TI  - A potential interaction of  <prot>p75</prot>  and  <prot>trkA</prot> <prot>NGF</prot> receptors  revealed by affinity
      crosslinking and immunoprecipitation.
PG  - 557-63
AB  -   <prot>Nerve growth factor</prot>   binds independently to two transmembrane receptors,
      the  <prot><prot>p75</prot> neurotrophin receptor</prot>  and the  <prot><prot>p140trk</prot> (<prot>trkA</prot>) tyrosine kinase
      receptor</prot> , which are both co-expressed in the majority of neuronal cells
      that respond to <prot>NGF</prot>. Previous findings have suggested that appropriate
      co-expression of the two receptors gives rise to high affinity <prot>NGF</prot> binding
      sites and increased neurotrophin responsiveness; however, evidence
      demonstrating a direct interaction between the two receptors in cell lines
      has been lacking. Here we have utilized affinity crosslinking agents with
      125I-NGF to detect an association of  <prot>trkA</prot>  and  <prot>p75</prot>  receptors in embryonic
      spinal cord and brain tissues enriched in the two receptors. Although
      multimeric complexes of <prot>trkA</prot> and <prot>p75</prot> were not detected by affinity
      crosslinking, immunoprecipitation of cross-linked <prot><prot>NGF</prot>-receptor</prot> complexes
      with <prot>trk</prot>-specific antibodies resulted in selective immunoprecipitation of
      crosslinked <prot>p75</prot>. Our results indicate that the  <prot>trkA</prot>  and  <prot>p75</prot> receptors  can
      potentially interact, and that such an association may be responsible for
      the generation of high affinity <prot>NGF</prot> binding sites.
AD  - Department of Cell Biology and Anatomy, Cornell University Medical
