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Updated: Jun 25, 2026

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Published on: March 16, 2009
Dok-7 activates the muscle receptor kinase MuSK and shapes synapse formation
Akane Inoue1, Kiyoko Setoguchi, Yosuke Matsubara
1Division of Genetics and Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan.
Abstract:
The formation of the neuromuscular junction (NMJ) is orchestrated by the muscle-specific receptor tyrosine kinase MuSK and by neural agrin, an extracellular activator of MuSK. We previously showed that the MuSK-interacting protein Dok-7 is essential for neuromuscular synaptogenesis, although the mechanisms by which Dok-7 regulates MuSK activity and promotes synapse formation have been unclear. Here, we show that Dok-7 directly interacts with the cytoplasmic portion of MuSK and activates the receptor tyrosine kinase, and that neural agrin requires Dok-7 to activate MuSK. In vivo overexpression of Dok-7 increased MuSK activation and promoted NMJ formation. Furthermore, Dok-7 was required for the localization of MuSK in the central region of muscle, which is essential for the correct formation of NMJs in this region. These observations indicate that Dok-7 positively regulates neuromuscular synaptogenesis by controlling MuSK activity, its distribution, and its responsiveness to neural agrin.
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