MTMR9: Myotubularin Related Protein 9
A regulatory subunit of the myotubularin phosphatase family involved in phosphoinositide metabolism and vesicular trafficking.
Gene Information Card
| Symbol | MTMR9 |
|---|---|
| Full Name | Myotubularin Related Protein 9 |
| Gene Type | Protein coding |
| Chromosomal Location | 8p23.1 |
| NCBI Gene ID | 66036 ncbi.nlm.nih.gov/gene/66036 |
| Ensembl ID | ENSG00000104419 |
| UniProt ID | Q96G74 |
| OMIM ID | 611289 |
| HGNC ID | 26197 |
| Aliases | C8orf9, FLJ14675, MTMR8 |
Description
MTMR9 (Myotubularin Related Protein 9) encodes a protein that belongs to the myotubularin family of phosphoinositide phosphatases. Unlike the catalytic members, MTMR9 lacks phosphatase activity and functions as a regulatory subunit. It forms heterodimers with catalytically active myotubularins (e.g., MTMR6, MTMR7, MTMR8) to modulate their activity and substrate specificity. The protein is involved in phosphatidylinositol 3-phosphate (PI3P) and phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) metabolism, impacting endosomal trafficking, autophagy, and cell signaling.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Obesity (susceptibility) | MTMR9 variants may alter phosphoinositide signaling affecting energy homeostasis and adipocyte function. | GWAS studies (PMID: 19629071) |
| Type 2 diabetes (susceptibility) | Potential link through obesity-related metabolic pathways. | Association studies (PMID: 19629071) |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Adipose tissue | 8.3 | Low |
| Liver | 6.1 | Low |
| Skeletal muscle | 9.7 | Low |
| Kidney | 7.4 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 10.2 | Embryonic kidney cells |
| HeLa | 8.9 | Cervical carcinoma cells |
| SH-SY5Y | 14.1 | Neuroblastoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| rs2293855 (c.101C>T) | Missense (p.Thr34Met) | 0.15 (East Asian) | Alters protein interaction; associated with obesity risk |
| rs3748034 (c.463G>A) | Missense (p.Val155Ile) | 0.08 (European) | Unknown functional effect |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in ClinVar or COSMIC.
Gain of Function (GOF)
Not described.
Dominant Negative (DN)
Not described.
View complete mutation data：
Gene Ontology (GO)
Pathways
• ['Phosphatidylinositol phosphate metabolism (Reactome: R-HSA-1483255)']
• ['Autophagy (Reactome: R-HSA-9612973)']
• ['Endosomal trafficking (Reactome: R-HSA-199991)']
Protein Summary
MTMR9 is a 549-amino acid protein that acts as a catalytically inactive scaffold for active myotubularin phosphatases. It contains a coiled-coil domain mediating heterodimerization and a GRAM domain for membrane targeting. The protein regulates PI3P and PI(3,5)P2 levels, crucial for endosomal maturation and autophagy. Its expression is highest in brain and neuroblastoma cells, suggesting a role in neuronal vesicle dynamics.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MTMR9 Knockout HEK293 Cell Line | EDJ-KQ14331 | Human | 66036 | Details Get a Quote |
| MTMR9 Knockout A-549 Cell Line | EDJ-KQ44436 | Human | 66036 | Details Get a Quote |
| MTMR9 Knockout HCT 116 Cell Line | EDJ-KQ44437 | Human | 66036 | Details Get a Quote |
| MTMR9 Knockout HeLa Cell Line | EDJ-KQ44438 | Human | 66036 | Details Get a Quote |
