DYSTROPHIN

'Dystrophin' is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex. Many muscle proteins, such as α-dystrobrevin, syncoilin, synemin, sarcoglycan, dystroglycan, and sarcospan, colocalize with dystrophin at the costamere.
Dystrophin has the longest gene known to date, measuring 2.5 megabases (0.1% of the human genome). Its gene's locus is Xp21 and has 79 exons, produces an mRNA of 14.6 kilobases and a protein of over 3500 amino acid residues.

Contents

Pathology

References and notes

External links

Pathology

Its deficiency is one of the root causes of muscular dystrophy. It was first identified in 1987 by Louis M. Kunkel ^[1],
after the 1986 discovery of the mutated gene that causes Duchenne muscular dystrophy (DMD)
^[2].
Normal tissue contains small amounts of dystrophin (about 0.002% of total muscle protein), but its absence leads to both DMD and fibrosis, a condition of muscle hardening. A different mutation of the same gene causes defective dystrophin, leading to Becker's muscular dystrophy (BMD).

References and notes

1. Dystrophin: the protein product of the Duchenne muscular dystrophy locus, Hoffman E, Brown R, Kunkel L, , , Cell, 1987
2. Isolation of candidate cDNAs for portions of the Duchenne muscular dystrophy gene, Monaco A, Neve R, Colletti-Feener C et al, , , Nature, 1986

External links

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