Costamere
Appearance
The costamere is a structural-functional component of skeletal muscle cells which, according to original descriptions in the early 1980s (which are generally still accepted), are sub-sarcolemmal protein assemblies circumferentially aligned in register with the Z-disk of peripheral myofibrils. They physically couple force-generating sarcomeres with the sarcolemma in striated muscle cells and are thus considered the "Achilles heel", i.e. the key vulnerable point of the muscle which are defective in many myopathies [1]
The costamere is also known as the dystrophin-associated protein complex (DAPC) as well as the dystroglycan complex, due to the presence of the proteins that are enriched there.
References
- ^ James M. Ervasti Costameres: the Achilles' Heel of Herculean Muscle J. Biol. Chem. 278: 13591-13594. http://www.jbc.org/cgi/content/full/278/16/13591