Dp71

Dp71 is a 71-kilodalton isoform of dystrophin produced from the DMD gene by alternative promoters and splicing. Unlike the full-length dystrophin Dp427, which is abundant in skeletal and cardiac muscle, Dp71 is predominantly expressed in non-muscle tissues, with high levels in the brain and retina and lower levels in other tissues.

In humans, Dp71 is detected in neurons and glia, as well as in various epithelial and vascular tissues. It is a component of the dystrophin-associated protein complex (DAPC) in non-muscle cells, helping to link the cytoskeleton to the extracellular matrix and to participate in signaling pathways. Through these interactions, Dp71 is thought to contribute to maintenance of membrane integrity, organization of synapses, and cellular signaling that affects brain development and function.

Research using Dp71-deficient models shows that loss of Dp71 can lead to altered brain development and cognitive and motor deficits, as well as changes in the expression of synaptic proteins. These findings support a role for Dp71 in the neurological and non-muscle symptoms associated with dystrophinopathies, even though the muscle-specific isoforms (like Dp427) are primarily linked to the muscular disease phenotype.

Clinical relevance: In Duchenne muscular dystrophy and related syndromes, mutations or deletions in the DMD gene that affect Dp71 expression or function can contribute to cognitive impairments and other non-muscle symptoms observed in patients. Ongoing research investigates Dp71’s functions and potential therapeutic implications for brain and other tissue manifestations of dystrophinopathies.

See also: DMD gene, dystrophin isoforms, dystrophin-associated protein complex.