G protein-coupled receptor-receptor interactions in gonadal physiology.

Background: Gonadotropins are glycoprotein hormones fundamental in the endocrine regulation of reproduction. They act on structurally similar members of G protein-coupled receptors (GPCRs) expressed exclusively in the gonads and support gametogenesis, sex steroid synthesis, and pregnancy. While it is a common opinion that the gonadotropin receptors act as a single molecule entity (monomer), increasing evidence underlines the formation of molecular complexes involving multiple receptors.

Objectives: To review current knowledge of membrane receptor-receptor interactions in reproduction.

Results and discussion: Homo/heteromers of gonadotropin receptors may act as allosteric modulators, act as biased agonist and/or cooperate in sustaining intracellular signals fundamental to support reproduction. Technical limitations lead to in vitro data that require to be confirmed in vivo to figure out the physiological impact of gonadotropin receptor assemblies.

Conclusions: Gonadotropin receptor homo/heteromers provide a new field of research that deserves attention for possible clinical and therapeutic implications in physiology and pathophysiology.