Xenbase Image ID: 124447

Figure 8. Cortactin signaling in agrin-dependent AChR clustering: a model.Activation of MuSK by agrin induces AChR clustering in an actin polymerization-dependent manner. This model depicts a possible way in which cortactin signaling might promote the AChR clustering process. Initiation of intracellular signaling by the activated MuSK complex could enhance cortactin's tyrosine phosphorylation through src family tyrosine kinases (SFKs) (and possibly other kinases such as abl), and cortactin, in turn, could increase actin polymerization. Alternatively, cortactin might trigger actin polymerization by activating the Arp2/3 complex, either on its own or in concert with WASP-related proteins (N-WASP, WIP, etc.) to which it could be linked by the adapter Nck. In parallel, via other signaling intermediates, MuSK could stimulate Rho-family GTPases and, through them, F-actin assembly. Such enhanced and dynamic actin polymerization at synaptic sites could generate a scaffold which “traps” AChRs through rapsyn. Image published in: Madhavan R et al. (2009) Madhavan et al. This image is reproduced with permission of the journal and the copyright holder. This is an open-access article distributed under the terms of the Creative Commons Attribution license Larger Image Printer Friendly View

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