Region-specific anti-thyroid hormone receptor (TR) antibodies detect changes in TR structure due to ligand-binding and dimerization.
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.
Yen
P M
PM
Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115.
Sugawara
A
A
Forgione
M
M
Spanjaard
R A
RA
Macchia
E
E
Cheng
S Y
SY
Chin
W W
WW
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
D018076:DNA, Complementary; D000939:Epitopes; D007518:Isoantibodies; D015345:Oligonucleotide Probes; D011988:Receptors, Thyroid Hormone; D014284:Triiodothyronine; D004247:DNA