TPM3 Gene: Tropomyosin 3
Key regulator of actin filament stability in muscle and non-muscle cells; associated with nemaline myopathy and cancer
Gene Information Card
| Symbol | TPM3 |
|---|---|
| Full Name | tropomyosin 3 |
| Gene Type | protein coding |
| Chromosomal Location | 1q21.3 |
| NCBI Gene ID | 7170 ncbi.nlm.nih.gov/gene/7170 |
| Ensembl ID | ENSG00000143549 |
| UniProt ID | P06753 |
| OMIM ID | 191030 |
| HGNC ID | 12012 |
| Aliases | TM3, TM-3, TM30, TPM3mu, TPM3nu, NEM1, CFTD, CAPM1 |
Description
The TPM3 gene encodes tropomyosin 3, an actin-binding protein that stabilizes actin filaments and regulates muscle contraction. It is expressed in both muscle and non-muscle tissues. Mutations in TPM3 are associated with nemaline myopathy type 1 (NEM1), congenital fiber-type disproportion (CFTD), and cap myopathy (CAPM1). Somatic mutations and altered expression are also reported in various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Nemaline myopathy 1 (NEM1) | Missense mutations in TPM3 disrupt actin-tropomyosin interaction, impairing sarcomere function | ClinVar, OMIM |
| Congenital fiber-type disproportion (CFTD) | Dominant-negative mutations reduce slow-twitch fiber proportion | ClinVar, OMIM |
| Cap myopathy (CAPM1) | Mutations cause abnormal cap-like structures at myofiber periphery | ClinVar, OMIM |
| Breast cancer | TPM3 overexpression or fusion (e.g., TPM3-ALK) promotes cell motility | COSMIC, NCBI |
| Lung cancer | TPM3-ALK fusion drives oncogenic signaling | COSMIC, NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 112.5 | High |
| Heart | 78.3 | High |
| Brain | 12.1 | Low |
| Liver | 5.4 | Low |
| Kidney | 8.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.2 | Cervical cancer cell line |
| A549 | 22.8 | Lung cancer cell line |
| MCF7 | 18.5 | Breast cancer cell line |
| HepG2 | 9.3 | Liver cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| p.Met9Arg | Missense | Rare | Associated with nemaline myopathy; disrupts actin binding |
| p.Glu41Lys | Missense | Rare | Associated with CFTD; alters tropomyosin stability |
| p.Arg168Cys | Missense | Rare | Associated with cap myopathy; impairs filament regulation |
| TPM3-ALK fusion | Gene fusion | Somatic | Oncogenic driver in lung and breast cancer |
Mutation functional classification
Loss of Function (LOF)
Rare nonsense or frameshift mutations leading to haploinsufficiency in muscle disorders.
Gain of Function (GOF)
TPM3-ALK fusions constitutively activate ALK kinase, promoting cell proliferation.
Dominant Negative (DN)
Missense mutations (e.g., p.Met9Arg) produce abnormal tropomyosin that interferes with wild-type function in muscle.
View complete mutation data：
Gene Ontology (GO)
| • GO:0003779 - actin binding | • GO:0006936 - muscle contraction |
| • GO:0005862 - muscle thin filament tropomyosin | • GO:0051015 - actin filament binding |
| • GO:0030049 - muscle filament sliding |
Pathways
• Muscle contraction (Reactome R-HSA-397014)
• Striated muscle contraction (Reactome R-HSA-390522)
• Regulation of actin cytoskeleton (KEGG hsa04810)
Protein Summary
Tropomyosin 3 is a 284-amino acid protein that forms coiled-coil dimers and binds along actin filaments in muscle and non-muscle cells. It stabilizes actin filaments and regulates myosin interaction. Multiple isoforms exist due to alternative splicing. Mutations in TPM3 cause congenital myopathies, and gene fusions (e.g., TPM3-ALK) are recurrent in cancer.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TPM3 Knockout HEK293 Cell Line | EDJ-KQ1710 | Human | 7170 | Details Get a Quote |
| TPM3 Knockout A-549 Cell Line | EDJ-KQ22865 | Human | 7170 | Details Get a Quote |
| TPM3 Knockout HCT 116 Cell Line | EDJ-KQ22866 | Human | 7170 | Details Get a Quote |
| TPM3 Knockout HeLa Cell Line | EDJ-KQ22867 | Human | 7170 | Details Get a Quote |
| TPM3 Knockout IPEC-J2 Cell Line | EDC07504 | Pig | 414388 | Details Get a Quote |
| TPM3 Knockout Vero Cell Line | EDC07597 | Monkey | 103223933 | Details Get a Quote |
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