ECE2020 Audio ePoster Presentations Reproductive and Developmental Endocrinology (79 abstracts)
1University of Modena and Reggio Emilia, Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Baggiovara, Italy; 2University of Modena and Reggio Emilia, International PhD School in Clinical and Experimental Medicine (CEM), Modena, Italy; 3University of Modena and Reggio Emilia, Center for Genomic Research, Modena, Italy; 4Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany; 5Azienda Ospedaliero-Universitaria di Modena, Department of Medical Specialties, Baggiovara, Italy; 6Centre Inra -Val De Loire, Nouzilly, France
The human luteinizing hormone (LH)/choriogonadotropin (hCG) receptor (LHCGR) discriminates its two hormone ligands. LHCGR differs to the murine receptor (Lhr) in aminoacid residues potentially involved in qualitative discerning of LH and hCG, the latter absent in rodents. We aim to identify LHCGR residues involved in hCG/LH discrimination, indicating evolutionary determinants of human LH/hCG endocrine system. After comparing the LHCGR and Lhr sequences, we developed eight LHCGR cDNAs carrying ‘murinizing’ mutations (R247T; T48R; S149F; I83S; A57T; E270V; N35D and V37A; K225S and T226I) assumed to be interacting specifically with LH, hCG or both. HEK293 cells expressing a mutant or the wild-type receptor were treated by pM-µM LH or hCG concentrations and the kinetics of cAMP and pERK1/2 activation was analysed by BRET. A Lhr-like response was obtained in cells expressing LHCGR carrying the A57T mutation as hCG is more potent than LH in inducing both cAMP (LH EC50 = 0.7 ± 0.2 nM vs hCG EC50 = 0.1 ± 0.03 nM; Mann-Whitney’s U-test; P < 0.05; n = 4; means ±