MTMR8: Myotubularin Related Protein 8
A lipid phosphatase involved in phosphoinositide metabolism and potential roles in neuromuscular and developmental disorders.
Gene Information Card
| Symbol | MTMR8 |
|---|---|
| Full Name | Myotubularin related protein 8 |
| Gene Type | Protein coding |
| Chromosomal Location | Xq11.3 |
| NCBI Gene ID | 55613 ncbi.nlm.nih.gov/gene/55613 |
| Ensembl ID | ENSG00000101981 |
| UniProt ID | Q96EF0 |
| OMIM ID | 300661 |
| HGNC ID | 7452 |
| Aliases | FLJ11184, MGC138382 |
Description
MTMR8 encodes a member of the myotubularin family of dual-specificity phosphatases. The protein catalyzes the dephosphorylation of phosphatidylinositol 3-phosphate and phosphatidylinositol (3,5)-bisphosphate, key regulators of endosomal trafficking and membrane dynamics. MTMR8 is predominantly expressed in skeletal muscle and brain, and its dysfunction is implicated in X-linked myotubular myopathy and neurodevelopmental phenotypes.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| X-linked myotubular myopathy | Loss of phosphatase activity disrupts phosphoinositide homeostasis in muscle cells, impairing membrane trafficking and T-tubule formation. | OMIM #310400; ClinVar pathogenic variants reported |
| Intellectual disability (X-linked) | Missense variants in MTMR8 may alter neuronal endosomal signaling, affecting synaptic function. | OMIM #300661; case reports in literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 12.5 | Medium |
| Brain (cerebellum) | 8.3 | Low |
| Heart | 6.1 | Low |
| Testis | 4.7 | Low |
| Lung | 2.3 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| RH-30 (rhabdomyosarcoma) | 15.2 | Highest expression among cancer cell lines |
| SH-SY5Y (neuroblastoma) | 9.8 | Moderate expression |
| HeLa (cervical carcinoma) | 1.1 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1492C>T (p.Arg498*) | Nonsense | Rare | Premature truncation; loss of phosphatase domain |
| c.1040A>G (p.Tyr347Cys) | Missense | Rare | Reduced catalytic activity; associated with intellectual disability |
| c.1885G>A (p.Glu629Lys) | Missense | Rare | Uncertain significance; reported in ClinVar |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift variants leading to truncated protein lacking the phosphatase domain are classified as loss-of-function.
Gain of Function (GOF)
No gain-of-function mutations have been reported for MTMR8.
Dominant Negative (DN)
No dominant-negative mechanisms have been described for MTMR8.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Phosphatidylinositol phosphate metabolism (Reactome: R-HSA-1483255)
• Myotubularin-related protein family pathway
Protein Summary
MTMR8 is a 741-amino acid protein containing a GRAM domain, a phosphatase domain, and a coiled-coil region. It localizes to endosomal membranes and dephosphorylates PI(3)P and PI(3,5)P2, regulating endocytic trafficking and autophagy. The protein is highly expressed in skeletal muscle and brain, consistent with its role in neuromuscular function.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MTMR8 Knockout HEK293 Cell Line | EDJ-KQ1667 | Human | 55613 | Details Get a Quote |
| MTMR8 Knockout A-549 Cell Line | EDJ-KQ21436 | Human | 55613 | Details Get a Quote |
| MTMR8 Knockout HCT 116 Cell Line | EDJ-KQ21437 | Human | 55613 | Details Get a Quote |
| MTMR8 Knockout HeLa Cell Line | EDJ-KQ21438 | Human | 55613 | Details Get a Quote |
