Mineralocorticoid-specific elements

A. Mechanism of Action Corticosteroids enter the cell and bind to cytosolic receptors that transport the steroid into the nucleus. The steroid-receptor complex alters gene expression by binding to glucocorticoid response elements (GREs) or mineralocorticoid-specific elements (Figure 39-2). Tissue-specific responses to steroids are made possible by the presence in each tissue of different protein regulators that control the interaction between the hormone-receptor complex and particular response elements. 

Fig. 5. Specificity of steroid response element. A. In this example (mouse mammary tumour virus), the element will bind receptors for glucocorticoids (G), androgen (A), progestin (P) and mineralocorticoid (M) so that each of these classes of steroid stimulate transcription. This type of specificity can vary from cell to cell possibly due to other protein factors (not shown). B. Although oestrogen (E) receptor will not act as an agonist for mouse mammary tumour virus transcription, it may antagonise the agonist activity of glucocorticoids (G).

---