Caveolin-3 is not an integral component of the dystrophin glycoprotein complex

FEBS Lett. 1998 May 8;427(2):279-82. doi: 10.1016/s0014-5793(98)00442-6.

Abstract

The dystrophin-glycoprotein complex is a multi-subunit protein complex that spans the muscle plasma membrane (sarcolemma) and forms a link between the intracellular cytoskeleton and the extracellular matrix. Caveolin-3, the muscle specific form of caveolin, is also a major structural and regulatory integral membrane protein found at the sarcolemma. Oligomers of caveolin-3 form the structural framework for small membrane pockets known as caveolae. We directly examined whether caveolin-3 is an integral component of the dystrophin-glycoprotein complex by examining four common biochemical and cellular properties of proteins integrally bound to the dystrophin-glycoprotein complex. We found that caveolin-3 de-enriches with partial purification of the dystrophin-glycoprotein complex although a small amount of caveolin-3 is present. Sucrose gradient fractionation and laminin affinity chromatography completely separate this residual caveolin-3 from the core components of the dystrophin-glycoprotein complex. We also show that caveolin-3 expression at the sarcolemma is not reduced in patients with primary mutations in either dystrophin or the sarcoglycans. This data demonstrates that localization of caveolin-3 to the sarcolemma occurs independently of the dystrophin-glycoprotein complex and that caveolin-3 is not an integral component of the dystrophin-glycoprotein complex.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Caveolin 3
  • Caveolins*
  • Chromatography, Affinity / methods
  • Cytoskeletal Proteins / analysis
  • Dystroglycans
  • Dystrophin / analysis
  • Dystrophin / chemistry*
  • Humans
  • Laminin
  • Macromolecular Substances
  • Membrane Glycoproteins / analysis
  • Membrane Glycoproteins / chemistry*
  • Membrane Proteins / analysis*
  • Mice
  • Mice, Inbred mdx
  • Muscle, Skeletal / chemistry
  • Muscular Dystrophies
  • Rabbits
  • Sarcolemma / chemistry

Substances

  • Cav3 protein, mouse
  • Caveolin 3
  • Caveolins
  • Cytoskeletal Proteins
  • DAG1 protein, human
  • Dystrophin
  • Laminin
  • Macromolecular Substances
  • Membrane Glycoproteins
  • Membrane Proteins
  • Dystroglycans