KissPeptin-10: the reproductive axis switch studied via the GPR54 receptor
An active fragment of the KISS1 protein, this decapeptide is described in the literature as the upstream trigger of pulsatile GnRH secretion.
KissPeptin-10 is a decapeptide corresponding to the active fragment of the KISS1 protein (residues 112-121 of the human sequence). Its discovery profoundly reshaped the academic understanding of upstream regulation of the reproductive axis.
An endogenous agonist of the GPR54 receptor
The peptide is described as the principal endogenous agonist of the G protein-coupled receptor GPR54 (also known as KISS1R). The literature (PMID 16410315) establishes that the KISS1/GPR54 pathway functions as a physiological switch: without functional signaling through this receptor, the gonadotropic axis remains silent in the models studied.
From GnRH to gonadotropins
Upstream in the cascade, GPR54 activation triggers pulsatile GnRH secretion by hypothalamic neurons. Downstream, this pulsatility governs the pituitary release of LH and FSH (PMID 16439435). It is this position as a trigger — rather than an effector — that explains the literature's interest in this peptide as a tool for studying neuroendocrine pulsatility.
Cellular signaling described
At the cellular level, studies (PMID 18202148) report activation of phospholipase C β (PLCβ), an increase in inositol trisphosphate (IP3) and intracellular calcium, as well as induction of c-Fos expression in GnRH neurons — a classic marker of neuronal activation used in immunohistochemistry.
A role described beyond reproduction
The literature (PMID 21653835) also describes an involvement of the kisspeptinergic pathway in puberty regulation, in the coupling between energy status and reproductive function, as well as indirect effects on bone mass via the GH/IGF-1 and corticotropic axes. However, no direct activity on GLP-1, GIP, or GH receptors is reported: specificity for GPR54 remains the dominant trait described.