Metastasis suppressor protein in malignant melanomas and in some breast cancers. 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. Activation of the receptor inhibits cell proliferation and cell migration, key characteristics of tumor metastasis. Kp-1 is a decapeptide derived from the primary translation product, isolated in conditioned medium of first trimester trophoblast. Kp-1, but not other kisspeptins, increased intracellular Ca(2+) levels in isolated first trimester trophoblasts. Kp-1 is a paracrine/endocrine regulator in fine-tuning trophoblast invasion generated by the trophoblast itself. 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.
