Comparative proteomic analysis of myotube caveolae after milli-calpain deregulation

Proteomics. 2007 Sep;7(18):3289-98. doi: 10.1002/pmic.200700124.

Abstract

Caveolae are specialised RAFTs (detergent-resistant membrane microdomains enriched in cholesterol and glycosphingolipids). Caveolin, the main caveolae protein, is essential to the organisation of proteins and lipids, and interacts with numerous mediating proteins through a 'Caveolin Scalfolding Domain'. Consequently, caveolae play a major role in signal transduction and appear to be veritable signalling platforms. In muscle cells, caveolae are essential for fusion and differentiation, and are also implicated in a type of muscular dystrophy (LGMD1C). In a preceding work, we demonstrated the presence of active milli-calpain (m-calpain) in myotube caveolae. Calpains are calcium-dependent proteases involved in several cellular processes, including myoblast fusion and migration, PKC-mediated intracellular signalling and remodelling of the cytoskeleton. For the first time, we have proved the cholesterol-dependent localisation of m-calpain in the caveolae of C(2)C(12) myotubes. Calpain-dependent caveolae involvement in myoblast fusion was also strongly suggested. Furthermore, eight differentially expressed caveolae associated proteins were identified by 2-DE and LC-MS/MS analyses using an m-calpain antisense strategy. This proteomic study also demonstrates the action of m-calpain on vimentin, desmin and vinculin in myotube caveolae and suggests m-calpain's role in several mitochondrial pathways.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Blotting, Western
  • Calpain / metabolism*
  • Caveolae / metabolism*
  • Chromatography, Liquid
  • Electrophoresis, Gel, Two-Dimensional
  • Immunohistochemistry
  • Molecular Sequence Data
  • Muscle Fibers, Skeletal / drug effects
  • Muscle Fibers, Skeletal / metabolism*
  • Protein Kinase C / metabolism
  • Proteome*
  • RNA, Antisense / pharmacology
  • Signal Transduction
  • Tandem Mass Spectrometry

Substances

  • Proteome
  • RNA, Antisense
  • Protein Kinase C
  • Calpain