Dystroglycan glycosylation and its role in alpha-dystroglycanopathies.

Glycosylation is the most common post-translational modification of proteins. The protein sequence data suggested that more than half of all proteins produced in mammalian cells are glycoproteins. Glycans of secreted glycoproteins affect many protein properties such as solubility, stability, protease sensitivity, and polarity, while glycans on cell surface glycoproteins are involved in various cellular functions including cell-cell and cell-matrix interactions during embryogenesis, immune reactions, and tumor development. The past decade of research on glycan function has revealed the etiology of a growing number of human genetic diseases with aberrant glycan formation. This review focuses upon the involvement of O-mannosylglycan in the molecular and cellular mechanisms of muscular dystrophies. Advances in glycobiology are expected to result in a better understanding and in improved treatments of a class of muscular dystrophies called alpha-dystroglycanopathies.