MYH2: Myosin Heavy Chain 2 – Skeletal Muscle Gene
Essential for fast-twitch muscle contraction; mutations cause myopathy and arthrogryposis
Gene Information Card
| Symbol | MYH2 |
|---|---|
| Full Name | myosin heavy chain 2 |
| Gene Type | protein coding |
| Chromosomal Location | 17p13.1 |
| NCBI Gene ID | 4620 ncbi.nlm.nih.gov/gene/4620 |
| Ensembl ID | ENSG00000125414 |
| UniProt ID | Q9UKX2 |
| OMIM ID | 160740 |
| HGNC ID | 7572 |
| Aliases | MYH2A, MYHSA2, MyHC-2A, MyHC-IIa |
Description
MYH2 (myosin heavy chain 2) encodes the heavy chain of myosin IIa, a major contractile protein in fast-twitch (type 2A) skeletal muscle fibers. It is essential for muscle contraction, ATP hydrolysis, and actin binding. Mutations in MYH2 cause autosomal dominant or recessive myopathies, including inclusion body myopathy with early-onset joint contractures (arthrogryposis) and progressive muscle weakness.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Inclusion body myopathy with early-onset joint contractures (arthrogryposis) | Loss-of-function mutations impair myosin filament assembly, reducing contractile force and causing muscle degeneration | ClinVar, OMIM #605637 |
| Myopathy, proximal, with early respiratory failure | Dominant-negative mutations disrupt sarcomere structure, leading to progressive weakness | OMIM #160740 |
| Distal myopathy, MYH2-related | Missense variants alter ATPase activity, impairing muscle relaxation and causing distal weakness | ClinVar, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 58.2 | High |
| Heart | 1.3 | Low |
| Esophagus | 0.8 | Low |
| Brain | 0.1 | Not detected |
| Liver | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Skeletal muscle myoblasts | 62.5 | High expression in differentiated myotubes |
| Rhabdomyosarcoma cells (RD) | 45.0 | Cancer cell line with muscle lineage |
| Fibroblasts | 0.2 | No significant expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1327C>T (p.Arg443Trp) | Missense | Rare | Dominant-negative; disrupts actin binding |
| c.4522delC (p.Leu1508Trpfs*12) | Frameshift | Very rare | Loss-of-function; causes myopathy with arthrogryposis |
| c.1393G>A (p.Glu465Lys) | Missense | Rare | Impaired ATPase activity; distal myopathy |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations lead to truncated myosin heavy chain, causing haploinsufficiency or nonsense-mediated decay, resulting in muscle weakness and joint contractures.
Gain of Function (GOF)
Not reported for MYH2; gain-of-function is not a known mechanism.
Dominant Negative (DN)
Missense mutations (e.g., p.Arg443Trp) produce defective myosin that interferes with wild-type filament assembly, causing dominant myopathy.
View complete mutation data：
Gene Ontology (GO)
| • motor activity (GO:0003774) | • ATP binding (GO:0005524) |
| • calmodulin binding (GO:0005516) | • myosin complex (GO:0016459) |
| • muscle filament sliding (GO:0030049) | • muscle contraction (GO:0006936) |
Pathways
• Smooth muscle contraction (Reactome R-HSA-445355)
• Striated muscle contraction (Reactome R-HSA-390522)
• Cardiac muscle contraction (KEGG hsa04260)
Protein Summary
MYH2 encodes the myosin heavy chain 2A (MyHC-2A), a 200 kDa protein that forms the thick filament of sarcomeres in fast-twitch skeletal muscle. It contains an N-terminal motor domain with ATPase activity, a neck region with light chain binding sites, and a C-terminal tail that mediates filament assembly. The protein is critical for generating contractile force and is highly expressed in type 2A fibers. Mutations lead to structural defects in sarcomeres, causing myopathies characterized by weakness, contractures, and respiratory failure.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MYH2 Knockout HEK293 Cell Line | EDJ-KQ3690 | Human | 4620 | Details Get a Quote |
| MYH2 Knockout HeLa Cell Line | EDJ-KQ53938 | Human | 4620 | Details Get a Quote |
| MYH2 Knockout A-549 Cell Line | EDJ-KQ62431 | Human | 4620 | Details Get a Quote |
| MYH2 Knockout HCT 116 Cell Line | EDJ-KQ70898 | Human | 4620 | Details Get a Quote |
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