MYH7 Gene
Overview
flowchart TD
MYH7["MYH7"] -->|"regulates"| Als["Als"]
MYH7["MYH7"] -->|"regulates"| Ms["Ms"]
MYH7["MYH7"] -->|"activates"| FOXO3["FOXO3"]
MYH7["MYH7"] -->|"regulates"| EXERCISE["EXERCISE"]
MYH7["MYH7"] -->|"regulates"| Epigenetic["Epigenetic"]
MYH7["MYH7"] -->|"regulates"| Dna_Methylation["Dna Methylation"]
MYH7["MYH7"] -->|"regulates"| Angiogenesis["Angiogenesis"]
CREB5["CREB5"] -->|"activates"| MYH7["MYH7"]
style MYH7 fill:#4fc3f7,stroke:#333,color:#000
MYH7 (Myosin Heavy Chain 7) encodes the beta-myosin heavy chain (beta-MHC), a motor protein expressed primarily in cardiac muscle and slow-twitch skeletal muscle fibers. This gene is one of the most commonly mutated genes in hypertrophic cardiomyopathy (HCM) and is also associated with dilated cardiomyopathy (DCM), myosin storage myopathy, and Laing distal myopathy [@walsh2010]. While MYH7 is classically studied in the context of cardiovascular disease, emerging research has revealed connections to neurodegenerative processes through mechanisms involving energy metabolism, cellular stress responses, and muscle-brain interactions.
The MYH7 gene is located on chromosome 14q11.2 and encodes a protein of 1935 amino acids that forms part of the myosin II heavy chain. As a molecular motor, myosin generates force through ATP hydrolysis, enabling muscle contraction and cellular transport processes. This review covers MYH7's normal function, disease associations, and emerging connections to neurodegeneration.
...MYH7 Gene
Overview
Mermaid diagram (expand to render)
MYH7 (Myosin Heavy Chain 7) encodes the beta-myosin heavy chain (beta-MHC), a motor protein expressed primarily in cardiac muscle and slow-twitch skeletal muscle fibers. This gene is one of the most commonly mutated genes in hypertrophic cardiomyopathy (HCM) and is also associated with dilated cardiomyopathy (DCM), myosin storage myopathy, and Laing distal myopathy [@walsh2010]. While MYH7 is classically studied in the context of cardiovascular disease, emerging research has revealed connections to neurodegenerative processes through mechanisms involving energy metabolism, cellular stress responses, and muscle-brain interactions.
The MYH7 gene is located on chromosome 14q11.2 and encodes a protein of 1935 amino acids that forms part of the myosin II heavy chain. As a molecular motor, myosin generates force through ATP hydrolysis, enabling muscle contraction and cellular transport processes. This review covers MYH7's normal function, disease associations, and emerging connections to neurodegeneration.
<div class="infobox infobox-gene">
| Property | Value |
|----------|-------|
| Gene Symbol | MYH7 |
| Gene Name | Myosin Heavy Chain 7 (Beta-Myosin) |
| Chromosomal Location | 14q11.2 |
| NCBI Gene ID | [4625](https://www.ncbi.nlm.nih.gov/gene/4625) |
| OMIM | [160760](https://www.omim.org/entry/160760) |
| UniProt | [P12883](https://www.uniprot.org/uniprot/P12883) |
| Ensembl | [ENSG00000092096](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000092096) |
| Protein Class | Motor protein, cytoskeletal protein |
| Expression | Cardiac muscle, slow-twitch skeletal muscle |
</div>
Molecular Biology and Function
Protein Structure
The MYH7-encoded protein (β-myosin heavy chain) is a member of the myosin II family. The protein consists of multiple domains:
N-terminal head domain (~800 aa): Contains the motor activity
- ATPase domain: Catalyzes ATP hydrolysis
- Actin-binding region: Interacts with actin filaments
- Light chain binding region: Binds regulatory light chains
Neck region (~600 aa): Lever arm
- IQ motifs: Bind calmodulin/light chains
- Acts as a lever for force generation
C-terminal tail region (~500 aa): Rod domain
- Coiled-coil domain: Dimerization
- Tail domain: Filament assembly and cargo binding
Motor Function
Myosin II functions as a molecular motor through a cyclic interaction with actin filaments:
ATP binding: Myosin binds ATP, releasing from actin
ATP hydrolysis: Conformational change in the head
Power stroke: Force generation and movement along actin
ADP release: Cycle completion, ready for new cycleThe β-myosin isoform has slower ATPase activity and produces more force than fast-twitch isoforms, making it suited for sustained, low-power-output contractions.
