Nebulette binds to actin and plays an important role in Z-disk assembly. It is a cardiac homolog of nebulin and its expression is abundant in cardiac muscle. Nebulette defects are assocated with non-familial idiopathic cardiacmyopathy.
Nebulin and nebulette are homologous thin-filament associated proteins expressed in skeletal and cardiac muscles, respectively. Nebulette, unlike nebulin, is confined to the Z-disc region of the sarcomere and does not span the whole thin filament length. Nebulette colocalizes with α-actinin in the pre-, nascent, and mature myofibrils. A polymorphism in the actin-binding motif of nebulette is a genetic marker of susceptibility to nonfamilial idiopathic dilated cardiomyopathy (IDC), characterized by a thin-walled heart and systolic dysfunction.