Detection of O-mannosyl glycans in rabbit skeletal muscle alpha-dystroglycan.
alpha-Dystroglycan, which is a cell surface component of dystroglycan complex, is known to bind laminin in basal lamina of muscle cells and Schwann cells. We found previously that a novel O-glycan, Siaalpha2-3Galbeta1-4GlcNAcbeta1-2Man, is the major oligosaccharide in bovine peripheral nerve alpha-dystroglycan, and that this structure might mediate the binding of laminin. In order to determine whether this structure is specific for peripheral nerve alpha-dystroglycan or present on different forms of alpha-dystroglycan, we analyzed the structures of the sialylated O-glycans of rabbit skeletal muscle alpha-dystroglycan. Their structures were elucidated to be a mixture of a core 1 O-glycan and the same O-mannosyl glycan that we found in bovine peripheral nerve. These results indicate that alpha-dystroglycan in different species and tissues share a common structure of its major O-linked acidic carbohydrate, suggesting its relevance to the basic functional role of alpha-dystroglycan.
Sasaki
T
T
Department of Glycobiology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan.
Yamada
H
H
Matsumura
K
K
Shimizu
T
T
Kobata
A
A
Endo
T
T
D000818:Animals; D003598:Cytoskeletal Proteins / Q000737:chemistry*; D049030:Dystroglycans; D007797:Laminin / Q000378:metabolism; D008358:Mannose / Q000032:analysis*; D008562:Membrane Glycoproteins / Q000737:chemistry*; D018482:Muscle, Skeletal / Q000378:metabolism*; D011134:Polysaccharides / Q000032:analysis*; D011817:Rabbits; D062367:ortho-Aminobenzoates
D003598:Cytoskeletal Proteins; D007797:Laminin; D008562:Membrane Glycoproteins; D011134:Polysaccharides; D062367:ortho-Aminobenzoates; D049030:Dystroglycans; D008358:Mannose; C000219:anthranilamide