Myosin-1, also known as 'striated muscle myosin heavy chain 1', is a protein that in humans is encoded by the MYH1gene.[5][6] This gene is most highly expressed in fast type IIX/D muscle fibres of vertebrates and encodes a protein found uniquely in striated muscle; it is a class II myosin with a long coiled coil tail that dimerizes and should not be confused with 'Myosin 1' encoded by the MYO1 family of genes (MYO1A-MYO1H). Class I MYO1 genes function in many cell types throughout biology and are single-headed membrane-binding myosins that lack a long coiled coil tail.
Myosin is a major contractile protein that converts chemical energy into mechanical energy through the hydrolysis of ATP. Class II Myosins are hexameric proteins composed of a pair of myosin heavy chains (MYH) and two pairs of nonidentical light chains. Myosin heavy chains are encoded by a multigene family. In mammals, at least ten different myosin heavy chain (MYH) isoforms have been described from striated, smooth, but rarely in non-muscle cells. These isoforms show expression that is spatially and temporally regulated during development.[6]
Smerdu V, Karsch-Mizrachi I, Campione M, Leinwand L, Schiaffino S (December 1994). "Type IIx myosin heavy chain transcripts are expressed in type IIb fibers of human skeletal muscle". The American Journal of Physiology. 267 (6 Pt 1): C1723–8. doi:10.1152/ajpcell.1994.267.6.C1723. PMID7545970.
Weiss A, Schiaffino S, Leinwand LA (July 1999). "Comparative sequence analysis of the complete human sarcomeric myosin heavy chain family: implications for functional diversity". Journal of Molecular Biology. 290 (1): 61–75. doi:10.1006/jmbi.1999.2865. PMID10388558.
Korfage JA, Brugman P, Van Eijden TM (September 2000). "Intermuscular and intramuscular differences in myosin heavy chain composition of the human masticatory muscles". Journal of the Neurological Sciences. 178 (2): 95–106. doi:10.1016/S0022-510X(00)00372-5. PMID11018701. S2CID24218883.
Pontén EM, Stål PS (February 2007). "Decreased capillarization and a shift to fast myosin heavy chain IIx in the biceps brachii muscle from young adults with spastic paresis". Journal of the Neurological Sciences. 253 (1–2): 25–33. doi:10.1016/j.jns.2006.11.006. PMID17196619. S2CID23299020.