Probable muscle-intrinsic activator of MUSK that plays an essential role in neuromuscular synaptogenesis. Acts in aneural activation of MUSK and subsequent acetylcholine receptor (AchR) clustering in myotubes. Induces autophosphorylation of MUSK. Homodimer (By similarity). Forms a heterotetramer composed of 2 DOK7 and 2 MUSK molecules which facilitates MUSK trans-autophosphorylation on tyrosine residue and activation (By similarity). Interacts (via IRS-type PTB domain) with MUSK (via cytoplasmic part); requires MUSK phosphorylation. Accumulates at neuromuscular junctions. Preferentially expressed in skeletal muscle and heart. Present in thigh muscle, diaphragm and heart but not in the liver or spleen (at protein level). The PH domain mediated binding to phospholipids with phosphoinositol headgroups. Affinity is highest for phosphatidyl 3,4,5-trisphosphate, followed by phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 4,5-bisphosphate (By similarity). The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Contains a poly-A tail in the 5'region. Leiden Open Variation Database (LOVD)