The synaptic CT carbohydrate modulates binding and expression of extracellular matrix proteins in skeletal muscle: Partial dependence on utrophin.

摘要: The CT carbohydrate, Neu5Ac/Neu5Gcα2,3[GalNAcβ1,4]Galβ1,4GlcNAcβ-, is specifically expressed at the neuromuscular junction in skeletal myofibers of adult vertebrates. When Galgt2, glycosyltransferase that creates synaptic β1,4GalNAc portion this glycan, overexpressed extrasynaptic regions myofiber membrane, α dystroglycan becomes glycosylated with carbohydrate and coincides ectopic expression dystroglycan-binding proteins, including laminin α4, α5, utrophin. Here we show both forms agrin have increased binding to compared sialyl-N-acetyllactosamine, its extrasynaptically precursor. Muscle laminins also CT-glycosylated muscle relative non-CT-containing glycoforms. Overexpression Galgt2 transgenic mouse mRNA extracellular matrix (ECM) genes, as well utrophin, integrin α7, neuregulin. Increased ECM proteins muscles was partially dependent on but utrophin not required for Galgt2-induced changes growth or development. These experiments demonstrate overexpression a can increase muscle, they suggest mechanism by which may inhibit muscular dystrophy affect