POMT2
Protein O-Mannosyltransferase 2
Gene Information Card
| Symbol | POMT2 |
|---|---|
| Full Name | Protein O-Mannosyltransferase 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 14q24.3 |
| NCBI Gene ID | 29954 ncbi.nlm.nih.gov/gene/29954 |
| Ensembl ID | ENSG00000100804 |
| UniProt ID | Q9UKY4 |
| OMIM ID | 607439 |
| HGNC ID | 19743 |
| Aliases | LGMD2N, MDDGA2, MDDGB2, MDDGC2 |
Description
POMT2 encodes protein O-mannosyltransferase 2, an integral membrane protein of the endoplasmic reticulum that catalyzes the initial step of O-mannosyl glycosylation. This modification is essential for the proper processing and function of alpha-dystroglycan, a key component of the dystrophin-glycoprotein complex. Mutations in POMT2 cause a spectrum of dystroglycanopathies, ranging from severe congenital muscular dystrophy with brain and eye anomalies (Walker-Warburg syndrome) to milder limb-girdle muscular dystrophy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Walker-Warburg syndrome | Loss of POMT2 function disrupts O-mannosylation of alpha-dystroglycan, impairing basement membrane integrity in muscle, brain, and eye. | OMIM #613150 |
| Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies) type A2 | Biallelic POMT2 mutations lead to severe glycosylation defects. | OMIM #613150 |
| Muscular dystrophy-dystroglycanopathy (congenital without mental retardation) type B2 | Hypomorphic POMT2 variants cause partial loss of glycosylation. | OMIM #613156 |
| Limb-girdle muscular dystrophy type 2N | Milder POMT2 mutations result in late-onset proximal muscle weakness. | OMIM #613158 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 14.2 | Medium |
| Heart | 10.5 | Medium |
| Skeletal muscle | 8.9 | Medium |
| Brain | 6.3 | Low |
| Liver | 3.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 12.4 | Cervical adenocarcinoma |
| HepG2 | 8.7 | Hepatocellular carcinoma |
| K562 | 5.2 | Chronic myeloid leukemia |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1939G>A (p.Gly647Arg) | Missense | Rare | Impaired enzymatic activity; associated with Walker-Warburg syndrome |
| c.1262T>C (p.Leu421Pro) | Missense | Rare | Reduced protein stability; limb-girdle muscular dystrophy |
| c.2167dupA (p.Thr723Asnfs*5) | Frameshift | Rare | Loss of function; severe congenital dystroglycanopathy |
Mutation functional classification
Loss of Function (LOF)
Most POMT2 mutations are loss-of-function, leading to reduced or absent O-mannosyltransferase activity and hypoglycosylation of alpha-dystroglycan.
Gain of Function (GOF)
No gain-of-function mutations have been reported for POMT2.
Dominant Negative (DN)
No dominant-negative effects have been described; POMT2-related disorders are autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • mannosyltransferase activity (GO:0000030) | • protein N-linked glycosylation (GO:0006487) |
| • protein O-linked mannosylation (GO:0006493) | • integral component of membrane (GO:0016021) |
| • endoplasmic reticulum membrane (GO:0005789) |
Pathways
• O-mannosyl glycosylation (Reactome: R-HSA-5173105)
• Dystroglycan-related disorders (KEGG: hsa05310)
Protein Summary
POMT2 is a 746-amino acid transmembrane protein localized to the endoplasmic reticulum. It forms a heteromeric complex with POMT1 to catalyze the transfer of mannose from dolichyl-phosphate-mannose to serine/threonine residues of target proteins, primarily alpha-dystroglycan. This O-mannosylation is critical for the ligand-binding function of alpha-dystroglycan in the extracellular matrix. Loss of POMT2 activity results in hypoglycosylated alpha-dystroglycan, leading to muscular dystrophy and neurodevelopmental defects.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| POMT2 Knockout HEK293 Cell Line | EDJ-KQ9100 | Human | 29954 | Details Get a Quote |
| POMT2 Knockout A-549 Cell Line | EDJ-KQ35600 | Human | 29954 | Details Get a Quote |
| POMT2 Knockout HCT 116 Cell Line | EDJ-KQ35601 | Human | 29954 | Details Get a Quote |
| POMT2 Knockout HeLa Cell Line | EDJ-KQ35602 | Human | 29954 | Details Get a Quote |
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