Regulation of follicle-stimulating and luteinizing hormone receptor signaling by

Follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) belong to the super-family of G protein-coupled receptors (GPCR); GPCRs are negatively regulated by RGS ("regulators of G protein signaling") proteins. In this study we evaluated the effects of RGS3 and RGS10 on FSHR and LHR ligand binding and effector coupling. FSHR and LHR ligand binding were unchanged in the presence of RGS3 or RGS10. However, signaling by FSHR and LHR was diminished by RGS3 but not by RGS10. This constitutes the first demonstration of an interaction between RGS proteins and LH and FSH signaling pathways and identifies a mechanism for negative regulation of RGS3 on FSHR and LHR signaling.