Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Palindromic assembly of the giant muscle protein titin in the sarcomeric Z-disk


The Z-disk of striated and cardiac muscle sarcomeres is one of the most densely packed cellular structures in eukaryotic cells1. It provides the architectural framework for assembling and anchoring the largest known muscle filament systems by an extensive network of protein–protein interactions, requiring an extraordinary level of mechanical stability. Here we show, using X-ray crystallography, how the amino terminus of the longest filament component, the giant muscle protein titin, is assembled into an antiparallel (2:1) sandwich complex by the Z-disk ligand telethonin. The pseudosymmetric structure of telethonin mediates a unique palindromic arrangement of two titin filaments, a type of molecular assembly previously found only in protein–DNA complexes. We have confirmed its unique architecture in vivo by protein complementation assays, and in vitro by experiments using fluorescence resonance energy transfer. The model proposed may provide a molecular paradigm of how major sarcomeric filaments are crosslinked, anchored and aligned within complex cytoskeletal networks.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

Figure 1: Structure of the palindromic titin–telethonin–titin complex.
Figure 2: Telethonin-mediated assembly and Z-disk anchoring of titin filaments.
Figure 3: Evidence for the formation of the palindromic titin–telethonin complex in vivo and in vitro.
Figure 4: Model outlining the involvement of the titin–telethonin complex in the architecture of the sarcomeric Z-disk.


  1. Clark, K. A., McElhinny, A. S., Beckerle, M. C. & Gregorio, C. C. Striated muscle cytoarchitecture: an intricate web of form and function. Annu. Rev. Cell Dev. Biol. 18, 637–706 (2002)

    Article  CAS  Google Scholar 

  2. Tskhovrebova, L. & Trinick, J. Titin: properties and family relationships. Nature Rev. Mol. Cell Biol. 4, 679–689 (2003)

    Article  CAS  Google Scholar 

  3. Gregorio, C. C. et al. The NH2 terminus of titin spans the Z-disc: its interaction with a novel 19-kD ligand (T-cap) is required for sarcomeric integrity. J. Cell Biol. 143, 1013–1027 (1998)

    Article  CAS  Google Scholar 

  4. Mues, A., van der Ven, P. F., Young, P., Furst, D. O. & Gautel, M. Two immunoglobulin-like domains of the Z-disc portion of titin interact in a conformation-dependent way with telethonin. FEBS Lett. 428, 111–114 (1998)

    Article  CAS  Google Scholar 

  5. Sorimachi, H. et al. Tissue-specific expression and α-actinin binding properties of the Z-disc titin: implications for the nature of vertebrate Z-discs. J. Mol. Biol. 270, 688–695 (1997)

    Article  CAS  Google Scholar 

  6. Young, P., Ferguson, C., Banuelos, S. & Gautel, M. Molecular structure of the sarcomeric Z-disk: two types of titin interactions lead to an asymmetrical sorting of α-actinin. EMBO J. 17, 1614–1624 (1998)

    Article  CAS  Google Scholar 

  7. Wang, J. et al. Dynamics of Z-band based proteins in developing skeletal muscle cells. Cell Motil. Cytoskel. 61, 34–48 (2005)

    Article  CAS  Google Scholar 

  8. Pyle, W. G. & Solaro, R. J. At the crossroads of myocardial signaling: the role of Z-discs in intracellular signaling and cardiac function. Circ. Res. 94, 296–305 (2004)

    Article  CAS  Google Scholar 

  9. Labeit, S. & Kolmerer, B. Titins: giant proteins in charge of muscle ultrastructure and elasticity. Science 270, 293–296 (1995)

    Article  CAS  ADS  Google Scholar 

  10. Knoll, R. et al. The cardiac mechanical stretch sensor machinery involves a Z disc complex that is defective in a subset of human dilated cardiomyopathy. Cell 111, 943–955 (2002)

    Article  CAS  Google Scholar 

  11. Moreira, E. S. et al. Limb-girdle muscular dystrophy type 2G is caused by mutations in the gene encoding the sarcomeric protein telethonin. Nature Genet. 24, 163–166 (2000)

    Article  CAS  Google Scholar 

  12. Hayashi, T. et al. Tcap gene mutations in hypertrophic cardiomyopathy and dilated cardiomyopathy. J. Am. Coll. Cardiol. 44, 2192–2201 (2004)

    Article  CAS  Google Scholar 

  13. Guddat, L. W. et al. Intramolecular signaling upon complexation. FASEB J. 9, 101–106 (1995)

    Article  CAS  Google Scholar 

  14. Ramsland, P. A. & Farrugia, W. Crystal structures of human antibodies: a detailed and unfinished tapestry of immunoglobulin gene products. J. Mol. Recognit. 15, 248–259 (2002)

    Article  CAS  Google Scholar 

  15. Remenyi, A., Scholer, H. R. & Wilmanns, M. Combinatorial control of gene expression. Nature Struct. Mol. Biol. 11, 812–815 (2004)

    Article  CAS  Google Scholar 

  16. Fang, D. & Kerppola, T. K. Ubiquitin-mediated fluorescence complementation reveals that Jun ubiquitinated by Itch/AIP4 is localized to lysosomes. Proc. Natl Acad. Sci. USA 101, 14782–14787 (2004)

    Article  CAS  ADS  Google Scholar 

  17. Liversage, A. D., Holmes, D., Knight, P. J., Tskhovrebova, L. & Trinick, J. Titin and the sarcomere symmetry paradox. J. Mol. Biol. 305, 401–409 (2001)

