کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2199453 | 1099449 | 2006 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Defective neuromuscular synaptogenesis in mice expressing constitutively active ErbB2 in skeletal muscle fibers Defective neuromuscular synaptogenesis in mice expressing constitutively active ErbB2 in skeletal muscle fibers](/preview/png/2199453.png)
We overexpressed a constitutively active form of the neuregulin receptor ErbB2 (CAErbB2) in skeletal muscle fibers in vivo and in vitro by tetracycline-inducible expression. Surprisingly, CAErbB2 expression during embryonic development was lethal and impaired synaptogenesis yielding a phenotype with loss of synaptic contacts, extensive axonal sprouting, and diffuse distribution of acetylcholine receptor (AChR) transcripts, reminiscent of agrin-deficient mice. CAErbB2 expression in cultured myotubes inhibited the formation and maintenance of agrin-induced AChR clusters, suggesting a muscle- and not a nerve-origin for the defect in CAErbB2-expressing mice. Levels of tyrosine phosphorylated MuSK, the signaling component of the agrin receptor, were similar, while tyrosine phosphorylation of AChRβ subunits was dramatically reduced in CAErbB2-expressing embryos relative to controls. Thus, a gain-of-function manipulation of ErbB2 signaling pathways renders an agrin-deficient-like phenotype that uncouples MuSK and AChR tyrosine phosphorylation.
Journal: Molecular and Cellular Neuroscience - Volume 31, Issue 2, February 2006, Pages 334–345