RFamide peptide family

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The RFamide peptide family, or the RFamide-related peptides (RFRPs), are a family of neuropeptides. [1] [2] They are characterized by the possession of an Arg-Phe-NH2 motif at their C-terminal extremities. [1] [2]

Members of the family include: [1] [2]

See also

Related Research Articles

Peptides are short chains of amino acids linked by peptide bonds. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides.

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 gut, muscles, and heart.

FMRFamide Chemical compound

FMRFamide (H-Phe-Met-Arg-Phe-NH2) is a neuropeptide from a broad family of FMRFamide-related peptides (FaRPs) all sharing an -RFamide sequence at their C-terminus. First identified in Hard clam, it is thought to play an important role in cardiac activity regulation. Several FMRFamide related peptides are known, regulating various cellular functions and possessing pharmacological actions, such as anti-opiate effects. In Mercenaria mercenaria, FMRFamide has been isolated and demonstrated to increase both the force and frequency of the heartbeat through a biochemical pathway that is thought to involve the increase of cytoplasmic cAMP in the ventricular region.

Signaling peptide receptor is a type of receptor which binds one or more signaling peptides or signaling proteins.

CLIP (protein)

CLIP or Class II-associated invariant chain peptide is the part of the invariant chain (Ii) that binds to the peptide binding groove of MHC class II and remains there until the MHC receptor is fully assembled. CLIP is one of the most prevalent self peptides found in the thymic cortex of most antigen-presenting cells. The purpose of CLIP is to prevent the degradation of MHC II dimers before antigenic peptides bind, and to prevent autoimmunity.

Kisspeptin

Kisspeptins 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 metastasis suppressor gene that has the ability to suppress melanoma and breast cancer metastasis. Kisspeptin-GPR54 signaling has an important role in initiating secretion of gonadotropin-releasing hormone (GnRH) at puberty, the extent of which is an area of ongoing research. Gonadotropin-releasing hormone is released from the hypothalamus to act on the anterior pituitary triggering the release of luteinizing hormone (LH), and follicle stimulating hormone (FSH). These gonadotropic hormones lead to sexual maturation and gametogenesis. Disrupting GPR54 signaling can cause hypogonadotrophic hypogonadism in rodents and humans. The Kiss1 gene is located on chromosome 1. It is transcribed in the brain, adrenal gland, and pancreas.

Neurokinin B Chemical compound

Neurokinin B (NKB) belongs in the family of tachykinin peptides. Neurokinin B is implicated in a variety of human functions and pathways such as the secretion of gonadotropin-releasing hormone. Additionally, NKB is associated with pregnancy in females and maturation in young adults. Reproductive function is highly dependent on levels of both neurokinin B and also the G-protein coupled receptor ligand kisspeptin. The first NKB studies done attempted to resolve why high levels of the peptide may be implicated in pre-eclampsia during pregnancy. NKB, kisspeptin, and dynorphin together are found in the arcuate nucleus (ARC) known as the KNDy subpopulation. This subpopulation is targeted by many steroid hormones and works to form a network that feeds back to GnRH pulse generator.

KiSS1-derived peptide receptor

The KiSS1-derived peptide receptor is a G protein-coupled receptor which binds the peptide hormone kisspeptin (metastin). Kisspeptin is encoded by the metastasis suppressor gene KISS1, which is expressed in a variety of endocrine and gonadal tissues. Activation of the kisspeptin receptor is linked to the phospholipase C and inositol trisphosphate second messenger cascades inside the cell.

The neuropeptide FF receptors are members of the G-protein coupled receptor superfamily of integral membrane proteins which bind the pain modulatory neuropeptides AF and FF. The Neuropeptide FF receptor family is a member of the G protein-coupled receptor superfamily containing two subtypes, NPFF1 and NPFF2, which exhibit a high affinity for Neuropeptide FF (NPFF) peptides. NPFF1 is broadly distributed in the central nervous system with the highest levels found in the limbic system and the hypothalamus. NPFF2 is present in high density, particularly in mammals in the superficial layers of the spinal cord where it is involved in nociception and modulation of opioid functions. These receptors participate to the modulation of opioid receptor function in the brain and spinal cord, and can either reduce or increase opioid receptor function depending which tissue they are released in, reflecting a complex role for neuropeptide FF in pain responses.

