induced by Ral or ICI182,780 and increase intranuclear receptor mobility in correlation with transcriptional activity in the presence of these antiestrogens. Our data indicate that ICI182,780 and Ral locally alter the ERα ligand binding structure via specific hydrophobic residues of H12 and decrease its transcriptional activity through tighter association with an insoluble nuclear structure. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|