Progesterone receptor A

{{Short description|Isoform of the progesterone receptor}}

The progesterone receptor A (PR-A) is one of three known isoforms of the progesterone receptor (PR), the main biological target of the endogenous progestogen sex hormone progesterone.{{cite journal | vauthors = Jacobsen BM, Horwitz KB | title = Progesterone receptors, their isoforms and progesterone regulated transcription | journal = Mol. Cell. Endocrinol. | volume = 357 | issue = 1–2 | pages = 18–29 | year = 2012 | pmid = 21952082 | pmc = 3272316 | doi = 10.1016/j.mce.2011.09.016 }}{{cite journal | vauthors = Scarpin KM, Graham JD, Mote PA, Clarke CL | title = Progesterone action in human tissues: regulation by progesterone receptor (PR) isoform expression, nuclear positioning and coregulator expression | journal = Nucl Recept Signal | volume = 7 | pages = e009 | year = 2009 | pmid = 20087430 | pmc = 2807635 | doi = 10.1621/nrs.07009 }} The other isoforms of the PR include the PR-B and PR-C.

File:Progesterone Receptor Isoform A.png

PR-A is 164 residues shorter than PR-B in humans{{Cite journal |last1=Graham |first1=J Dinny |last2=Clarke |first2=Christine L |date=October 2002 |title=Progesterone receptors - animal models and cell signaling in breast cancer: Expression and transcriptional activity of progesterone receptor A and progesterone receptor B in mammalian cells |journal=Breast Cancer Research |language=en |volume=4 |issue=5 |pages=187–190 |doi=10.1186/bcr450 |doi-access=free |issn=1465-542X |pmc=138742 |pmid=12223122}} and anywhere from 128-165 residues shorter in other organisms.{{Cite journal |last=Conneely |first=O |date=November 2000 |title=Progesterone receptors in reproduction: functional impact of the A and B isoforms |url=https://linkinghub.elsevier.com/retrieve/pii/S0039128X0000115X |journal=Steroids |volume=65 |issue=10–11 |pages=571–577 |doi=10.1016/S0039-128X(00)00115-X|pmid=11108861 }} Each isoform binds its natural ligand, progesterone, but also demonstrates the ability to bind a number of other agonists including norethindrone, a synthetic progestin.{{Cite journal |last1=Madauss |first1=Kevin P. |last2=Deng |first2=Su-Jun |last3=Austin |first3=Robert J. H. |last4=Lambert |first4=Millard H. |last5=McLay |first5=Iain |last6=Pritchard |first6=John |last7=Short |first7=Steven A. |last8=Stewart |first8=Eugene L. |last9=Uings |first9=Ian J. |last10=Williams |first10=Shawn P. |date=2004-06-01 |title=Progesterone Receptor Ligand Binding Pocket Flexibility: Crystal Structures of the Norethindrone and Mometasone Furoate Complexes |url=https://pubs.acs.org/doi/10.1021/jm030640n |journal=Journal of Medicinal Chemistry |language=en |volume=47 |issue=13 |pages=3381–3387 |doi=10.1021/jm030640n |pmid=15189034 |issn=0022-2623}}

File:Dimerized Progesterone Receptor Bound to Norethindrone 20250509.png