MYH1 Gene - Myosin Heavy Chain 1: Function, Mutations, and Associated Diseases

MYH1 encodes the myosin heavy chain 1 (MyHC-2x), a major contractile protein in adult fast-twitch type IIx skeletal muscle fibers. It forms the thick filament of the sarcomere and generates the force for muscle contraction through ATP hydrolysis. MYH1 is part of the myosin heavy chain gene cluster on chromosome 17p13.1, which includes MYH2, MYH3, and MYH4. Mutations in MYH1 are associated with autosomal dominant myopathies, including myosin storage myopathy and congenital fiber-type disproportion.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• R-HSA-397014 - Muscle contraction

• R-HSA-445355 - Smooth muscle contraction

• R-HSA-390522 - Striated muscle contraction

• WP:WP383 - Myogenesis pathway

MYH1 encodes the myosin heavy chain 1 (MyHC-2x), a 1939-amino-acid protein that forms the core of the thick filament in fast-twitch type IIx skeletal muscle fibers. The protein contains an N-terminal globular head domain (motor domain) that binds actin and hydrolyzes ATP, a neck region with light chain binding sites, and a long coiled-coil rod domain responsible for filament assembly. MYH1 is essential for rapid, powerful muscle contractions. Mutations in MYH1 cause autosomal dominant myopathies, including myosin storage myopathy and congenital fiber-type disproportion, by disrupting sarcomere integrity or contractile kinetics.