Biochem/physiol Actions

Nuclear receptors form the largest known family of transcription factors and have a crucial role in nearly all aspects of vertebrate development and adult physiology by transducing the effects of hormones into transcriptional responses. The family is defined by two domains: (a) the central, highly conserved, DNA-binding domain (DBD) of approx. 66 amino acids, and (b) the C-terminal, structurally conserved, ligand-binding domain (LBD) of approximately 250 amino acids. The amino-terminal regions are least conserved among nuclear receptor sequences. This domain is highly divergent between the TR and TR isoforms, which suggests differential roles in transcriptional regulation. In addition, alternative splicing of the TR gene generates two isoforms, TR 1 and TR 2 with completely different amino-terminal domains. Unliganded TR inhibits the formation of a functional pre-initiation complex through direct interaction with TBP and transcription factor IIB. Additionally, in the absence of ligand, TR has been shown to repress transcription through recruitment of a corepressor complex, which also includes Sin3A and histone deacetylase. Ligand binding releases the corepressor complex and recruits a coactivator complex that includes multiple histone acetyltransferases, including a steroid receptor family coactivator, p300/CREB-binding protein-associated factor (PCAF), and CREB binding protein (CBP).

Physical form

Clear and colorless frozen liquid solution

Preparation Note

Use a manual defrost freezer and avoid repeated freeze-thaw cycles. While working, please keep sample on ice.