Enables hormone binding activity. Acts upstream of or within several processes, including lung connective tissue development; nipple morphogenesis; and parturition. Predicted to be located in plasma membrane. Predicted to be integral component of membrane. Predicted to be integral component of plasma membrane. Is expressed in brain and metanephros. Orthologous to human RXFP1 (relaxin family peptide receptor 1). [provided by Alliance of Genome Resources, Apr 2022]