Neuropeptide FF receptor 2

Neuropeptide FF receptor 2, also known as NPFF2 is a human protein encoded by the NPFFR2 gene.

Neuropeptide FF receptor 1

Neuropeptide FF receptor 1, also known as NPFF1 is a human protein, encoded by the NPFFR1 gene.

Pyroglutamylated RFamide peptide receptor

Pyroglutamylated RFamide peptide receptor also known as orexigenic neuropeptide QRFP receptor or G-protein coupled receptor 103 (GPR103) is a protein that in humans is encoded by the QRFPR gene.

Neuropeptide FF

NPFF Neuropeptide FF (FLFQPQRFa) is a mammalian amidated neuropeptide originally isolated from bovine brain and characterized as a pain-modulating peptide, with anti-opioid activity on morphine-induced analgesia.

QRFP

RF(Arg-Phe)amide family 26 amino acid peptide, also known as P518, is a human protein.

BIBP-3226

BIBP-3226 is a drug used in scientific research which acts as a potent and selective antagonist for both the Neuropeptide Y receptor Y1 and also the neuropeptide FF receptor. It was the first non-peptide antagonist developed for the Y1 receptor and has been widely used to help determine its functions in the body. Activation of Y1 is thought to be involved in functions such as regulation of appetite and anxiety, and BIBP-3226 has anxiogenic and anorectic effects, as well as blocking the Y1-mediated corticotropin releasing hormone release. It has also been used as a lead compound to develop a number of newer more potent Y1 antagonists.

Valorphin Chemical compound

Valorphin, also known as VV-hemorphin-5, is a naturally occurring, endogenous opioid heptapeptide of the hemorphin family with the amino acid sequence H-Val-Val-Tyr-Pro-Trp-Thr-Gln-OH (VVYPWTQ). It is produced in the body via proteolyic cleavage of residues 33-39 of the β-chain of hemoglobin. Valorphin binds preferentially to the μ-opioid receptor and produces effects such as analgesia and self-administration in animals. It also possesses cytotoxic and antiproliferative properties against tumor cells, the mediation of which, because they are reversed by naloxone, appears to be dependent on the opioid receptors.

<i>beta</i>-Melanocyte-stimulating hormone Chemical compound

β-Melanocyte-stimulating hormone (β-MSH) is an endogenous peptide hormone and neuropeptide. It is a melanocortin, specifically, one of the three types of melanocyte-stimulating hormone (MSH), and is produced from proopiomelanocortin (POMC). It is an agonist of the MC1, MC3, MC4, and MC5 receptors.

γ-Melanocyte-stimulating hormone (γ-MSH) is an endogenous peptide hormone and neuropeptide. It is a melanocortin, specifically, one of the three types of melanocyte-stimulating hormone (MSH), and is produced from proopiomelanocortin (POMC). It is an agonist of the MC1, MC3, MC4, and MC5 receptors. It exists in three forms, γ1-MSH, γ2-MSH, and γ3-MSH.

Neuropeptide VF precursor, also known as pro-FMRFamide-related neuropeptide VF or RFamide-related peptide precursor, is a propeptide that in mammals is encoded by the NPVF (or RPFP) gene. The NPVF gene, and thus the propeptide, are expressed in neurons in the mediobasal hypothalamus. The propeptide is cleaved to form three other peptides, which are:

References

  1. 1 2 3 Abba Kastin; Abba J. Kastin (28 April 2011). Handbook of Biologically Active Peptides. Academic Press. pp. 779–. ISBN   978-0-08-046379-7.
  2. 1 2 3 Findeisen, Maria; Rathmann, Daniel; Beck-Sickinger, Annette G. (2011). "RFamide Peptides: Structure, Function, Mechanisms and Pharmaceutical Potential". Pharmaceuticals. 4 (9): 1248–1280. doi: 10.3390/ph4091248 . ISSN   1424-8247. PMC   4058657 .
  3. Yun S, Kim DK, Furlong M, Hwang JI, Vaudry H, Seong JY (2014). "Does Kisspeptin Belong to the Proposed RF-Amide Peptide Family?". Front Endocrinol (Lausanne). 5: 134. doi: 10.3389/fendo.2014.00134 . PMC   4131245 . PMID   25165463.