TPM2 Gene - Tropomyosin 2
Essential regulator of actin filament stability in muscle and non-muscle cells
Gene Information Card
| Symbol | TPM2 |
|---|---|
| Full Name | tropomyosin 2 |
| Gene Type | protein coding |
| Chromosomal Location | 9p13.3 |
| NCBI Gene ID | 7169 ncbi.nlm.nih.gov/gene/7169 |
| Ensembl ID | ENSG00000198467 |
| UniProt ID | P07951 |
| OMIM ID | 190990 |
| HGNC ID | 12011 |
| Aliases | AMCD1, DA1, NEM4, TMSB, tropomyosin beta chain |
Description
The TPM2 gene encodes the beta chain of tropomyosin, a coiled-coil actin-binding protein that stabilizes actin filaments and regulates actin-myosin interaction in muscle and non-muscle cells. Alternative splicing generates multiple isoforms with tissue-specific expression. Mutations in TPM2 are associated with nemaline myopathy type 4, cap myopathy, and distal arthrogryposis type 1.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Nemaline myopathy 4 | Missense or nonsense mutations disrupt actin binding or filament stability, leading to nemaline rod formation | ClinVar, OMIM #609285 |
| Cap myopathy | Dominant-negative mutations impair sarcomere assembly, causing cap-like structures at myofiber periphery | ClinVar, OMIM #609284 |
| Distal arthrogryposis type 1 | Missense mutations alter tropomyosin conformation, reducing muscle contractility and causing joint contractures | OMIM #108120 |
| Arthrogryposis multiplex congenita | Loss-of-function variants lead to severe congenital joint contractures | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 267.5 | High |
| Heart | 98.3 | Medium |
| Smooth muscle | 45.2 | Medium |
| Brain | 1.8 | Low |
| Liver | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Skeletal muscle myoblasts | 312.0 | High expression in differentiated myotubes |
| Cardiomyocytes | 112.4 | Moderate expression |
| Fibroblasts | 8.3 | Low expression |
| HEK 293 | 2.1 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.502G>A (p.Glu168Lys) | Missense | Rare | Dominant-negative; disrupts tropomyosin-actin binding |
| c.463G>A (p.Glu155Lys) | Missense | Rare | Associated with cap myopathy |
| c.1A>G (p.Met1?) | Start loss | Rare | Loss of function; leads to nemaline myopathy |
| c.574C>T (p.Arg192*) | Nonsense | Rare | Premature stop; loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations (e.g., p.Arg192*) reduce tropomyosin levels, impairing actin filament stability.
Gain of Function (GOF)
Not reported for TPM2.
Dominant Negative (DN)
Missense mutations (e.g., p.Glu168Lys, p.Glu155Lys) produce altered protein that interferes with wild-type tropomyosin function, causing cap myopathy or nemaline myopathy.
View complete mutation data：
Gene Ontology (GO)
| • actin binding (GO:0003779) | • tropomyosin binding (GO:0005523) |
| • muscle contraction (GO:0006936) | • muscle filament sliding (GO:0030049) |
| • actin filament stabilization (GO:0051015) |
Pathways
• Muscle contraction (Reactome: R-HSA-397014)
• Striated muscle contraction (Reactome: R-HSA-390522)
• Smooth muscle contraction (Reactome: R-HSA-445355)
Protein Summary
Tropomyosin 2 (TPM2) is a 284-amino acid protein that forms a coiled-coil dimer and binds along the actin filament. It stabilizes actin filaments and regulates myosin head access during muscle contraction. Mutations in TPM2 disrupt sarcomere integrity, leading to congenital myopathies and arthrogryposis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TPM2 Knockout HEK293 Cell Line | EDJ-KQ15895 | Human | 7169 | Details Get a Quote |
| TPM2 Knockout A-549 Cell Line | EDJ-KQ49115 | Human | 7169 | Details Get a Quote |
| TPM2 Knockout HCT 116 Cell Line | EDJ-KQ49116 | Human | 7169 | Details Get a Quote |
| TPM2 Knockout HeLa Cell Line | EDJ-KQ49117 | Human | 7169 | Details Get a Quote |
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