Myosin heavy chain skeletal muscle embryonic (MyHC-embryonic (MyHC-emb))

The myosin heavy chain skeletal muscle embryonic, also known as MyHC-embryonic or MYH3, is a skeletal muscle-specific contractile protein expressed primarily during early embryonic muscle development. It functions as a molecular motor within the sarcomere thick filaments, converting ATP hydrolysis into mechanical force for muscle contraction via interactions with actin filaments in the cross-bridge cycle. This isoform is crucial for myogenesis, regulating both cell-autonomous processes in muscle differentiation and non-cell-autonomous effects on myogenic progenitors and myoblasts through the fibroblast growth factor (FGF) signaling pathway. Mutations in the MYH3 gene cause distal arthrogryposis syndromes, including Freeman-Sheldon and Sheldon-Hall syndromes, characterized by congenital contractures, scoliosis, and muscle fiber alterations. In knockout models, loss of MyHC-embryonic leads to reduced muscle fiber size and number, disrupted progenitor pools, and postnatal skeletal defects. As a developmental isoform, its expression diminishes postnatally, replaced by adult myosin heavy chain isoforms, highlighting its specialized role in transient embryonic muscle function rather than mature physiology. No approved drugs directly target this protein, reflecting its limited therapeutic relevance outside rare genetic disorders.

Other names

Myosin heavy chain-embryonicMyHC-embryonicMYH3