The relaxin receptor LGR7 (RXFP1) is a member of the leucine-rich repeat containing G protein-coupled receptors (GPCR) subgroup C. This and the LGR8 (RXFP2) receptor are unique in having a low-density lipoprotein class A (LDL-A) module at their N termini. This study was designed to show the role of the LDL-A in LGR7 expression and function. Point mutants for the conserved cysteines (Cys⁴⁷ and Cys⁵³) and for calcium binding asparagine (Asp⁵⁸), a mutant with deleted LDL-A domain and chimeric LGR7 receptor with LGR8 LDL-A all showed no cAMP response to human relaxins H1 or H2. We have shown that their cell surface delivery was uncompromised. The mutation of the putative N-linked glycosylation site (Asn³⁶) decreased cAMP production and reduced cell surface expression to 37% of the wild-type (WT) LGR7. All point mutant, chimeric and wild-type receptor proteins were expressed as the two forms. The immature or precursor form of the receptor was 80 kD, whereas the mature receptor, delivered to the cell surface was 95 kD. The glycosylation mutant was also expressed as two forms with appropriately smaller molecular weights. Deletion of the LDL-A module resulted in expression of the mature receptor only. These data suggest that the LDL-A module of LGR7 influences receptor maturation, cell surface expression and relaxin-activated signal transduction.