Neuromuscular synapse formation requires a complex exchange of signals between motor neurons and skeletal muscle fibers, leading to the accumulation of postsynaptic proteins, including acetylcholine receptors in the muscle membrane and specialized release sites, or active zones in the presynaptic nerve terminal. MuSK, a receptor tyrosine kinase that is expressed in skeletal muscle, and Agrin, a...

BACKGROUND Anti-muscle specific kinase antibody positive myasthenia gravis (MuSK MG) is often characterized by a relatively severe and progressive course, refractoriness to standard myasthenia gravis (MG) medications, and an increased risk of myasthenic crisis. We report here successful management of three MuSK MG patients using maintenance therapeutic plasma exchange (TPE) treatment for up to ...

The muscle-specific receptor tyrosine kinase (MuSK) is part of a receptor complex, activated by neural agrin, that orchestrates the differentiation of the neuromuscular junction (NMJ). To gain insight into the function of the MuSK complex, we have developed a proteomic approach to identify new MuSK partners. MS analysis of MuSK crosslink products from postsynaptic membranes of the Torpedo elect...

Diarrhea constitutes one of the most common diseases affecting the survival of captive musk deer and is usually caused by an imbalance in intestinal microbiota. Currently, research regarding the structure and function of intestinal microbiota in diarrheic musk deer is lacking. Therefore, in the present study, high-throughput 16S-rRNA gene sequencing was used to analyze the intestinal microbiota...

To determine if patients with myasthenia gravis (MG) have antibodies to agrin, a proteoglycan released by motor neurons and is critical for neuromuscular junction (NMJ) formation, we collected serum samples from 93 patients with MG with known status of antibodies to acetylcholine receptor (AChR), muscle specific kinase (MuSK) and lipoprotein-related 4 (LRP4) and samples from control subjects (h...

CollagenQ (ColQ) plays an important structural role at vertebrate neuromuscular junctions (NMJs) by anchoring and accumulating acetylcholinesterase (AChE) in the extracellular matrix (ECM). Moreover, ColQ interacts with perlecan/dystroglycan and the muscle-specific receptor tyrosine kinase (MuSK), key molecules in the NMJ formation. MuSK promotes acetylcholine receptor (AChR) clustering in a pr...

Synaptogenesis at the neuromuscular junction requires agrin-induced stable localization of acetylcholine receptors (AChRs) at the endplate. The effects of agrin are transduced by the muscle-specific receptor tyrosine kinase (MuSK). This study provides evidence that Src-class protein tyrosine kinases mediate the effects of agrin-activated MuSK to regulate clustering and anchoring of AChRs in ske...

MuSK is a receptor tyrosine kinase expressed selectively in skeletal muscle and localized to neuromuscular synapses. Agrin activates MuSK and stimulates phosphorylation and clustering of acetylcholine receptors (AChRs) at synaptic sites. We expressed wild-type or mutant MuSK in MuSK(-/-) myotubes and identified tyrosine residues in the MuSK cytoplasmic domain that are necessary for agrin-stimul...

Formation of the neuromuscular junction (NMJ) depends upon a nerve-derived protein, agrin, acting by means of a muscle-specific receptor tyrosine kinase, MuSK, as well as a required accessory receptor protein known as MASC. We report that MuSK does not merely play a structural role by demonstrating that MuSK kinase activity is required for inducing acetylcholine receptor (AChR) clustering. We a...

The muscle-specific kinase MuSK is part of an agrin receptor complex that stimulates tyrosine phosphorylation and drives clustering of acetylcholine receptors (AChRs) in the postsynaptic membrane at the vertebrate neuromuscular junction (NMJ). MuSK also regulates synaptic gene transcription in subsynaptic nuclei. Over the past few years, decisive progress has been made in the identification of ...