protein_function: Relaxin is an ovarian hormone that acts with estrogen toproduce dilatation of the birth canal in many mammals. May beinvolved in remodeling of connective tissues during pregnancy,promoting growth of pubic ligaments and ripening of the cervix.
Relaxins are known endocrine and autocrine,paracrine hormones, belonging to the insulin gene superfamily. In humans there are three non-allelic relaxin genes, RLN1, RLN2 and RLN3, where RLN1 and RLN2 share high sequence homology. The active form of the protein encoded by this gene consists of an A chain and a B chain linked by disulfide bonds. Relaxin is produced by the ovary, and targets the mammalian reproductive system to ripen the cervix, elongate the pubic symphysis and inhibit uterine contraction. It may have additional roles in enhancing sperm motility, regulating blood pressure, controlling heart rate and releasing oxytocin and vasopressin. Relaxin 2(RLN2) is a polypeptide hormone structurally related to insulin and insulin-like growth factors (IGFs). However it does not interact with insulin receptors and has decidedly different biological properties. Relaxin 2 activates LGR 7 and LGR 8 relaxin receptors, that belong to the leucine-rich repeat-containing (LRR), G protein-coupled receptors.
