NPFF Neuropeptide FF (FLFQPQRFa) is a mammalian amidated

neuropeptide Neuropeptides are chemical messengers made up of small chains of amino acids that are synthesized and released by neurons. Neuropeptides typically bind to G protein-coupled receptors (GPCRs) to modulate neural activity and other tissues like the ...

originally isolated from bovine brain and characterized as a

pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...

-modulating peptide, with anti-opioid activity on morphine-induced analgesia. In humans, Neuropeptide FF peptides are encoded by the ''NPFF''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. Two genes encoding two different receptors (NPFF1 and NPFF2) and two precursors (NPFFA and NPFFB) have been cloned in several mammalian species.

Function

Neuropeptide FF (NPFF) and RFamide related peptides issued from two precursors interact with good affinity with two subtypes of

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 ...

s, namely NPFF1 and NPFF2 subtypes and are involved in several physiological functions such as cardiovascular regulation, hormonal control, macrophage activation, body temperature

homeostasis In biology, homeostasis (British English, British also homoeostasis) Help:IPA/English, (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physics, physical, and chemistry, chemical conditions maintained by organism, living systems. Thi ...

and pain modulation. Processing of the NPFFA precursor at basic proteolytic sites should generate a NPFF-containing peptide with three additional

N-terminal The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...

amino acids different between species, and a NPSF (SLAAPQRFa)-containing peptide, the length of which depends on the species. NPFFB, identified as a precursor for

RFamide-related peptide The RFamide peptide family, or the RFamide-related peptides (RFRPs), are a family of neuropeptides. They are characterized by the possession of an Arg-Phe-NH2 motif at their C-terminal extremities. Members of the family include: * Neuropeptide FF ...

s (RFRPs, also called GnIH for

gonadotropin inhibitory hormone Gonadotropin-inhibitory hormone (GnIH) is a RFamide-related peptide coded by the ''NPVF'' gene in mammals. Discovery GnIH was discovered in 2000. It is an RFamide peptide that significantly reduced luteinizing hormone release in Coturnix Japonic ...

), contains a LPLRFa-containing peptide and a peptide sharing with NPFF the same C-terminal PQRFamide motif, such as NPVF (VPNLPQRFa) in human. NPFF and

opioid Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid us ...

systems have been shown to interact at several levels, from animal behavior to receptor molecules. Nociception is the physiological function in which this interaction has been the most extensively studied but reward, locomotion, feeding and intestinal motility are also affected.

Endogenous opioid Opioid peptides are peptides that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Such peptides may be produced by the body itself, for example endorphins. The effects of these peptides vary, but th ...

s are necessary for the analgesic properties of spinally injected NPFF while endogenous NPFF peptides are involved in the process of analgesic tolerance/

hyperalgesia Hyperalgesia ( or ; 'hyper' from Greek ὑπέρ (huper, “over”), '-algesia' from Greek algos, ἄλγος (pain)) is an abnormally increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves and can ...

induced by chronic opioid treatment. NPFF also controls the number and metabolic effects of adipose tissue macrophages, and NPFF is necessary for adipose tissue health.

Function

See also

References

Further reading