Syntrophin

Thesyntrophinsare a family of five 60-kiloDaltonproteinsthat are associated withdystrophin,the protein associated withDuchenne muscular dystrophyandBecker muscular dystrophy.The name comes from the Greek wordsyntrophos,meaning "companion." The five syntrophins are encoded by separategenesand are termedα,β₁,β₂,γ₁,andγ₂.Syntrophin was first identified as a dystrophin-associated protein present in theTorpedoelectric organ(originally called "58K protein" ). Subsequently, α-syntrophin was shown to be the predominantisoforminskeletal musclewhere it is localized on thesarcolemmaand enriched at theneuromuscular junction.The β-syntrophins and γ₂-syntrophin are also present in skeletal muscle but also are in most other tissues. The expression of γ₁-syntrophin is mostly confined to brain. The syntrophins areadaptor proteinsthat use their multiple protein interactiondomains(twopleckstrin homology domainsand aPDZ domain) to localize a variety ofsignaling proteins(kinases,ion channels,water channels,nitric oxide synthase) to specific intracellular locations. α-Syntrophin binds tonNOSin thedystrophin-associated glycoprotein complexin skeletal muscle cells. There it producesNOupon muscle contraction leading to dilation of the arteries in the local area.

External links

• syntrophinat the U.S. National Library of MedicineMedical Subject Headings(MeSH)