English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Dimerization of the muscle-specific kinase induces tyrosine phosphorylation of acetylcholine receptors and their aggregation on the surface of myotubes

MPS-Authors
/persons/resource/persons292652

Hopf,  C       
Department Biochemistry, Max Planck Institute for Developmental Biology, Max Planck Society;

/persons/resource/persons282991

Hoch,  W
Department Biochemistry, Max Planck Institute for Developmental Biology, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Hopf, C., & Hoch, W. (1998). Dimerization of the muscle-specific kinase induces tyrosine phosphorylation of acetylcholine receptors and their aggregation on the surface of myotubes. The Journal of Biological Chemistry, 273(11), 6467-6473. doi:10.1074/jbc.273.11.6467.


Cite as: https://hdl.handle.net/21.11116/0000-000D-C153-B
Abstract
During development of the neuromuscular junction, neuronal splice variants of agrin initiate the aggregation of acetylcholine receptors on the myotube surface. The muscle-specific kinase is thought to be part of an agrin receptor complex, although the recombinant protein does not bind agrin with high affinity. To specify its function, we induced phosphorylation and activation of this kinase in the absence of agrin by incubating myotubes with antibodies directed against its N-terminal sequence. Antibody-induced dimerization of the muscle-specific kinase but not treatment with Fab fragments was sufficient to trigger two key events of early postsynaptic development: acetylcholine receptors accumulated into aggregates, and their beta-subunits became phosphorylated on tyrosine residues. Heparin partially inhibited receptor aggregation induced by both agrin and anti-muscle-specific kinase antibodies. In contrast, it did not affect kinase or acetylcholine receptor phosphorylation. These data indicate that agrin induces postsynaptic differentiation by dimerizing the muscle-specific kinase. They also suggest that activation of the kinase domain can account for only part of agrin's effects. Dimerization of this molecule appears to activate an additional signal, most likely by organizing a scaffold for other postsynaptic proteins.