摘要
Specific binding of nerve growth factor (NGF) to p75 neurotrophin receptor (p75<sup>NTRsup>) leads to p75<sup>NTRsup> polyubiquitination and its subsequent interaction with TRAF6 resulting in neuronal cell survival. However, when the binding of NGF to p75<sup>NTRsup> was blocked with p75 antiserum, p75<sup>NTRsup> polyubiquitination and neuronal cell survival were impaired. Results showed that tyrosine phosphorylation of p75<sup>NTRsup> increased the polyubiquitination of p75<sup>NTRsup> and contributed to the observed apparent neuroprotective effects. Similar to p75<sup>NTRsup> polyubiquitination, interaction of TRAF6 with p75<sup>NTRsup> was NGF/tyrosine phosphorylation dependent suggesting that TRAF6 might function as an E3 ubiquitin ligase. In sum, the results show that specific binding of NGF to p75<sup>NTRsup> mediates neuronal cell survival.