Receptor for metastin, a C-terminally amidated peptide of KiSS1. KiSS1 is a metastasis suppressor protein. Activation of the receptor inhibits cell proliferation and cell migration, key characteristics of tumor metastasis. The receptor is essential for normal gonadotropin-released hormone physiology and for puberty. The hypothalamic KiSS1/KISS1R system is a pivotal factor in central regulation of the gonadotropic axis at puberty and in adulthood. Analysis of the transduction pathways activated by the receptor identifies coupling to phospholipase C and intracellular calcium release through pertussis toxin-insensitive G(q) proteins. Highest expression levels in the cerebrum and cecum. Moderate expression in the ovary, colon and placenta. Low levels in the uterus, small intestine, and thymus. Expressed only moderately in the placenta. No expression in kidney tissues. Has a complex and abundant central nervous system expression pattern. Expressed in brain regions such as pons, midbrain, thalamus, hypothalamus, hippocampus, amygdala, cortex, frontal cortex, and striatum. No expression in the cerebellum. Persistent expression is detected in hypothalamus throughout postnatal development, with maximum expression levels at puberty in both male and female. Hypothalamic expression changed throughout the estrus cycle and is significantly increased after gonadectomy, a rise that is prevented by sex steroid replacement both in males and females. Expression detected in trophoblast giant cells (TGCs), the placenta-derived cell lineage aligned at the boundary between the uterus and placenta, at embryonic days 12.5 (E12.5). However, expression is faint and only observed in some of these cells, and disappears by E15.5. Belongs to the G-protein coupled receptor 1 family.