Amyloid β Binds Trimers as Well as Monomers of the 75-kDa Neurotrophin Receptor and Activates Receptor Signaling

Mina Yaar, Sen Zhai, Richard E. Fine, Patricia B. Eisenhauer, Bennett L. Arble, Kenneth B. Stewart, Barbara A. Gilchrest
2001 Journal of Biological Chemistry  
p75 NTR , a nerve growth factor co-receptor that has been implicated in apoptosis of neurons, is structurally related to Fas and the receptors for tumor necrosis factor-␣ that display ligand independent assembly into trimers. Using embryonic day 17 fetal rat cortical neurons and p75 NTR -expressing NIH-3T3 cells, we now show that p75 NTR exists as a trimer as well as a monomer. Furthermore, we have reported and others have confirmed that amyloid ␤ binds p75 NTR , and that this binding leads to
more » ... poptotic cell death. We now report that amyloid ␤ binds to trimers of p75 NTR as well as to p75 NTR monomers but not to the p140 trkA , the nerve growth factor co-receptor that mediates neuronal survival. Furthermore, amyloid ␤ activates p75 NTR , strongly inducing the transcription of c-Jun mRNA and stimulating the stress-activated c-Jun NH 2 -terminal kinase, as measured by phosphorylation of its substrate (glutathione S-transferase-c-Jun-(1-79)). Our data suggest that p75 NTR may be present as a preformed trimer that binds amyloid ␤ to induce receptor activation, and support the hypothesis that p75 NTR activation by amyloid ␤ is causally related to Alzheimer's disease.
doi:10.1074/jbc.m110929200 pmid:11756426 fatcat:c2zqgg5evbao7hzkwkvpx2dfvy