Abstract
Dystroglycan is a cytoskeleton-linked extracellular matrix receptor expressed in many cell types. Dystroglycan is composed of alpha- and beta-subunits which are encoded by a single mRNA. Using a heterologous mammalian expression system, we provide the first biochemical evidence of the alpha/beta-dystroglycan precursor propeptide prior to enzymatic cleavage. This 160 kDa dystroglycan propeptide is processed into alpha- and beta-dystroglycan (120 kDa and 43 kDa, respectively). We also demonstrate that the precursor propeptide is glycosylated and that blockade of asparagine-linked (N-linked) glycosylation did not prevent the cleavage of the dystroglycan precursor peptide. However, inhibition of N-linked glycosylation results in aberrant trafficking of the alpha- and beta-dystroglycan subunits to the plasma membrane. Thus, dystroglycan is synthesized as a precursor propeptide that is post-translationally cleaved and differentially glycosylated to yield alpha- and beta-dystroglycan.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amidohydrolases / metabolism
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Amino Acid Sequence
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Animals
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CHO Cells
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Cell Membrane / metabolism
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Cricetinae
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Culture Media, Conditioned / metabolism
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Cytomegalovirus / genetics
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Cytoskeletal Proteins / biosynthesis*
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Cytoskeletal Proteins / genetics
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Dystroglycans
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Electrophoresis, Polyacrylamide Gel
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Genetic Vectors
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Glycosylation
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Immunoblotting
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Membrane Glycoproteins / biosynthesis*
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Membrane Glycoproteins / genetics
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Molecular Sequence Data
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Molecular Weight
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Oligosaccharides / metabolism
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Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
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Peptides / metabolism*
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Protein Precursors / metabolism*
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Protein Processing, Post-Translational*
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RNA, Messenger / metabolism
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Rabbits
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Transfection
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Tunicamycin / metabolism
Substances
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Culture Media, Conditioned
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Cytoskeletal Proteins
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Membrane Glycoproteins
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Oligosaccharides
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Peptides
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Protein Precursors
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RNA, Messenger
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Tunicamycin
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Dystroglycans
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Amidohydrolases
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Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase