Metastasis suppressor protein. May regulate events downstream of cell-matrix adhesion, perhaps involving cytoskeletal reorganization. Generates a C-terminally amidated peptide, metastin which functions as the endogenous ligand of the G-protein coupled receptor GPR54. The receptor is also essential for normal gonadotropin-released hormone physiology and for puberty. The hypothalamic KiSS1/GPR54 system is a pivotal factor in central regulation of the gonadotropic axis at puberty and in adulthood. Intracerebroventricular administration induces an increase in serum LH and FSH levels in prepubertal male and female as well as in adult animals