Agrin is a high-affinity binding protein of dystroglycan in non-muscle tissue

摘要: Agrin is a basement membrane-associated proteoglycan that induces the formation of postsynaptic specializations at neuromuscular junction. This activity modulated by alternative splicing and thought to be mediated receptors expressed in muscle fibers. An isoform agrin does not induce binds with high affinity dystroglycan, component dystrophin-glycoprotein complex. Transcripts encoding this are variety non-muscle tissues. Here, we analyzed tissue distribution dystroglycan on protein level determined their binding affinities. We found most abundant lung, kidney, brain. Only little was detected skeletal muscle, no liver. Dystroglycan highly all tissues examined except In solid-phase radioligand assay, bound from dissociation constant between 1.8 2.2 nM, while brain-derived 4.6 nM. adult kidney co-purified co-immunoprecipitated both molecules were co-localized embryonic tissue. These data show high-affinity partner they suggest interaction, like laminin may important for mechanical integrity