kisspeptin is a protein that, in humans, has an important role in initiating secretion of the releasing factor gonadotropin-releasing hormone (gnrh). endocrinologists are finding that the protein kisspeptin and its receptor are central to sexual maturation at puberty. if kisspeptin directs the release of gnrh, you can expect that the receptors for kisspeptin will be found in cells of the: posterior pituitary. gonads. anterior pituitary. hypothalamus.