Muscle-specific receptor tyrosine-protein kinase (MuSK)

Muscle-specific receptor tyrosine-protein kinase (MuSK) is a ~100–120 kDa single-pass transmembrane receptor tyrosine kinase with an extracellular region containing three Ig-like domains and a cysteine-rich Frizzled-like domain, followed by a tyrosine kinase domain in the cytoplasm[1][2]. MuSK is central to NMJ formation, driving acetylcholine receptor (AChR) clustering and postsynaptic membrane specialization in response to agrin secreted by motor neurons, through interactions with LRP4 and Dok7[1][2][3]. MuSK is essential for muscle contraction and synaptic stability; knockout models die at birth due to failed NMJ formation[2]. Pathologically, it is targeted by autoantibodies in a subset of Myasthenia Gravis patients (MuSK-MG), making it an important therapeutic and diagnostic target[1].

Other names

Muscle associated receptor tyrosine kinaseMuscle, skeletal receptor tyrosine-protein kinaseMuscle-specific kinase receptorMuscle-specific tyrosine-protein kinase receptorCMS9FADSFADS1MuSK

Immunomodulation (e.g., B cell depletion with rituximab reduces MuSK autoantibodies); Suppression of antibody production with immunosuppressive drugs.