Thyroid hormone receptors form distinct nuclear protein-dependent and independent complexes with a thyroid hormone response element

Journal Article · Thu Nov 01 00:00:00 EST 1990 · Molecular Endocrinology; (USA)

DOI:https://doi.org/10.1210/mend-4-11-1627· OSTI ID:5895522

Lazar, M A; Berrodin, T J ^[1]

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1. Univ. of Pennsylvania School of Medicine, Philadelphia (USA)

We have examined the binding of nuclear proteins and recombinant thyroid hormone receptors (TRs) to the palindromic thyroid hormone responsive element AGGTCATGACCT (TREp) using a gel electrophoretic mobility shift assay. Four specific protein-DNA complexes were detected after incubation of nuclear extracts (NE) from T3-responsive pituitary (GH3) cells with a TREp-containing DNA fragment. This was compared with the TREp binding of reticulocyte lysate-synthesized TRs. TR alpha 1 and TR beta 2 each formed a single major TR:TREp complex which comigrated with the least retarded complex formed by GH3 NE, while TR beta 1 formed multiple complexes suggesting that it can bind to TREp as an oligomer. Interestingly, coincubation of 35S-TR alpha 1, GH3 NE, and unlabeled TREp resulted in not only the 35S-TR:TREp complex, but in two additional more greatly retarded complexes containing 35S-TR alpha 1 and comigrating with those formed by GH3 extract alone. Incubation of each of the TRs with NE from COS-7 cells, which do not possess sufficient endogenous TRs to mediate T3-responses, resulted in formation of a new, more greatly shifted complex. A similar, heat labile activity which altered mobility of the TR:TRE complex was also present in NE from T3-unresponsive JEG-3 cells. At high concentration of NE, all of the TR bound to TREp was more greatly retarded than in the absence of NE. Truncation of TR alpha 1 at amino acid 210 prevented additional complex formation in the presence of NE without affecting DNA binding, suggesting that the carboxyl-terminus of the TRs is essential for interaction with nuclear proteins.

• OSTI ID: 5895522
• Journal Information: Molecular Endocrinology; (USA), Vol. 4:11; ISSN 0888-8809
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
NUCLEOPROTEINS
BIOCHEMICAL REACTION KINETICS
RECEPTORS
THYROID HORMONES
COMPLEXES
DNA
ELECTROPHORESIS
SULFUR 35
TRACER TECHNIQUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
EVEN-ODD NUCLEI
HORMONES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MEMBRANE PROTEINS
NUCLEI
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SULFUR ISOTOPES
550201* - Biochemistry- Tracer Techniques