The Cloned Equine Thyrotropin Receptor Is Hypersensitive to Human Chorionic Gonadotropin; Identification of Three Residues in the Extracellular Domain Involved in Ligand Specificity

TitreThe Cloned Equine Thyrotropin Receptor Is Hypersensitive to Human Chorionic Gonadotropin; Identification of Three Residues in the Extracellular Domain Involved in Ligand Specificity
Type de publicationArticle de revue
AuteurRoyer, Julien, Lefevre-Minisini, Anne, Caltabiano, Gianluigi, Lacombe, Thierry, Malthièry, Yves
1, 2
, Savagner, Frédérique
1, 2
, Pardo, Leonardo, Rodien, Patrice
EditeurEndocrine Society
TypeArticle scientifique dans une revue à comité de lecture
Année2008
LangueAnglais
Date2008/01/10
Numéro10
Pagination5088 - 5096
Volume149
Titre de la revueEndocrinology
ISSN0013-7227, 1945-7170
Résumé en anglais

The receptors for TSH, LH/chorionic gonadotropin (CG), and FSH belong to the same subfamily of G protein-coupled receptors. The specificity of recognition of their cognate hormone involves a limited number of residues in the leucine-rich repeats present in the N-terminal ectodomain of the receptor. It is admitted that receptors of this subfamily coevoluted with their respective ligands. The secretion of CG is restricted to gestation of primates and Equidae. We hypothesized that, facing the challenge of a new hormone, the glycoprotein hormone receptors would have evolved differently in Equidae and human so that distinct residues are involved in hormone specificity. In particular, it is known that equine CG has a dual (FSH and LH) activity when administered to other species. In the present work, we cloned and characterized functionally the equine TSH receptor (TSHR), which shares 89% homology with the human TSHR. The equine TSHR is not responsive to equine CG but is more sensitive to human CG than the human TSHR. Three residues, at positions 60, 229, and 235 of the ectodomain, are responsible for this difference in sensitivity as shown by modelization and targeted mutagenesis, followed by in vitro functional characterization. The phylogenetic approach is a suitable approach to identify determinants of specificity of receptors.

URL de la noticehttp://okina.univ-angers.fr/publications/ua354
DOI10.1210/en.2008-0423
Lien vers le document

http://dx.doi.org/10.1210/en.2008-0423