ACTA1 (Actin Alpha 1, Skeletal Muscle)
Key sarcomeric actin isoform in skeletal muscle; mutations cause congenital myopathies.
Gene Information Card
| Symbol | ACTA1 |
|---|---|
| Full Name | actin alpha 1, skeletal muscle |
| Gene Type | protein coding |
| Chromosomal Location | 1q42.13 |
| NCBI Gene ID | 58 ncbi.nlm.nih.gov/gene/58 |
| Ensembl ID | ENSG00000143632 |
| UniProt ID | P68133 |
| OMIM ID | 102610 |
| HGNC ID | 129 |
| Aliases | ACTA, ASMA, CFTD, MPFD, NEM1, NEM2, NEM3, actin, alpha 1, skeletal muscle |
Description
The ACTA1 gene encodes skeletal muscle alpha-actin, a major component of the sarcomeric thin filament in adult skeletal muscle. This protein is essential for muscle contraction and force generation. Mutations in ACTA1 are a common cause of congenital myopathies, including nemaline myopathy, actin myopathy, and intranuclear rod myopathy. The gene is highly conserved and expressed predominantly in skeletal muscle.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Nemaline Myopathy 3 (NEM3) | Missense or nonsense mutations disrupt actin filament assembly, leading to nemaline rod formation. | ClinVar, OMIM |
| Actin Myopathy | Dominant-negative mutations impair actin polymerization, causing muscle weakness and fiber disorganization. | OMIM, NCBI |
| Intranuclear Rod Myopathy | Mutations cause aggregation of actin into intranuclear rods, disrupting nuclear function. | OMIM, ClinVar |
| Congenital Fiber-Type Disproportion (CFTD) | Some ACTA1 mutations lead to type 1 fiber predominance and hypotonia. | OMIM, NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal Muscle | 1567.2 | High |
| Heart | 12.3 | Low |
| Liver | 0.0 | Not detected |
| Brain | 0.0 | Not detected |
| Lung | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Skeletal Muscle Myotubes | High | Differentiated muscle cells |
| Fibroblasts | Low | Non-muscle cells show minimal expression |
| HeLa | 0.0 | No detectable expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| p.Met1Val | Missense | Rare | Loss of start codon; reduced protein expression |
| p.Asp286Gly | Missense | Common in NEM3 | Dominant-negative; disrupts actin polymerization |
| p.Arg183His | Missense | Recurrent | Alters actin monomer conformation; nemaline rods |
| p.Glu259Lys | Missense | Rare | Impaired filament stability; actin myopathy |
Mutation functional classification
Loss of Function (LOF)
Nonsense or frameshift mutations leading to haploinsufficiency; rare, often severe.
Gain of Function (GOF)
Not typically described; most mutations are dominant-negative.
Dominant Negative (DN)
Common mechanism; mutant actin incorporates into filaments and disrupts sarcomere integrity.
View complete mutation data：
Gene Ontology (GO)
| • GO:0005524 - ATP binding | • GO:0005200 - structural constituent of cytoskeleton |
| • GO:0003779 - actin binding | • GO:0030049 - muscle filament sliding |
| • GO:0006936 - muscle contraction | • GO:0005856 - cytoskeleton |
| • GO:0015629 - actin cytoskeleton |
Pathways
• Skeletal muscle contraction (Reactome: R-HSA-397014)
• Sarcomere organization (Reactome: R-HSA-5250913)
• Actin nucleation and polymerization (Reactome: R-HSA-5663213)
Protein Summary
Skeletal muscle alpha-actin (42 kDa) is a globular protein that polymerizes into filamentous actin (F-actin), forming the core of the thin filament in sarcomeres. It interacts with myosin, tropomyosin, and troponin to regulate muscle contraction. The protein is highly conserved across vertebrates. Mutations often cause dominant-negative effects, leading to congenital myopathies characterized by muscle weakness, hypotonia, and characteristic rod-like inclusions.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ACTA1 Knockout HEK293 Cell Line | EDJ-KQ3339 | Human | 58 | Details Get a Quote |
| ACTA1 Knockout HeLa Cell Line | EDJ-KQ52540 | Human | 58 | Details Get a Quote |
| ACTA1 Knockout A-549 Cell Line | EDJ-KQ61022 | Human | 58 | Details Get a Quote |
| ACTA1 Knockout HCT 116 Cell Line | EDJ-KQ69497 | Human | 58 | Details Get a Quote |
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