Upon activation by its ligandagrin,[5] MuSK signals via the proteins calledcasein kinase 2 (CK2),[6]Dok-7[7] andrapsyn, to induce "clustering" of acetylcholine receptors (AChR). Both CK2 and Dok-7 are required for MuSK-induced formation of theneuromuscular junction, since mice lacking Dok-7 failed to form AChR clusters or neuromuscular synapses, and since downregulation of CK2 also impedes recruitment of AChR to the primary MuSK scaffold. In addition to the proteins mentioned, other proteins are then gathered, to form the endplate to the neuromuscular junction. The nerve terminates onto the endplate, forming the neuromuscular junction - a structure required to transmit nerve impulses to the muscle, and thus initiating muscle contraction.
Antibodies directed against this protein (Anti-MuSK autoantibodies) are found in some people withmyasthenia gravis not demonstrating antibodies to theacetylcholine receptor.[8] The disease still causes loss of acetylcholine receptor activity,[9] but the symptoms affected people experience may differ from those of people with other causes of myasthenia gravis.[citation needed]
^Hoch W, McConville J, Helms S, Newsom-Davis J, Melms A, Vincent A (Mar 2001). "Auto-antibodies to the receptor tyrosine kinase MuSK in patients with myasthenia gravis without acetylcholine receptor antibodies".Nature Medicine.7 (3):365–8.doi:10.1038/85520.PMID11231638.S2CID18641849.
^Barrett-Jolley R, Byrne N, Vincent A, Newsom-Davis J (Oct 1994). "Plasma from patients with seronegative myasthenia gravis inhibit nAChR responses in the TE671/RD cell line".Pflügers Archiv.428 (5–6):492–8.doi:10.1007/BF00374570.PMID7838671.S2CID5611563.
