Dystrophin


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.

As of 2007, dystrophin is the longest gene known, covering 2.4 megabases (0.08% of the human genome) at locus Xp21. The primary transcript measures about 2,400 kilobases and takes 16 hours to transcribe, the mature mRNA measures 14.0 kilobases [ [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?val=NM_000109.2 NCBI Sequence Viewer v2.0 ] ] . The 79 exons [Strachan T and Read AP, 1999. Human molecular genetics, BIOS Scientific, New York, USA] code for a protein of over 3500 amino acid residues. [ [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?val=NP_000100.2 NCBI Sequence Viewer v2.0 ] ]

Pathology

Its deficiency is one of the root causes of muscular dystrophy. It was first identified in 1987 by Louis M. Kunkel [cite journal |author=Hoffman E, Brown R, Kunkel L |title=Dystrophin: the protein product of the Duchenne muscular dystrophy locus |journal=Cell |volume=51 |issue=6 |pages=919–28 |year=1987 |pmid=3319190 |doi=10.1016/0092-8674(87)90579-4] , after the 1986 discovery of the mutated gene that causes Duchenne muscular dystrophy (DMD) [cite journal |author=Monaco A, Neve R, Colletti-Feener C et al |title=Isolation of candidate cDNAs for portions of the Duchenne muscular dystrophy gene |journal=Nature |volume=323 |issue=6089 |pages=646–50 |year=1986 |pmid=3773991 |doi=10.1038/323646a0] .

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).

Though its role in airway smooth muscle is not well established recent research indicates that dystrophin along with other subunits of dystrophin glycoprotein complex is associated with phenotype maturation. [cite journal |author=Sharma P, Tran T, Stelmack GL, "et al" |title=Expression of the dystrophin-glycoprotein complex is a marker for human airway smooth muscle phenotype maturation |journal=Am. J. Physiol. Lung Cell Mol. Physiol. |volume=294 |issue=1 |pages=L57–68 |year=2008 |pmid=17993586 |doi=10.1152/ajplung.00378.2007 |url=]

References

Further reading

PBB_Further_reading
citations =
*cite journal | author=Roberts RG, Gardner RJ, Bobrow M |title=Searching for the 1 in 2,400,000: a review of dystrophin gene point mutations |journal=Hum. Mutat. |volume=4 |issue= 1 |pages= 1–11 |year= 1994 |pmid= 7951253 |doi= 10.1002/humu.1380040102
*cite journal | author=Tinsley JM, Blake DJ, Zuellig RA, Davies KE |title=Increasing complexity of the dystrophin-associated protein complex |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=91 |issue= 18 |pages= 8307–13 |year= 1994 |pmid= 8078878 |doi= 10.1073/pnas.91.18.8307
*cite journal | author=Blake DJ, Weir A, Newey SE, Davies KE |title=Function and genetics of dystrophin and dystrophin-related proteins in muscle |journal=Physiol. Rev. |volume=82 |issue= 2 |pages= 291–329 |year= 2002 |pmid= 11917091 |doi= 10.1152/physrev.00028.2001 |doi_brokendate=2008-06-22
*cite journal | author=Röper K, Gregory SL, Brown NH |title=The 'spectraplakins': cytoskeletal giants with characteristics of both spectrin and plakin families |journal=J. Cell. Sci. |volume=115 |issue= Pt 22 |pages= 4215–25 |year= 2003 |pmid= 12376554 |doi=
*cite journal | author=Muntoni F, Torelli S, Ferlini A |title=Dystrophin and mutations: one gene, several proteins, multiple phenotypes |journal=Lancet neurology |volume=2 |issue= 12 |pages= 731–40 |year= 2003 |pmid= 14636778 |doi= 10.1016/S1474-4422(03)00585-4
*cite journal | author=Haenggi T, Fritschy JM |title=Role of dystrophin and utrophin for assembly and function of the dystrophin glycoprotein complex in non-muscle tissue |journal=Cell. Mol. Life Sci. |volume=63 |issue= 14 |pages= 1614–31 |year= 2006 |pmid= 16710609 |doi= 10.1007/s00018-005-5461-0

External links

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Look at other dictionaries:

  • Dystrophin — Masse/Länge Primärstruktur 3685 Aminosäuren …   Deutsch Wikipedia

  • dystrophin — dystrophin. См. дистрофин. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • dystrophin — A protein found in the sarcolemma of normal muscle; it is missing in individuals with pseudohypertrophic muscular dystrophy and in other forms of muscular dystrophy; its role may be in the linkage of the …   Medical dictionary

  • dystrophin — noun Etymology: dystrophy + 1 in Date: 1987 a protein that is associated with a transmembrane complex of skeletal muscle cells and that is absent in Duchenne muscular dystrophy and deficient or defective in Becker muscular dystrophy …   New Collegiate Dictionary

  • dystrophin — Protein (400 kD) from skeletal muscle that is missing in Duchenne muscular dystrophy. Its exact role is not yet clear, though it seems to be associated with the cytoplasmic face of the sarcolemma and T tubules and may form part of the membrane… …   Dictionary of molecular biology

  • dystrophin — noun A cytoplasmic structural protein that is deficient in some forms of muscular dystrophy …   Wiktionary

  • dystrophin — [dɪs trəʊfɪn] noun Biochemistry a protein found in skeletal muscle, which is absent in sufferers from muscular dystrophy …   English new terms dictionary

  • dystrophin — dys·tro·phin …   English syllables

  • dystrophin — /dɪsˈtroʊfən/ (say dis trohfuhn) noun a cytoplasmic protein important in the maintenance of muscular structure …   Australian English dictionary

  • dystrophin — ˈdistrəˌfin noun ( s) Etymology: dystrophy + in : a protein of high molecular weight that is associated with a transmembrane glycoprotein complex of skeletal muscle cells and is absent in Duchenne muscular dystrophy and deficient or of abnormal… …   Useful english dictionary


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