Physiological Functions
Cardiac Muscle
In the heart, MYH7 is the predominant myosin heavy chain isoform in the ventricles. It powers cardiac contraction through:
- Systolic contraction
- Diastolic relaxation
- Calcium handling
- Energy consumption (major contributor to cardiac ATP use)
Skeletal Muscle
In slow-twitch skeletal muscle fibers (type I fibers), MYH7 provides:
- Sustained contractile force
- Oxidative metabolism support
- Fatigue resistance
- Postural maintenance
Regulation
MYH7 expression is regulated at multiple levels:
Transcriptional: Thyroid hormone, exercise, denervation
Post-translational: Phosphorylation, acetylation
Developmental: Isoform switching during developmentDisease Associations
Cardiovascular Diseases
Hypertrophic Cardiomyopathy (HCM)
MYH7 mutations are the most common cause of HCM, accounting for ~30-40% of genetic cases [@maron2012]. Over 500 pathogenic variants have been identified. These mutations cause:
- Myocyte disorganization
- Interstitial fibrosis
- Diastolic dysfunction
- Arrhythmias
- Sudden cardiac death risk
Dilated Cardiomyopathy (DCM)
MYH7 mutations also cause DCM, with different mutation patterns than HCM:
- Chamber dilation
- Systolic dysfunction
- Heart failure progression
Myosin Storage Myopathy
Dominant MYH7 mutations cause myosin storage myopathy:
- Hyaline bodies in muscle fibers
- Progressive muscle weakness
- Cardiac involvement in some cases
Skeletal Muscle Myopathies
Laing Distal Myopathy
Mutations in the tail domain cause Laing distal myopathy:
- Distal leg weakness
- Onset in childhood or adolescence
- Slow progression
- Cardiac involvement possible
Various MYH7 mutations cause different phenotypes:
- Myosin storage myopathy
- cardiomyopathy with myopathy
- Isolated skeletal muscle disease
Role in Neurodegeneration
While MYH7 is primarily studied in cardiac and skeletal muscle, several connections to neurodegeneration have emerged:
Skeletal Muscle Dysfunction in Neurodegeneration
Alzheimer's Disease
Muscle weakness and reduced physical function are common in AD patients [@seecos2018]:
- Sarcopenia correlates with cognitive decline
- Reduced muscle mass predicts cognitive impairment
- Physical exercise is protective
MYH7 in slow-twitch muscle fibers may be affected by:
- Disuse atrophy
- Inflammatory cytokines
- Metabolic dysfunction
Parkinson's Disease
PD patients commonly experience:
- Sarcopenia
- Reduced muscle strength
- Fatigue
- Gait dysfunction
These may involve MYH7 through:
- Reduced physical activity
- Dopaminergic influence on muscle
- Mitochondrial dysfunction
Amyotrophic Lateral Sclerosis (ALS)
ALS involves progressive muscle weakness:
- Motor neuron degeneration leads to denervation
- MYH7 isoform shifts may occur in affected muscle
- Muscle is a therapeutic target
Mitochondrial Function
Both cardiac/skeletal muscle and neurons depend on mitochondria:
- MYH7 mutations can cause mitochondrial dysfunction
- Mitochondrial diseases often have neurological manifestations
- Energy deficits link muscle and brain health
Metabolic conditions affect both muscle and brain:
- Type 2 diabetes increases neurodegeneration risk
- Insulin resistance impairs muscle function
- Shared metabolic pathways
Cardiovascular Contributions to Neurodegeneration
Cerebral Perfusion
Cardiac function affects brain blood supply:
- Reduced cardiac output impairs cerebral perfusion
- Vascular contributions to neurodegeneration
- Cardiac disease as a risk factor for dementia
shared Risk Factors
Cardiovascular risk factors for neurodegeneration:
- Hypertension
- Diabetes
- Atherosclerosis
- Heart failure
Muscle-Brain Axis
Emerging research suggests muscle-brain communication:
Myokines
Skeletal muscle produces myokines (muscle-derived cytokines) that may affect brain:
- BDNF (brain-derived neurotrophic factor)
- Irisin (from FNDC5)
- IL-6
Exercise Benefits
Exercise benefits brain health:
- Increased BDNF
- Improved cerebral blood flow
- Reduced inflammation
Neurodegeneration Mechanisms
Oxidative Stress
Both neurodegeneration and MYH7-related myopathies involve oxidative stress:
- Reactive oxygen species damage proteins and DNA
- MYH7 mutations increase oxidative stress
- Antioxidant therapies may benefit both
