myosin heavy chain 7; myosin-7; myosin heavy chain beta, cardiac muscle isoform; MyHC-beta; myosin heavy chain slow isoform; MyHC-slow (MYH7, MYHCB)

Function

• muscle contraction
• myosin heavy chain

Structure

• muscle myosin is a hexameric protein that consists of
  • 2 myosin heavy chain subunits
  • 2 myosin essential light chain subunits
  • 2 myosin regulatory light chain subunits
• each myosin heavy chain can be split into 1 light meromyosin & 1 heavy meromyosin; it can later be split further into 2 globular subfragments (S1) & 1 rod-shaped subfragment (S2)
• rodlike tail sequence is highly repetitive, showing cycles of a 28-residue repeat pattern composed of 4 heptapeptides, characteristic for alpha-helical coiled coils
• contains 1 IQ domain
• contains 1 myosin head-like domain

Compartment

• cytoplasm, myofibril
• thick filaments of the myofibrils

Expression

found in cardiac muscle

Pathology

• defects in MYH7 are the cause of
  • familial hypertrophic cardiomyopathy type 1
  • myosin storage myopathy
  • scapuloperoneal myopathy
  • cardiomyopathy dilated type 1S
  • Laing early-onset distal myopathy
  • restrictive cardiomyopathy

Notes

• the cardiac alpha isoform is a 'fast' ATPase myosin, while the beta isoform is a 'slow' ATPase; MYH7 is a beta isoform

More general terms

• myosin heavy chain

Additional terms

• myosin

Database

• UniProt: http://www.uniprot.org/uniprot/P12883.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4625
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4625
• OMIM: https://mirror.omim.org/entry/160500
• OMIM: https://mirror.omim.org/entry/160760
• OMIM: https://mirror.omim.org/entry/181430
• OMIM: https://mirror.omim.org/entry/192600
• OMIM: https://mirror.omim.org/entry/608358