ε-Sarcoglycan, a Broadly Expressed Homologue of the Gene Mutated in Limb-Girdle Muscular Dystrophy 2D*
- From the Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
Abstract
The sarcoglycans are transmembrane components of the dystrophin-glycoprotein complex, which links the cytoskeleton to the extracellular matrix in adult muscle fibers. Mutations in all four known sarcoglycan genes (α, β, γ, and δ) have been found in humans with limb-girdle muscular dystrophy. We have identified a novel protein, ε-sarcoglycan, that shares 44% amino acid identity with α-sarcoglycan (adhalin). We show that ε-sarcoglycan is a membrane-associated glycoprotein and document its expression by Northern blotting, immunoblotting, and immunofluorescence. In contrast to α-δ sarcoglycans, which are expressed predominantly or exclusively in striated muscle, ε-sarcoglycan is broadly distributed in muscle and nonmuscle cells of both embryos and adults. These results raise the possibility that sarcoglycan-containing complexes mediate membrane-matrix interactions in many cell types.
Footnotes
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↵* This work was supported by grants from the National Institutes of Health and the Muscular Dystrophy Association (to J. R. S.) and a Jane Coffin Childs Fellowship (to G. F.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) AF031919 and AF031920.
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↵‡ To whom correspondence should be addressed: Dept. of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Ave., Box 8108, St. Louis, MO 63110. Fax: 314-747-1150; E-mail:sanesj{at}thalamus.wustl.edu.
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↵1 The abbreviations used are: DGC, dystrophin-glycoprotein complex; EST, expressed sequence tag; MOPS, 3-[N-morpholino]propanesulfonic acid; E, embryonic day; ORF, open reading frame; aa, amino acid(s).
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- Received September 11, 1997.
- Revision received October 17, 1997.
