The relaxin receptor (RXFP1) utilizes hydrophobic moieties on a signaling surface of its N-terminal low density lipoprotein class A module to mediate receptor activation

Background: Activation of the relaxin receptor RXFP1 is driven by the LDLa module at the RXFP1 N terminus. Results: LDLa residues Leu-7, Tyr-9, and Lys-17 all contribute to receptor activation via interactions involving their hydrophobic side chains. Conclusion: These interactions induce the active receptor conformation, suggesting a novel mode of GPCR activation. Significance: This novel mechanism of GPCR activation may lead to new drug development.