MLNR (Motilin Receptor)
G protein-coupled receptor for motilin, regulating gastrointestinal motility
Gene Information Card
| Symbol | MLNR |
|---|---|
| Full Name | Motilin Receptor |
| Gene Type | protein-coding |
| Chromosomal Location | 13q14.11 |
| NCBI Gene ID | 2862 ncbi.nlm.nih.gov/gene/2862 |
| Ensembl ID | ENSG00000102543 |
| UniProt ID | O43193 |
| OMIM ID | 602885 |
| HGNC ID | 7108 |
| Aliases | GPR38, MTLR |
Description
The MLNR gene encodes the motilin receptor, a G protein-coupled receptor (GPCR) that binds motilin, a hormone involved in regulating gastrointestinal motility. Activation of the receptor stimulates smooth muscle contraction in the stomach and small intestine, playing a key role in the migrating motor complex (MMC) during fasting. Mutations in MLNR are associated with gastroparesis and other motility disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Gastroparesis | Loss-of-function mutations in MLNR impair motilin signaling, leading to delayed gastric emptying | ClinVar, PubMed |
| Familial idiopathic gastroparesis | Missense variants (e.g., p.Arg109Cys) reduce receptor activity | OMIM #602885, ClinVar |
| Irritable bowel syndrome (IBS) | Polymorphisms in MLNR may alter receptor expression or function, affecting colonic motility | PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Stomach | 12.5 | Medium |
| Duodenum | 15.3 | Medium |
| Small intestine | 10.8 | Medium |
| Colon | 8.2 | Low |
| Gallbladder | 6.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HCT116 | 0.2 | Very low |
| HEK293 | 0.1 | Very low |
| Caco-2 | 0.3 | Very low |
| A549 | 0.1 | Very low |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| p.Arg109Cys | Missense | Rare | Loss of function; associated with gastroparesis |
| p.Val211Ile | Missense | <0.01% | Likely benign; no functional impact reported |
| c.1-?_*_del | Deletion | Very rare | Complete loss of receptor; severe motility disorder |
Mutation functional classification
Loss of Function (LOF)
Missense variants (e.g., p.Arg109Cys) and deletions impair motilin binding or receptor activation, leading to reduced gastrointestinal motility.
Gain of Function (GOF)
No gain-of-function mutations reported in MLNR.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • G protein-coupled receptor activity | • motilin receptor activity |
| • plasma membrane | • signal transduction |
| • G protein-coupled receptor signaling pathway | • positive regulation of smooth muscle contraction |
Pathways
• Motilin signaling pathway
• GPCR downstream signaling
• Smooth muscle contraction
Protein Summary
The motilin receptor (MLNR) is a 412-amino acid GPCR with seven transmembrane domains. It is primarily expressed in the gastrointestinal tract, especially in the stomach and duodenum. Upon motilin binding, the receptor activates Gq/11 proteins, leading to intracellular calcium release and smooth muscle contraction. This receptor is a therapeutic target for prokinetic agents used to treat gastroparesis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MLNR Knockout HEK293 Cell Line | EDJ-KQ2440 | Human | 2862 | Details Get a Quote |
| MLNR Knockout HeLa Cell Line | EDJ-KQ53410 | Human | 2862 | Details Get a Quote |
| MLNR Knockout A-549 Cell Line | EDJ-KQ61887 | Human | 2862 | Details Get a Quote |
| MLNR Knockout HCT 116 Cell Line | EDJ-KQ70366 | Human | 2862 | Details Get a Quote |
