Acute pathophysiological effects of muscle-expressed Dp71 transgene on normal and dystrophic mouse muscle.

products of the dystrophin gene range from the 427-kDa full-length dystrophin to the 70.8-kDa Dp71. Dp427 is expressed in skeletal muscle, where it links the actin cytoskeleton with the extracellular matrix via a complex of dystrophin-associated proteins (DAPs).

Exogenous Dp71 is a dominant negative competitor of dystrophin in skeletal muscle.

Dystrophin, the protein which is absent or non-functional in Duchenne muscular dystrophy, consists of four main domains: an N-terminal actin binding domain, a rod shaped domain of spectrin-like repeats, a cysteine-rich domain and a unique C-terminal domain. In muscle, dystrophin forms a linkage between the cytoskeletal actin and a group of membrane proteins (dystrophin associated proteins). The N-terminal domain binds to the cytoskeletal actin and the association with the dystrophin associated proteins is mediated mainly by the cysteine-rich and C-terminal domains of dystrophin.