A two-segment model for thin filament architecture in skeletal muscle

Nat Rev Mol Cell Biol. 2013 Feb;14(2):113-9. doi: 10.1038/nrm3510. Epub 2013 Jan 9.

Abstract

Correct specification of myofilament length is essential for efficient skeletal muscle contraction. The length of thin actin filaments can be explained by a novel 'two-segment' model, wherein the thin filaments consist of two concatenated segments, which are of either constant or variable length. This is in contrast to the classic 'nebulin ruler' model, which postulates that thin filaments are uniform structures, the lengths of which are dictated by nebulin. The two-segment model implicates position-specific microregulation of actin dynamics as a general principle underlying actin filament length and stability.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / chemistry*
  • Actin Cytoskeleton / physiology*
  • Animals
  • CapZ Actin Capping Protein / metabolism
  • CapZ Actin Capping Protein / physiology
  • Humans
  • Models, Biological*
  • Muscle Contraction / physiology
  • Muscle Proteins / metabolism
  • Muscle Proteins / physiology
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / physiology
  • Muscle, Skeletal / ultrastructure*
  • Myofibrils / chemistry
  • Myofibrils / metabolism
  • Myofibrils / physiology
  • Myofibrils / ultrastructure
  • Myopathies, Nemaline / genetics
  • Myopathies, Nemaline / metabolism
  • Myopathies, Nemaline / pathology
  • Myopathies, Nemaline / physiopathology
  • Sarcomeres / metabolism
  • Sarcomeres / physiology
  • Tropomyosin / metabolism
  • Tropomyosin / physiology

Substances

  • CapZ Actin Capping Protein
  • Muscle Proteins
  • Tropomyosin
  • nebulin