KiSS-1 Gene Switches on Hormonal Cascade of Puberty

The hormonal surge of puberty (search) may begin with a kiss in more ways than one.

A new study shows that a molecule produced by the aptly named gene KiSS-1 may trigger the hormonal chain of events that primes adolescent boys and girls for their reproductive years.

The findings may help explain how this hormonal system, which is active at birth, becomes dormant during early childhood and then re-emerges with a vengeance for the beginning of adolescence.

"Puberty is critical to human development. And while there is a fairly good understanding of how the endocrine system regulates the hormones involved, just how and when the brain activates this process has been a great mystery," says researcher Tony Plant, PhD, director of the Center for Research in Reproductive Physiology at the University of Pittsburgh School of Medicine, in a news release.

Plant says a better understanding of the biological and brain processes involved in the onset of puberty may eventually help prevent early puberty or treat delayed puberty in some children.

KiSS Triggers Puberty

In the study, which appears in the Feb. 8 edition of Proceedings of the National Academy of Sciences, researchers looked at the role of KiSS-1 in the reproductive system of monkeys, whose reproductive system closely resembles humans'.

Previous studies have suggested that a gene called GPR54 is defective in children with a disorder that delays the start of puberty. The start of puberty is marked by the release of gonadotropin-releasing hormone (GnRH), which stimulates the sex organs (the ovaries or testes) to make the sex hormones.

Based on these findings, researchers looked at the ability of KiSS-1 to turn on GPR54 and stimulate the release of GnRH in adolescent monkeys.

They found that injections of the molecule produced by KiSS-1 triggered a robust release of GnRH in the monkeys.

"We now have very good evidence that the GPR54 gene and its switch, the kisspeptin protein molecule produced by KiSS-1, are key to the initiation of puberty, when GnRH is released," says Plant. "However, it's unlikely that they act alone. Other signaling systems, some of which have probably yet to be identified in humans, help control GnRH release in primates."

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: Shahab, M. Proceedings of the National Academy of Sciences, Feb. 8, 2005; vol 102: pp 2129-2134. News release, University of Pittsburgh Medical Center.