All Nuclear Receptors

Question

All nuclear receptors ...
A) are cytosolic proteins that enter the nucleus upon ligand binding.
B) have ligand-binding and DNA-binding domains, and can directly bind to DNA.
C) are transcriptional activators when bound to their ligand.
D) bind to steroid hormones.
E) are transcriptional repressors in the absence of their ligand.

Accepted Answer

Nuclear receptors have at least a ligand-binding domain and a DNA-binding domain. Some of them only enter the nucleus after ligand binding, whereas others are present inside the nucleus even in the absence of their ligand. Their ligands are typically small hydrophobic molecules such as steroid hormones and thyroid hormones. Some nuclear receptors are transcriptional activators, whereas others are transcriptional repressors.