Muscle, skeletal receptor tyrosine-protein kinase (MUSK)

Receptor tyrosine kinase that plays a central role in the formation and the maintenance of the neuromuscular junction (NMJ), the synapse between the motor neuron and the skeletal muscle (PubMed:25537362). Recruitment of AGRIN by LRP4 into the MUSK signaling complex induces phosphorylation and activation of MUSK, the kinase of the complex.

The activation of MUSK in myotubes modulates the formation of NMJs through the regulation of different procedures including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton as well as the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. May regulate AChR phosphorylation and clustering through activation of ABL1 and Src family kinases which in turn regulate MUSK.