The Agrin/MuSK signaling pathway is spatially segregated from the neuregulin/ErbB receptor signaling pathway at the neuromuscular junction.

摘要: The neuregulin/erbB receptor and agrin/MuSK pathways are critical for communication between the nerve, muscle, Schwann cell that establishes precise topological arrangement at vertebrate neuromuscular junction (NMJ). ErbB2, erbB3, erbB4 as well neuregulin, agrin, MuSK known to be concentrated NMJ. Here we have examined NMJs from gastrocnemius muscle of adult rat using immunofluorescence confocal microscopy characterize in detail distribution these proteins relative acetylcholine receptors (AChRs). We determined erbB2 enriched depths secondary junctional folds on postsynaptic membrane. In contrast, erbB3 NMJ was presynaptic terminal cells. This strongly argues erbB2/erbB4 heterodimers functional neuregulin Neuregulin localized axon terminal, folds, cells, where it a position signal through erbB receptors. primary gutter region codistributed with AChRs. Agrin present basal lamina associated region, but not folds. differential distributions agrin signaling argue against being via direct interactions either or MuSK.