Scientists recently demonstrated how an ancient hormone receptor duplicated to form two specific hormonal regulation systems. Through genetic changes, one of the duplicated receptors became specific for cortisol. The other receptor surprisingly bound to aldosterone, a hormone which appeared millions of years later when four-limbed vertebrates developed the ability to produce it. Aldosterone is similarly shaped to the more ancient deoxycorticosterone (DOC), explaining the receptor's preexisting ability to bind with it.

Credit: Nicolle Rager Fuller, National Science Foundation

The molecular structure of two hormone receptors is shown. Recently, a team of University of Oregon researchers led by Joseph Thornton found that two mutations were sufficient to explain their hormone binding specificity.

Credit: Jamie Bridgham, University of Oregon