Coordinate enrichment of cranin (dystroglycan) subunits in synaptic membranes of sheep brain.

Abstract Cranin (dystroglycan), a mucin-like extracellular matrix receptor comprised of two subunits (α and β), is involved in regulating cell–matrix interactions in a variety of tissues, including brain. A basic issue remains unresolved concerning the distribution of cranin in brain: are the α and β subunits coordinately expressed at the synapse? We report here that cranin is indeed enriched progressively in synaptosomes and synaptic membranes of sheep brain, as assessed by immunoblotting and laminin-blotting assays, and that the extent of enrichment is similar for both α and β subunits. These findings support the hypothesis that cranin (dystroglycan) contributes to synaptic function in the CNS.