Differential splicing of the large sarcomeric protein nebulin during skeletal muscle development

J Struct Biol. 2010 May;170(2):325-33. doi: 10.1016/j.jsb.2010.02.014. Epub 2010 Feb 20.


We studied differential splicing of nebulin, a giant filamentous F-actin binding protein (M(r) approximately 700-800kDa) that is found in skeletal muscle. Nebulin spans the thin filament length, its C-terminus is anchored in the Z-disc, and its N-terminal region is located toward the thin filament pointed end. Various lines of evidence indicate that nebulin plays important roles in thin filament and Z-disc structure in skeletal muscle. In the present work we studied nebulin in a range of muscle types during postnatal development and performed transcript studies with a mouse nebulin exon microarray, developed by us, whose results were confirmed by RT-PCR. We also performed protein studies with high-resolution SDS-agarose gels and Western blots, and structural studies with electron microscopy. We found during postnatal development of the soleus muscle major changes in splicing in both the super-repeat region and the Z-disc region of nebulin; interestingly, these changes were absent in other muscle types. Three novel Z-disc exons, previously described in the mouse gene, were upregulated during postnatal development of soleus muscle and this was correlated with a significant increase in Z-disc width. These findings support the view that nebulin plays an important role in Z-disc width regulation. In summary, we discovered changes in both the super-repeat region and the Z-disc region of nebulin, that these changes are muscle-type specific, and that they correlate with differences in sarcomere structure.

Publication types

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

MeSH terms

  • Alternative Splicing*
  • Animals
  • Exons
  • Mice
  • Microarray Analysis
  • Microscopy, Electron
  • Muscle Proteins / genetics
  • Muscle Proteins / metabolism*
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / growth & development*
  • Muscle, Skeletal / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction / methods


  • Muscle Proteins
  • nebulin