The KiSS1-derived peptide receptor (also known as GPR54 or the Kisspeptin receptor) is a
G protein-coupled receptor
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related p ...
which binds the peptide hormone
kisspeptin
Kisspeptins (including kisspeptin-54 (KP-54), formerly known as metastin) are proteins encoded by the ''KISS1'' gene in humans. Kisspeptins are ligands of the G-protein coupled receptor, GPR54. ''Kiss1'' was originally identified as a human me ...
(metastin).
Kisspeptin is encoded by the
metastasis suppressor
A metastasis suppressor is a protein that acts to slow or prevent metastases (secondary tumors) from spreading in the body of an organism with cancer. Metastasis is one of the most lethal cancer processes. This process is responsible for about nine ...
gene
KISS1
Kisspeptins (including kisspeptin-54 (KP-54), formerly known as metastin) are proteins encoded by the ''KISS1'' gene in humans. Kisspeptins are ligands of the G-protein coupled receptor, GPR54. ''Kiss1'' was originally identified as a human meta ...
, which is expressed in a variety of endocrine and gonadal tissues.
Activation of the kisspeptin receptor is linked to the
phospholipase C
Phospholipase C (PLC) is a class of membrane-associated enzymes that cleave phospholipids just before the phosphate group (see figure). It is most commonly taken to be synonymous with the human forms of this enzyme, which play an important role ...
and
inositol trisphosphate
Inositol trisphosphate or inositol 1,4,5-trisphosphate abbreviated InsP3 or Ins3P or IP3 is an inositol phosphate signaling molecule. It is made by hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid that is located in the p ...
second messenger cascades inside the cell.
Function
Kisspeptin is involved in the regulation of endocrine function and the onset of
puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. ...
, with activation of the kisspeptin receptor triggering release of
gonadotropin-releasing hormone
Gonadotropin-releasing hormone (GnRH) is a releasing hormone responsible for the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. GnRH is a tropic peptide hormone synthesized and released ...
(GnRH),
and release of kisspeptin itself being inhibited by
oestradiol
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development of f ...
but enhanced by GnRH.
Reductions in kisspeptin levels with age may conversely be one of the reasons behind age-related declines in levels of other endocrine hormones such as
luteinizing hormone
Luteinizing hormone (LH, also known as luteinising hormone, lutropin and sometimes lutrophin) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) ...
.
Ligands
No non-peptide ligands for this receptor have yet been discovered, but as of 2009 both selective agonist and antagonist peptides are known.
Agonists
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Kisspeptin
Kisspeptins (including kisspeptin-54 (KP-54), formerly known as metastin) are proteins encoded by the ''KISS1'' gene in humans. Kisspeptins are ligands of the G-protein coupled receptor, GPR54. ''Kiss1'' was originally identified as a human me ...
(kisspeptin-54, metastin)
* Kisspeptin-10 (112-121 C-terminal fragment)
*
KISS1-305
*
MVT-602 (RVT-602, TAK-448)
*
TAK-683
Antagonists
* Kisspeptin-10 analogues modified with amino substitutions
*
Kisspeptin-234
References
Further reading
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External links
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{{G protein-coupled receptors
G protein-coupled receptors