Receptor binding models thyroid hormones

A model of thyroid hormone action is depicted in Figure 38-4, which shows the free forms of thyroid hormones, T4 and T3, dissociated from thyroid-binding proteins, entering the cell by active transport. Within the cell, T4 is converted to T3 by 5 -deiodinase, and the T3 enters the nucleus, where T3 binds to a specific T3 receptor protein, a member of the c-erb oncogene family. (This family also includes the steroid hormone receptors and receptors for vitamins A and D.) The T3 receptor exists in two forms, a and B. Differing concentrations of receptor forms in different tissues may account for variations in T3 effect on different tissues. 

Fig. 7. Model for activation by coactivators (A) and inhibition by corepressors (B) of transcription. Abbreviations CBP/p300, cAMP response element binding protein SRC-1, steroid receptor coactivator 1 TBP, TATA-binding protein TAF, TBP-associated factor pol II, RNA polymerase II N-CoR, nuclear receptor corepressor SMRT, silencing mediator of retinoic and thyroid hormone receptors.

Thyroid Hormones-Receptor Interactions Binding Models from Molecular Conformation and Binding Affinity Data... 

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