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

• Published in: Journal of muscle research and cell motility Vol. 30; no. 5-6; pp. 171 - 185
• Main Author: Luther, Pradeep K
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 2009; Springer Netherlands; Springer Nature B.V
• Subjects: actin; Actin Cytoskeleton - physiology; Actin Cytoskeleton - ultrastructure; Actinin - physiology; Actinin - ultrastructure; Alpha-actinin; Animal Anatomy; Animals; Biomedical and Life Sciences; Biomedicine; Cell Biology; Cell Membrane Structures - physiology; Cell Membrane Structures - ultrastructure; electron microscopy; Histology; Humans; Life Sciences; Morphology; Muscle Contraction - physiology; Muscle Fibers, Skeletal - physiology; Muscle Fibers, Skeletal - ultrastructure; Muscle proteins; Muscle Proteins - metabolism; Muscle, Skeletal - physiology; Muscle, Skeletal - ultrastructure; Proteomics; Review Paper; Sarcomeres - physiology; Sarcomeres - ultrastructure; Signal Transduction - physiology; Z-band; Z-line; Alpha-actinin; Z-band; Muscle proteins; Electron microscopy; Actin; Z-line
• ISSN: 0142-4319; 1573-2657
• DOI: 10.1007/s10974-009-9189-6

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 α-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 α-actinin determine the Z-disc width: fast fibres have narrow (~30-50 nm) Z-discs and slow and cardiac fibres have wide (~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.