Differential DNA binding by monomeric, homodimeric, and potentially heteromeric forms of the thyroid hormone receptor.
Binding of the thyroid hormone receptor (TR) to thyroid hormone-responsive elements (TREs) is crucial for regulation of gene expression by thyroid hormone. The TR binds to each half-site of a palindromic TRE separately, as a monomer, or simultaneously, as a homodimer. In addition, the TR monomer interacts with a 42-kDa protein that may be responsible for an increase in the apparent size and stability of the TR-TRE complex after incubation with liver nuclear extract. The multiple DNA-binding forms of the TR contact the TRE differently but compete for binding in a dynamic equilibrium which is highly dependent on the relative concentrations of TR and nuclear protein. Thus, protein-protein interactions are likely to determine the context in which the TR binds to target genes and regulates the transcriptional response to thyroid hormone.
Lazar
M A
MA
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
Berrodin
T J
TJ
Harding
H P
HP
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D004247:DNA / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D007700:Kinetics; D008110:Liver Extracts; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D051381:Rats; D011988:Receptors, Thyroid Hormone / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid
D008110:Liver Extracts; D046911:Macromolecular Substances; D011988:Receptors, Thyroid Hormone; D011994:Recombinant Proteins; D004247:DNA