Human Muscle Associated Receptor Tyrosine Kinase (MUSK) Protein

Background

Muscle-associated receptor tyrosine kinase (MUSK) is a critical protein in the formation and maintenance of the neuromuscular junction (NMJ), the synapse between motor neurons and muscle fibers. MUSK is essential for the proper functioning of the NMJ, playing a pivotal role in the signaling pathways that govern the assembly and stability of this specialized synapse. The NMJ is crucial for muscle contraction and overall motor function, and disruptions in MUSK function can lead to severe neuromuscular diseases. MUSK is encoded by the MUSK gene, located on chromosome 9 in humans. The protein belongs to the receptor tyrosine kinase family and is highly conserved across species, reflecting its essential role in muscle biology. MUSK activation is tightly regulated and involves interactions with several other proteins, including agrin, low-density lipoprotein receptor-related protein 4 (LRP4), and downstream effectors such as rapsyn.