Cytoskeletal defects in cardiomyopathy

Genetic studies of cardiomyopathy and muscular dystrophy have emphasized the importance of the striated myocyte cytoskeleton. Cytoskeletal defects produce myopathies through a combination of structural and signaling mechanisms. Broadly, the cytoskeletal proteins defective in these myopathic syndromes can be classified into categories based on their intracellular locations. The first category includes proteins of the plasma membrane that interact with both subsarcolemmal and extracellular matrix proteins. The second category, generally associated with hypertrophic cardiomyopathies, includes proteins of the sarcomere. The last, newly emerging, category includes proteins of the inner nuclear membrane. In this review, we will examine the genetic defects that lead to cardiomyopathy and the potential means by which these varied proteins normally maintain the structural integrity of myocytes.