MYL1: Myosin Light Chain 1 - A Key Sarcomeric Protein in Skeletal Muscle
Comprehensive gene overview of MYL1, encoding the essential myosin light chain 1 (MLC1f) in fast-twitch skeletal muscle, with clinical relevance to myopathies and muscle function.
Gene Information Card
| Symbol | MYL1 |
|---|---|
| Full Name | Myosin Light Chain 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 2q34 |
| NCBI Gene ID | 4632 ncbi.nlm.nih.gov/gene/4632 |
| Ensembl ID | ENSG00000168542 |
| UniProt ID | P05976 |
| OMIM ID | 160780 |
| HGNC ID | 7582 |
| Aliases | MLC1F, MLC1, MLC-1f, MYL1A |
Description
MYL1 (myosin light chain 1) encodes the fast skeletal muscle myosin alkali light chain (MLC1f), a component of the hexameric myosin complex. This protein binds calcium and modulates actin-activated ATPase activity, playing a critical role in muscle contraction velocity and force generation in fast-twitch (type II) fibers. Mutations in MYL1 are associated with myopathy and muscle weakness.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Myopathy, myosin storage, autosomal recessive | Loss-of-function mutations in MYL1 lead to accumulation of myosin heavy chain and muscle fiber atrophy, causing progressive muscle weakness. | ClinVar, OMIM #160780 |
| Nemaline myopathy 8 | Missense variants in MYL1 disrupt sarcomere assembly, resulting in nemaline rods and congenital myopathy. | ClinVar, OMIM #617336 |
| Distal myopathy | Rare MYL1 variants associated with distal muscle weakness and wasting, likely due to impaired myosin light chain function. | ClinVar, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle (fast-twitch) | 1200.5 | High |
| Heart | 15.2 | Low |
| Esophagus | 8.1 | Low |
| Tongue | 6.3 | Low |
| Other tissues | <1.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| LHCN-M2 (human skeletal muscle myoblasts) | 850.0 | Differentiated myotubes show high expression |
| RD (rhabdomyosarcoma) | 320.0 | Moderate expression |
| HeLa | 0.5 | Not expressed |
| HEK293 | 0.2 | Not expressed |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.64G>A (p.Glu22Lys) | Missense | Rare | Alters calcium binding affinity; associated with nemaline myopathy |
| c.172C>T (p.Arg58Trp) | Missense | Rare | Disrupts actin binding; causes myosin storage myopathy |
| c.433_434del (p.Lys145Glufs*3) | Frameshift | Very rare | Loss of function; leads to protein truncation and myopathy |
| c.485A>G (p.Asn162Ser) | Missense | Rare | Reduced ATPase activity; distal myopathy phenotype |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations (e.g., p.Lys145Glufs*3) cause premature termination and loss of MLC1f protein, leading to myosin storage myopathy.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported for MYL1.
Dominant Negative (DN)
Missense variants (e.g., p.Glu22Lys) may exert dominant-negative effects by incorporating mutant light chain into the myosin complex, impairing sarcomere function.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Smooth Muscle Contraction (Reactome: R-HSA-445355)
• Muscle contraction (KEGG: hsa04260)
• Cardiac muscle contraction (KEGG: hsa04260) - indirect via myosin light chain
Protein Summary
Myosin light chain 1 (MLC1f) is a 194-amino acid protein (22 kDa) belonging to the EF-hand superfamily. It contains three EF-hand motifs that bind calcium, regulating the lever-arm movement of myosin heads during contraction. MLC1f is exclusively expressed in fast-twitch skeletal muscle fibers and is essential for high-velocity contractions. Post-translational modifications include phosphorylation at Ser15, which modulates myosin ATPase activity.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MYL1 Knockout HEK293 Cell Line | EDJ-KQ5285 | Human | 4632 | Details Get a Quote |
| MYL12B Knockout HEK293 Cell Line | EDJ-KQ5466 | Human | 103910 | Details Get a Quote |
| MYL12A Knockout HEK293 Cell Line | EDJ-KQ7114 | Human | 10627 | Details Get a Quote |
| MYL10 Knockout HEK293 Cell Line | EDJ-KQ11230 | Human | 93408 | Details Get a Quote |
| MYL11 Knockout HEK293 Cell Line | EDJ-KQ14341 | Human | 29895 | Details Get a Quote |
| MYL12A Knockout A-549 Cell Line | EDJ-KQ31983 | Human | 10627 | Details Get a Quote |
| MYL12A Knockout HeLa Cell Line | EDJ-KQ31985 | Human | 10627 | Details Get a Quote |
| MYL11 Knockout HeLa Cell Line | EDJ-KQ44455 | Human | 29895 | Details Get a Quote |
| MYL12B Knockout A-549 Cell Line | EDJ-KQ28666 | Human | 103910 | Details Get a Quote |
| MYL12B Knockout HCT 116 Cell Line | EDJ-KQ28667 | Human | 103910 | Details Get a Quote |
| MYL12B Knockout HeLa Cell Line | EDJ-KQ28668 | Human | 103910 | Details Get a Quote |
| MYL12A Knockout HCT 116 Cell Line | EDJ-KQ30604 | Human | 10627 | Details Get a Quote |
| Myl12a Knockout RAW 264.7 Cell Line | EDJ-KZ355 | Mouse | 67268 | Details Get a Quote |
| MYL1 Knockout HeLa Cell Line | EDJ-KQ53945 | Human | 4632 | Details Get a Quote |
| MYL10 Knockout HeLa Cell Line | EDJ-KQ57862 | Human | 93408 | Details Get a Quote |
Displaying Records 1 To 15 Of 21 Records
