The anatomy of a molecular giant: how the sarcomere cytoskeleton is assembled from immunoglobulin superfamily molecules.

Cross-striated muscle contains an elastic cytoskeleton comprised of the giant protein titin and several associated proteins. cDNA sequencing revealed that all these proteins are immunoglobulin superfamily members. This modular structure opens the possibility to dissect the proteins involved into functional units and to approach the problem of structure-function correlation at the molecular level.