Dystrophin

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dystrophin (muscular dystrophy, Duchenne and Becker types)
Identifiers
Symbol	DMD
HUGO	2928
Entrez	1756
OMIM	300377
RefSeq	NM_004006
UniProt	P11532
Other data
Locus	Chr. X p21.2

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.

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.

[edit] 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).

[edit] References and notes

1. ^ Hoffman et al., Cell. 1987 Dec 24;51(6):919-928
2. ^ Monaco et al., Nature. 1986 Oct 16-22;323(6089):646-650

[edit] External links

• MeSH Dystrophin