English: Created myself using CambridgeSoft BioDraw. Mechanism nuclear receptor action. This figure depicts the mechanism of a class II nuclear receptor (NR) which, regardless of ligand binding status is located in the nucleus bound to DNA. For the purpose of illustration, the nuclear receptor shown here is the thyroid hormone receptor (TR) heterodimerized to the RXR. In the absence of ligand, the TR is bound to corepressor protein. Ligand binding to TR causes a dissociation of corepressor and recruitment of coactivator protein which in turn recruit additional proteins such as RNA polymerase that are responsible for transcription of downstream DNA into RNA and eventually protein which results in a change in cell function.