Figure 4
MuSK antibodies specifically activate MuSK and the downstream cascade.
Specific phosphorylation of MuSK and AChR β subunit (AChRβ) by MuSK antibodies. C2C12 myotubes were treated with agrin or MuSK antibodies for 30 minutes and then immunoprecipitated with (A) MuSK antibodies or (B) biotinylated BTX using streptavidin-Sepharose. Immunoblots of immunoprecipitates were probed with antibodies to MuSK (A), AChRβ (B), or phosphotyrosine (PY, A and B). Both MuSK and AChRβ were phosphorylated after the treatment of agrin or MuSK antibodies. Phosphorylation of MuSK and AChRβ was inhibited by the absorption of MuSK antibodies with MuSK-AP protein.
