[Structure and function of TRAP].
Thyroid hormone receptor (THR) binds to specific thyroid hormone response element (TRE). Using an electrophoretic mobility shift assay (gel-shift), Murray and Towel recently found that cell nuclear extracts enhance the binding of THR to TRE. This protein has been designated T3 receptor auxiliary protein (TRAP). Retinoid X receptors (RXR alpha, beta) can function as TRAP. TRAP forms a heterodimer with THR through the ligand binding domain of both receptors. This area contains leucine zipper like heptad repeats which can form amphipathic alpha-helixes. The ligand (9-cis retinoic acid) of RXR may or may not synergistically increase T3/THR-mediated transactivation. The effects of 9-cis retinoic acid depends on the nature of the TRE. One of the functions of TRAP may be to alter the expression of T3-regulated genes.
Nakai
A
A
Department of Internal Medicine, Fujita Health University School of Medicine.
Nagasaka
A
A
D001483:Base Sequence; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology*; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014212:Tretinoin; D014284:Triiodothyronine / Q000378:metabolism
D009687:Nuclear Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014284:Triiodothyronine; D014212:Tretinoin