    Article  CAS  Google Scholar 

  18. Luther, P. K. & Squire, J. M. Muscle Z-band ultrastructure: titin Z-repeats and Z-band periodicities do not match. J. Mol. Biol. 319, 1157–1164 (2002)

    Article  CAS  Google Scholar 

  19. Atkinson, R. A. et al. Ca2+-independent binding of an EF-hand domain to a novel motif in the α–actinin–titin complex. Nature Struct. Biol. 8, 853–857 (2001)

    Article  CAS  Google Scholar 

  20. Furst, D. O., Osborn, M., Nave, R. & Weber, K. The organization of titin filaments in the half-sarcomere revealed by monoclonal antibodies in immunoelectron microscopy: a map of ten nonrepetitive epitopes starting at the Z line extends close to the M line. J. Cell Biol. 106, 1563–1572 (1988)

    Article  CAS  Google Scholar 

  21. Schroder, R. et al. Early and selective disappearance of telethonin protein from the sarcomere in neurogenic atrophy. J. Muscle Res. Cell Motil. 22, 259–264 (2001)

    Article  CAS  ADS  Google Scholar 

  22. Kontrogianni-Konstantopoulos, A. & Bloch, R. J. The hydrophilic domain of small ankyrin-1 interacts with the two N-terminal immunoglobulin domains of titin. J. Biol. Chem. 278, 3985–3991 (2003)

    Article  CAS  Google Scholar 

  23. Faulkner, G., Lanfranchi, G. & Valle, G. Telethonin and other new proteins of the Z-disc of skeletal muscle. IUBMB Life 51, 275–282 (2001)

    Article  CAS  Google Scholar 

  24. Frey, N. & Olson, E. N. Calsarcin-3, a novel skeletal muscle-specific member of the calsarcin family, interacts with multiple Z-disc proteins. J. Biol. Chem. 277, 13998–14004 (2002)

    Article  CAS  Google Scholar 

  25. Furukawa, T. et al. Specific interaction of the potassium channel β-subunit minK with the sarcomeric protein T-cap suggests a T-tubule-myofibril linking system. J. Mol. Biol. 313, 775–784 (2001)

    Article  CAS  Google Scholar 

  26. Mayans, O. et al. Structural basis for activation of the titin kinase domain during myofibrillogenesis. Nature 395, 863–869 (1998)

    Article  CAS  ADS  Google Scholar 

  27. Djinovic-Carugo, K., Young, P., Gautel, M. & Saraste, M. Structure of the α-actinin rod: molecular basis for cross-linking of actin filaments. Cell 98, 537–546 (1999)

    Article  CAS  Google Scholar 

  28. Li, H. et al. Reverse engineering of the giant muscle protein titin. Nature 418, 998–1002 (2002)

    Article  CAS  ADS  Google Scholar 

  29. Zou, P. et al. Solution scattering suggests cross-linking function of telethonin in the complex with titin. J. Biol. Chem. 278, 2636–2644 (2003)

    Article  CAS  Google Scholar 

  30. Auerbach, D. et al. Different domains of the M-band protein myomesin are involved in myosin binding and M-band targeting. Mol. Biol. Cell 10, 1297–1308 (1999)

    Article  CAS  Google Scholar 

Download references


We thank D. Fürst for the gift of antibodies; R. Kühnemuth for discussions on the FRET experiments; M. Forster for involvement in expression and purification tests; G. Burenkov for assistance during data collection at beamline BW6 at MPG-ASMB/DESY; E. Mandelkow and M. von Bergen for making the fluorimeter at MPG-ASMB/DESY available; and E. Ehler for the preparation of neonatal rat cardiomyocyte cultures. N.P. and S.L. were supported by the EU research and training network CAMKIN to M.W. and M.G., respectively. During involvement at the project, O.M. was supported by an EU Marie-Curie postdoctoral fellowship.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Matthias Wilmanns.

Ethics declarations

Competing interests

Coordinates and structure factors have been deposited in the Protein Data Bank under accession number 1YA5. Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Discussion

Summarization of previous data on structural assemblies of immunoglobulin (IG)-like domain containing proteins. (PDF 88 kb)

Supplementary Methods

Details on production of seleno-L-methionine (SeMet)–incorporated telethonin, cellular targeting of telethonin and its mutants, antibodies, confocal microscopy. (PDF 125 kb)

Supplementary Table 1

In vitro/in vivo titin-telethonin assembly and localisation data of four telethonin mutants are listed. (PDF 75 kb)

Supplementary Table 2

X-ray data collection and phasing statistics of the structure of the titin/telethonin complex are summarised. (PDF 147 kb)

Supplementary Figure 1

The structure of the (2:1) titin/telethonin complex is shown schematically. (PDF 59 kb)

Supplementary Figure 2

Confocal images of neonatal rat cardiomyocytes that were transiently transfected with six different variants of telethonin. Those variants in which the structure of one the two telethonin β -hairpins was affected do not properly localise to the Z-disk. (PDF 7255 kb)

Supplementary Figure 3

Titin/telethonin complex formation of several telethonin variants under in vitro conditions, as evidenced by native gel electrophoresis. Those variants in which the structure of one the two telethonin β -hairpins was affected do allow complex formation. (PDF 3304 kb)

Supplementary Figure 4

Titin/telethonin complex formation of several telethonin variants in COS cells using a YFP-complementation assay. Those variants in which the structure of one the two telethonin β -hairpins was affected do not complement. (PDF 1977 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Zou, P., Pinotsis, N., Lange, S. et al. Palindromic assembly of the giant muscle protein titin in the sarcomeric Z-disk. Nature 439, 229–233 (2006).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing