Kisspeptin is a small protein that talks to a receptor called GPR54 and helps control the whole reproductive system, from brain signals that start puberty to hormone release and even sperm activity. Changes in the kisspeptin gene or its receptor can cause delayed puberty or early puberty, and higher kisspeptin levels in blood can signal early puberty. The study mainly explains how this system works and why it matters for reproductive health.

Kisspeptin is a 54- amino acid peptide that acts as a ligand of a receptor called GPR54 which is basically a transmembrane receptor that spins seven times across the cell membrane and coupled with G-protein. Kisspeptin regulates the development of reproductive functions and the onset of puberty in human and other mammals by acting at the brain, hypothalamus, pituitary and gonad levels of reproductive axis. Kisspeptin is also involved in regulation of trophoblastic invasion during pregnancy, ovulation, and sperm hyperactivation. Inactivating mutations in human kisspeptin gene (KISS1) cause idiopathic hypogonadotropic hypogonadism. Some mutations in human kisspeptin receptor gene (KISS1R) make the receptor inactive which result in idiopathic hypogonadotropic hypogonadism. Some mutations in human KISS1R gene make the receptor prematurely activated and result in the development of central precocious puberty. Central precocious puberty is also caused by some mutations in human KISS1 gene that make the kisspeptin resistant to degradation. This leads to an increased basal kisspeptin level and subsequently the development of central precocious puberty. Higher kisspeptin level has been detected in the serum and plasma of central precocious puberty patients, which suggest that serum or plasma kisspeptin level can be used as a marker for diagnosis of central precocious puberty.