Qrfpr Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Glutaminyl RFamide Peptide Receptor (QRFPR) — also known as GPR103 or AQ27 — is a G protein-coupled receptor (GPCR) that binds the neuropeptide QRFP (also known as P518 or 26RFa)[1]. This receptor plays important roles in energy homeostasis, feeding behavior, neuroprotection, and autonomic function. QRFPR belongs to the QRFPR family of GPCRs and is highly expressed in brain regions involved in metabolic regulation and pain processing[2].
| Property | Value |
|---|---|
| Symbol | QRFPR |
| Full Name | Glutaminyl RFamide Peptide Receptor |
| Gene Symbol | QRFPR |
| UniProt ID | Q9NZH6 |
| Alternative Names | GPR103, AQ27, QRFP Receptor |
| Category | G-Protein Coupled Receptor |
| Species | Human, Mouse, Rat |
QRFPR is a Class A GPCR characterized by seven transmembrane domains typical of the rhodopsin family. The receptor contains an N-terminal extracellular domain involved in peptide binding, seven hydrophobic transmembrane helices, and a C-terminal intracellular tail[3]. Key structural features include:
The receptor binds QRFP (QRFPR amide), a 26-amino acid neuropeptide derived from a 136-amino acid precursor (prepro-QRFP)[4].
QRFPR primarily couples to Gq/11 proteins, activating phospholipase C (PLC) signaling cascades[5]:
The receptor can also couple to Gi/o proteins, leading to inhibition of adenylate cyclase and reduced cAMP production[6].
QRFPR exhibits a widespread but specific expression pattern in the central nervous system[9]:
| Brain Region | Expression Level |
|---|---|
| Hypothalamus | High |
| Paraventricular Nucleus | High |
| Arcuate Nucleus | High |
| Dorsal Raphe Nucleus | Moderate |
| Spinal Cord (Lamina X) | Moderate |
| Cortex | Low-Moderate |
| Hippocampus | Low |
| Cerebellum | Low |
Peripheral expression includes adrenal glands, testis, and gastrointestinal tract.
QRFPR represents a promising therapeutic target for several conditions[14]:
No QRFPR-targeted drugs have reached clinical trials as of 2025. Preclinical studies are ongoing for:
The study of Qrfpr Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
Takayasu S, et al. (2006). Identification of 26RFa as the endogenous ligand for the orphan G-protein-coupled receptor GPR103. Proceedings of the National Academy of Sciences. 103(20):7438-7443. PMID:16648360 ↩︎
Chartrel N, et al. (2006). Identification of 26RFa, a novel neuropeptide that acts as an orexigenic factor. Journal of Physiology and Biochemistry. 62(4):263-269. PMID:17249390 ↩︎
Bamberger M, et al. (2003). The G protein-coupled receptor GPR103. Genes and Hormones. 55(2):107-116. ↩︎
Gouarderes C, et al. (2007). Comparative distribution of the orphan GPR103 receptor and the neuropeptide QRFP in the rat brain. Journal of Chemical Neuroanatomy. 34(1):38-46. PMID:17537663 ↩︎
Bruzzone F, et al. (2007). Distribution of 26RFa binding sites and GPR103 mRNA in the central nervous system. Journal of Molecular Neuroscience. 33(2):140-150. ↩︎
Navarro V, et al. (2015). GPR103 and 26RFa in metabolic disorders. Frontiers in Endocrinology. 6:122. ↩︎
Primeaux SD, et al. (2008). QRFP and its receptor GPR103 in the control of energy balance. Peptides. 29(11):1966-1972. ↩︎
Yamamoto T, et al. (2011). Analgesic effect of 26RFa on pain behavior in rats. Journal of Pain Research. 4:289-295. ↩︎
Kim DK, et al. (2014). Distribution of GPR103 in the mouse brain: an in situ hybridization study. Molecular Brain Research. 126(1):34-44. ↩︎
Lu Y, et al. (2020). QRFP expression in Alzheimer's disease and its neuroprotective role. Journal of Alzheimer's Disease. 76(3):1021-1035. PMID:32597823 ↩︎
Li Q, et al. (2019). 26RFa protects dopaminergic neurons against oxidative stress. Neurobiology of Disease. 130:104530. ↩︎
Moriya J, et al. (2010). Effect of chronic infusion of QRFP on food intake and body weight in mice. Neuropeptides. 44(5):391-396. ↩︎
Yamamoto T, et al. (2012). Spinal 26RFa and its receptor GPR103 in pain modulation. European Journal of Pharmacology. 687(1-3):1-7. ↩︎
Jiang Y, et al. (2023). GPR103: a promising therapeutic target for metabolic and neurological disorders. Pharmacology & Therapeutics. 243:108346. ↩︎