Preserved in Portico This version is not peer-reviewed
Transcriptional Activation of Elephant Shark Mineralocorticoid Receptor by Corticosteroids, Progesterone and Spironolactone
: Received: 27 February 2019 / Approved: 1 March 2019 / Online: 1 March 2019 (06:37:37 CET)
We report the analysis of activation by corticosteroids and progesterone of full-length mineralocorticoid receptor (MR) from elephant shark, a cartilaginous fish belonging to the oldest group of jawed vertebrates. Based on their measured activities, aldosterone, cortisol, 11-deoxycorticosterone, corticosterone, 11-deoxcortisol, progesterone and 19-norprogesterone are potential physiological mineralocorticoids. However, aldosterone, the physiological mineralocorticoid in humans and other terrestrial vertebrates, is not found in cartilaginous or ray-finned fishes. Because progesterone is a precursor for corticosteroids that activate elephant shark MR, we propose that progesterone was an ancestral ligand for elephant shark MR. Although progesterone activates ray-finned fish MRs, progesterone does not activate human, amphibian or alligator MRs, suggesting that during the transition to terrestrial vertebrates, progesterone lost the ability to activate the MR. Comparison of RNA-sequence analysis of elephant shark MR with that of human MR suggests that MR expression in the human brain, heart, ovary, testis and other non-epithelial tissues evolved in cartilaginous fishes. Together, these data suggest that progesterone-activated MR may have unappreciated functions in elephant shark ovary and testis.
shark steroids; steroid receptor evolution; mineralocorticoid receptor evolution; progesterone; aldosterone; cortisol
Biology and Life Sciences, Anatomy and Physiology
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.
* All users must log in before leaving a comment