Identification of a novel sarcoglycan gene at 5q33 encoding a sarcolemmal 35 kDa glycoprotein.
Mutations in any of the genes encoding the alpha, beta or gamma-sarcoglycan components of dystrophin-associated glycoproteins result in both sporadic and familial cases of either limb-girdle muscular dystrophy or severe childhood autosomal recessive muscular dystrophy. The collective name 'sarcoglycanopathies' has been proposed for these forms. We report the identification of a fourth member of the human sarcoglycan family. We named this novel cDNA delta-sarcoglycan. Its mRNA expression is abundant in striated and smooth muscles, with a main 8 kb transcript, encoding a predicted basic transmembrane glycoprotein of 290 amino acids. Antibodies specifically raised against this protein recognized a single band at 35 kDa on western blots of human and mouse muscle. Immunohistochemical staining revealed a unique sarcolemmal localization. FISH, radiation hybrid and YAC mapping concordantly linked the delta-sarcoglycan gene to 5q33, close to D5S487 and D5S1439. The gene spans at least 100 kb and is composed of eight exons. The identification of a novel sarcoglycan component modifies the current model of the dystrophin-glycoprotein complex.
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Istituto di Patologia Generale ed Oncologia, Facoltà di Medicina, Seconda Università degli Studi di Napoli, Italy.
Piluso
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Belsito
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Politano
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Puca
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AA
Papparella
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Rossi
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Viglietto
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Esposito
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Abbondanza
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Medici
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Molinari
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Nigro
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Puca
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002648:Child; D002874:Chromosome Mapping; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009132:Muscles / Q000378:metabolism; D009154:Mutation; D011817:Rabbits; D049031:Sarcoglycans; D012508:Sarcolemma / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D049031:Sarcoglycans