Download MendeleyStructural and mechanistic insights into nerve growth factor interactions with the TrkA and p75 receptors.
Wehrman, T., He, X., Raab, B., Dukipatti, A., Blau, H., Garcia, K.C.(2007) Neuron 53: 25-38
- PubMed: 17196528
- DOI: https://doi.org/10.1016/j.neuron.2006.09.034
- Primary Citation of Related Structures:
2IFG - PubMed Abstract:
Nerve growth factor engages two structurally distinct transmembrane receptors, TrkA and p75, which have been proposed to create a "high-affinity" NGF binding site through formation of a ternary TrkA/NGF/p75 complex. To define a structural basis for the high-affinity site, we have determined the three-dimensional structure of a complete extracellular domain of TrkA complexed with NGF. The complex reveals a crab-shaped homodimeric TrkA structure, but a mechanism for p75 coordination is not obvious. We investigated the heterodimerization of membrane-bound TrkA and p75, on intact mammalian cells, using a beta-gal protein-protein interaction system. We find that NGF dimerizes TrkA and that p75 exists on the cell surface as a preformed oligomer that is not dissociated by NGF. We find no evidence for a direct TrkA/p75 interaction. We propose that TrkA and p75 likely communicate through convergence of downstream signaling pathways and/or shared adaptor molecules, rather than through direct extracellular interactions.
Organizational Affiliation:
Baxter Laboratory for Genetic Pharmacology, Department of Microbiology and Immunology, The Stem Cell Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
