[Structural-functional organization of polypeptide hormones receptors containing LRR-repeats and their interaction with heterotrimeric G proteins].

The data on structural-functional organization of the serpentine type receptors containing LRR-repeats termed LGR receptors were summarized and analyzed. These receptors include the receptors of pituitary glycoprotein hormones (gonadotropins and thyrotropin) and the relaxin receptors RXFP1 and RXFP2. The mechanisms of the activation of the receptors by the hormones, and molecular basis of interaction between the receptors and heterotrimeric G proteins were considered. The role of membrane-proximal regions of cytoplasmic loops of the receptors and adjacent segments of transmembrane regions in the formation of G protein-binding surface of the receptor and in the activation of the G proteins are discussed. On the basis of literature data and our results, the molecular determinants responsible for selectivity and efficiency of interactions with the G proteins were detected in the LGR-receptors.