Download MendeleyThe Cytoplasmic Adaptor Protein Dok7 Activates the Receptor Tyrosine Kinase MuSK via Dimerization.
Bergamin, E., Hallock, P.T., Burden, S.J., Hubbard, S.R.(2010) Mol Cell 39: 100-109
- PubMed: 20603078
- DOI: https://doi.org/10.1016/j.molcel.2010.06.007
- Primary Citation of Related Structures:
3ML4 - PubMed Abstract:
Formation of the vertebrate neuromuscular junction requires, among others proteins, Agrin, a neuronally derived ligand, and the following muscle proteins: LRP4, the receptor for Agrin; MuSK, a receptor tyrosine kinase (RTK); and Dok7 (or Dok-7), a cytoplasmic adaptor protein. Dok7 comprises a pleckstrin-homology (PH) domain, a phosphotyrosine-binding (PTB) domain, and C-terminal sites of tyrosine phosphorylation. Unique among adaptor proteins recruited to RTKs, Dok7 is not only a substrate of MuSK, but also an activator of MuSK's kinase activity. Here, we present the crystal structure of the Dok7 PH-PTB domains in complex with a phosphopeptide representing the Dok7-binding site on MuSK. The structure and biochemical data reveal a dimeric arrangement of Dok7 PH-PTB that facilitates trans-autophosphorylation of the kinase activation loop. The structure provides the molecular basis for MuSK activation by Dok7 and for rationalizing several Dok7 loss-of-function mutations found in patients with congenital myasthenic syndromes.
Organizational Affiliation:
Structural Biology Program, Kimmel Center for Biology and Medicine of the Skirball Institute and Department of Pharmacology, New York University School of Medicine, New York, NY 10016, USA.
