The nebulin SH3 domain is dispensable for normal skeletal muscle structure but is required for effective active load bearing in mouse

Daniel L. Yamamoto, Carmen Vitiello, Jianlin Zhang, David S. Gokhin, Alessandra Castaldi, Gerald Coulis, Fabio Piaser, Maria Carmela Filomena, Peter J. Eggenhuizen, Paolo Kunderfranco, Serena Camerini, Kazunori Takano, Takeshi Endo, Marco Crescenzi, Pradeep K L Luther, Richard L. Lieber, Ju Chen, Marie Louise Bang

Research output: Contribution to journalArticlepeer-review

Abstract

Nemaline myopathy (NM) is a congenital myopathy with an estimated incidence of 1:50,000 live births. It is caused by mutations in thin filament components, including nebulin, which accounts for about 50% of the cases. The identification of NM cases with nonsense mutations resulting in loss of the extreme C-terminal SH3 domain of nebulin suggests an important role of the nebulin SH3 domain, which is further supported by the recent demonstration of its role in IGF-1-induced sarcomeric actin filament formation through targeting of N-WASP to the Z-line. To provide further insights into the functional significance of the nebulin SH3 domain in the Z-disk and to understand the mechanisms by which truncations of nebulin lead to NM, we took two approaches: (1) an affinity-based proteomic screening to identify novel interaction partners of the nebulin SH3 domain; and (2) generation and characterization of a novel knockin mouse model with a premature stop codon in the nebulin gene, eliminating its C-terminal SH3 domain (NebδSH3 mouse). Surprisingly, detailed analyses of NebδSH3 mice revealed no structural or histological skeletal muscle abnormalities and no changes in gene expression or localization of interaction partners of the nebulin SH3 domain, including myopalladin, palladin, zyxin and N-WASP. Also, no significant effect on peak isometric stress production, passive tensile stress or Young's modulus was found. However, NebδSH3 muscle displayed a slightly altered force-frequency relationship and was significantly more susceptible to eccentric contraction-induced injury, suggesting that the nebulin SH3 domain protects against eccentric contraction-induced injury and possibly plays a role in finetuning the excitation-contraction coupling mechanism.

Original languageEnglish
Pages (from-to)5477-5489
Number of pages13
JournalJournal of Cell Science
Volume126
Issue number23
DOIs
Publication statusPublished - Dec 1 2013

Keywords

  • Nebulin
  • Nemaline myopathy
  • Sarcomere
  • Skeletal muscle
  • Z-line

ASJC Scopus subject areas

  • Cell Biology

Fingerprint

Dive into the research topics of 'The nebulin SH3 domain is dispensable for normal skeletal muscle structure but is required for effective active load bearing in mouse'. Together they form a unique fingerprint.

Cite this