The vertebrate muscle Z-disc: sarcomere anchor for structure and signalling

J Muscle Res Cell Motil. 2009;30(5-6):171-85. doi: 10.1007/s10974-009-9189-6. Epub 2009 Oct 15.


The Z-disc, appearing as a fine dense line forming sarcomere boundaries in striated muscles, when studied in detail reveals crosslinked filament arrays that transmit tension and house myriads of proteins with diverse functions. At the Z-disc the barbed ends of the antiparallel actin filaments from adjoining sarcomeres interdigitate and are crosslinked primarily by layers of alpha-actinin. The Z-disc is therefore the site of polarity reversal of the actin filaments, as needed to interact with the bipolar myosin filaments in successive sarcomeres. The layers of alpha-actinin determine the Z-disc width: fast fibres have narrow (approximately 30-50 nm) Z-discs and slow and cardiac fibres have wide (approximately 100 nm) Z-discs. Comprehensive reviews on the roles of the numerous proteins located at the Z-disc in signalling and disease have been published; the aim here is different, namely to review the advances in structural aspects of the Z-disc.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Actin Cytoskeleton / physiology
  • Actin Cytoskeleton / ultrastructure
  • Actinin / physiology
  • Actinin / ultrastructure
  • Animals
  • Cell Membrane Structures / physiology
  • Cell Membrane Structures / ultrastructure
  • Humans
  • Muscle Contraction / physiology
  • Muscle Fibers, Skeletal / physiology*
  • Muscle Fibers, Skeletal / ultrastructure
  • Muscle Proteins / metabolism
  • Muscle, Skeletal / physiology*
  • Muscle, Skeletal / ultrastructure*
  • Sarcomeres / physiology*
  • Sarcomeres / ultrastructure
  • Signal Transduction / physiology


  • Muscle Proteins
  • Actinin