title: Region-specific anti-thyroid hormone receptor (TR) antibodies detect changes in TR structure due to ligand-binding and dimerization.
abstract: There are multiple factors that potentially can induce structural changes in DNA-bound thyroid hormone receptors (TRs) including protein-protein interactions, ligand-binding to TRs, and the thyroid hormone response element (TRE) sequence. We used a battery of anti-TR antibodies that recognize the amino-terminal, hinge, or carboxy-terminal regions of TRs to study changes in the epitope regions of in vitro translated TRs in electrophoretic mobility shift assays. We found that the carboxy-terminal and hinge region antibodies recognized TR homodimers but not TR/T3-receptor auxiliary protein or TR/retinoid X receptor heterodimers. The amino-terminal antibodies detected conformational changes due to ligand binding. In contrast, each antibody recognized TR complexes bound to TREs containing half-sites arranged in three different orientations. These results suggest that dimerization with nuclear proteins and ligand-binding, rather than the orientation of TRE half-sites, cause changes in several TR subregions.
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115.
authors.forename: P M
authors.initials: PM
authors.lastname: Yen
authors.forename: A
authors.initials: A
authors.lastname: Sugawara
authors.forename: M
authors.initials: M
authors.lastname: Forgione
authors.forename: R A
authors.initials: RA
authors.lastname: Spanjaard
authors.forename: E
authors.initials: E
authors.lastname: Macchia
authors.forename: S Y
authors.initials: SY
authors.lastname: Cheng
authors.forename: W W
authors.initials: WW
authors.lastname: Chin
mesh_terms: D000918:Antibody Specificity; D001665:Binding Sites; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007518:Isoantibodies / Q000276:immunology; D015345:Oligonucleotide Probes; D011485:Protein Binding; D011487:Protein Conformation; D011988:Receptors, Thyroid Hormone / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D000939:Epitopes; D007518:Isoantibodies; D015345:Oligonucleotide Probes; D011988:Receptors, Thyroid Hormone; D014284:Triiodothyronine; D004247:DNA