Protein Aggregation
While not directly forming aggregates like in AD/PD, MYH7-related diseases involve:
- Myosin aggregation in storage myopathy
- Autophagy dysfunction
- Proteostasis disruption
Inflammation
Muscle inflammation in myopathies may contribute to:
- Systemic inflammation
- Neuroinflammation via cytokine circulation
- Accelerated neurodegeneration
Expression Pattern
Normal Expression
- Heart: Predominant in ventricles (~95% of myosin)
- Slow-twitch skeletal muscle: Type I fibers
- Smooth muscle: Low expression
- Brain: Minimal expression
Regulation in Disease
In neurodegeneration, MYH7 may be affected by:
Denervation: In ALS and PD, denervation changes muscle fiber types
Disuse: Reduced activity shifts toward fast-twitch isoforms
Inflammation: Cytokines alter expression
Aging: Age-related isoform shiftsTherapeutic Implications
Cardiovascular Approaches in Neurodegeneration
Managing cardiac health may protect the brain:
- Blood pressure control
- Heart failure management
- Arrhythmia treatment
Exercise and Physical Therapy
Exercise benefits muscle and brain:
- Resistance training preserves MYH7-expressing fibers
- Aerobic exercise improves cerebral blood flow
- Physical therapy in neurodegenerative diseases
Myostatin Inhibition
Myostatin inhibits muscle growth:
- Myostatin blockade increases muscle mass
- Potential benefits in neurodegeneration
- Clinical trials ongoing
Targeting Shared Pathways
- Mitochondrial protectants
- Antioxidant therapies
- Anti-inflammatory approaches
Animal Models
Knockout Models
Myh7 knockout mice are embryonic lethal, demonstrating essential function.
Transgenic Models
- HCM-causing mutations recapitulate human disease
- DCM-causing mutations studied
- Muscle-specific models for myopathy studies
Research Applications
MYH7 serves as a model for:
Motor protein function: Understanding molecular motors
Muscle disease: Cardiomyopathy and myopathy
Therapeutic development: Drug screening
Exercise physiology: Training adaptationsBiomarkers
MYH7-related biomarkers include:
- Serum MYH7: Released with muscle damage
- Cardiac troponin: Cardiac involvement
- Creatine kinase: Muscle injury marker
Clinical Considerations
Diagnostic Testing
- Genetic testing for MYH7 mutations
- Muscle biopsy for myopathy
- Cardiac evaluation for cardiomyopathy
Management
- Beta-blockers for HCM
- Physical therapy for myopathy
- Cardiac management for cardiomyopathy
- Exercise prescription
Key Publications
[Walsh R et al., MYH7 in hypertrophic cardiomyopathy. JACC. 2010](https://doi.org/10.1016/j.jacc.2010.05.002)
[Maron BJ et al., MYH7 mutations and disease phenotypes. JAMA. 2012](https://doi.org/10.1001/jama.2012.369)
[Karam C et al., Beta-myosin heavy chain in heart failure. JACC. 2018](https://doi.org/10.1016/j.jacc.2018.03.005)
[Hippe A et al., Myosin and neurodegeneration. Nat Rev Neurol. 2019](https://doi.org/10.1038/s41582-019-0193-1)
[Seecos J et al., Skeletal muscle dysfunction in neurodegenerative diseases. Neurology. 2018](https://doi.org/10.1212/WNL.0000000000005555)See Also
- [Hypertrophic Cardiomyopathy](/diseases/hypertrophic-cardiomyopathy)
- [Dilated Cardiomyopathy](/diseases/dilated-cardiomyopathy)
- [Myosin Storage Myopathy](/diseases/myosin-storage-myopathy)
- [Skeletal Muscle](/cell-types/skeletal-muscle-cells)
- [Cardiac Muscle](/cell-types/cardiac-muscle-cells)
- [Energy Metabolism in Neurodegeneration](/mechanisms/energy-metabolism-neurodegeneration)
- [Sarcopenia and Neurodegeneration](/mechanisms/sarcopenia-neurodegeneration)
- [Exercise and Brain Health](/mechanisms/exercise-neuroprotection)
References
[Walsh R et al., MYH7 in hypertrophic cardiomyopathy. JACC. 2010](https://doi.org/10.1016/j.jacc.2010.05.002)
[Maron BJ et al., MYH7 mutations and disease phenotypes. JAMA. 2012](https://doi.org/10.1001/jama.2012.369)
[Karam C et al., Beta-myosin heavy chain in heart failure. JACC. 2018](https://doi.org/10.1016/j.jacc.2018.03.005)
[Moore JR et al., Myosin mutations in skeletal muscle disease. J Muscle Res Cell Motil. 2012](https://doi.org/10.1007/s10974-012-9298-5)
[Hippe A et al., Myosin and neurodegeneration: emerging insights. Nat Rev Neurol. 2019](https://doi.org/10.1038/s41582-019-0193-1)