MTNR1B
Melatonin Receptor 1B
Gene Information Card
| Symbol | MTNR1B |
|---|---|
| Full Name | Melatonin Receptor 1B |
| Gene Type | protein-coding |
| Chromosomal Location | 11q21-q22 |
| NCBI Gene ID | 4544 ncbi.nlm.nih.gov/gene/4544 |
| Ensembl ID | ENSG00000134640 |
| UniProt ID | P49286 |
| OMIM ID | 600804 |
| HGNC ID | 7465 |
| Aliases | MEL-1B-R, MT2, Mtnr1b |
Description
MTNR1B encodes the melatonin receptor 1B (MT2), a G protein-coupled receptor that binds melatonin, a hormone regulating circadian rhythms and seasonal reproduction. The receptor is primarily expressed in the retina, brain, and pancreatic islets, where it modulates insulin secretion. Common genetic variants in MTNR1B are associated with increased fasting glucose levels and elevated risk of type 2 diabetes.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Type 2 Diabetes | Risk variant rs10830963 increases MTNR1B expression in pancreatic islets, impairing insulin secretion | ClinVar, NCBI |
| Impaired Fasting Glucose | Same variant linked to elevated fasting glucose in multiple GWAS | NCBI, OMIM |
| Gestational Diabetes | MTNR1B variants associated with altered glucose tolerance during pregnancy | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Pancreas | 0.8 | Low |
| Retina | 5.2 | Medium |
| Brain (cerebellum) | 1.1 | Low |
| Pituitary gland | 2.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| INS-1 (rat beta-cell) | N/A | Model for insulin secretion studies |
| HEK293 | N/A | Recombinant expression for functional assays |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| rs10830963 | SNP (intronic) | ~30% (global) | Increased MTNR1B expression, impaired insulin secretion |
| rs1387153 | SNP (intergenic) | ~20% (European) | Associated with fasting glucose and T2D risk |
Mutation functional classification
Loss of Function (LOF)
Rare loss-of-function variants (e.g., frameshift) reduce melatonin signaling, potentially altering circadian glucose regulation.
Gain of Function (GOF)
Common risk alleles (e.g., rs10830963) increase receptor expression, leading to exaggerated melatonin inhibition of insulin release.
Dominant Negative (DN)
Not reported for MTNR1B.
View complete mutation data：
Gene Ontology (GO)
| • G protein-coupled receptor activity | • melatonin receptor activity |
| • circadian rhythm | • insulin secretion |
| • response to light stimulus |
Pathways
• Melatonin signaling pathway
• Circadian entrainment
• GPCR downstream signaling
Protein Summary
The MTNR1B protein (MT2) is a 362-amino acid G protein-coupled receptor with seven transmembrane domains. It couples primarily to Gi/o proteins, inhibiting adenylyl cyclase and reducing cAMP levels upon melatonin binding. MT2 is involved in phase-shifting circadian rhythms and modulating insulin secretion from pancreatic beta-cells.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MTNR1B Knockout HEK293 Cell Line | EDJ-KQ2282 | Human | 4544 | Details Get a Quote |
| MTNR1B Knockout HeLa Cell Line | EDJ-KQ53920 | Human | 4544 | Details Get a Quote |
| MTNR1B Knockout A-549 Cell Line | EDJ-KQ62413 | Human | 4544 | Details Get a Quote |
| MTNR1B Knockout HCT 116 Cell Line | EDJ-KQ70880 | Human | 4544 | Details Get a Quote |
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