Figure 2. Steroid hormone receptor signalling.

Steroid Hormone Receptors (SHR) act as hormone dependent nuclear transcription factors. Upon entering the cell by passive diffusion, the hormone (H) binds the receptor, which is subsequently released from heat shock proteins, and translocates to the nucleus. There, the receptor dimerizes, binds specific sequences in the DNA, called Hormone Responsive Elements or HREs, and recruits a number of coregulators that facilitate gene transcription. This latter step can be modulated by receptor antagonists like tamoxifen (T), and cellular signalling pathways. Examples of processes studied using biophysical techniques and discussed in this review include: hormone binding (1), chaperone interaction (2), nuclear translocation (3), receptor dimerization (4), DNA binding (5), putative membrane-bound receptors (6), coregulator recruitment (7), transcription (8), proteasomal degradation (9), modulation by cellular signalling pathways (10), and antagonist resistance (11).