Functional interaction of Fas-associated phosphatase-1 (FAP-1) with p75(NTR) and their effect on NF-kappaB activation.
The common neurotrophin receptor p75(NTR), a member of the tumor necrosis factor (TNF) receptor superfamily, plays an important role in several cellular signaling cascades, including that leading to apoptosis. FAP-1 (Fas-associated phosphatase-1), which binds to the cytoplasmic tail of Fas, was originally identified as a negative regulator of Fas-mediated apoptosis. Here we have shown by co-immunoprecipitation that FAP-1 also binds to the p75(NTR) cytoplasmic domain in vivo through the interaction between the third PDZ domain of FAP-1 and C-terminal Ser-Pro-Val residues of p75(NTR). Furthermore, cells expressing a FAP-1/green fluorescent protein showed intracellular co-localization of FAP-1 and p75(NTR) at the plasma membrane. To elucidate the functional role of this physical interaction, we examined TRAF6 (TNF receptor-associated factor 6)-mediated NF-kappaB activation and tamoxifen-induced apoptosis in 293T cells expressing p75(NTR). The results revealed that TRAF6-mediated NF-kappaB activation was suppressed by p75(NTR) and that the p75(NTR)-mediated NF-kappaB suppression was reduced by FAP-1 expression. Interestingly, a mutant of the p75(NTR) intracellular domain with a single substitution of a Met for Val in its C-terminus, which cannot interact with FAP-1, displayed enhanced pro-apoptotic activity in 293T transfected cells. Thus, similar to Fas, FAP-1 may be involved in suppressing p75(NTR)-mediated pro-apoptotic signaling through its interaction with three C-terminal amino acids (tSPV). Thus, FAP-1 may regulate p75(NTR)-mediated signal transduction by physiological interaction through its third PDZ domain.
Irie
S
S
Molecular Oncology Laboratory, Tsukuba Life Science Center, Institute of Physical and Chemical Research (RIKEN), Ibaraki, Japan. irie@rtc.riken.go.jp
Hachiya
T
T
Rabizadeh
S
S
Maruyama
W
W
Mukai
J
J
Li
Y
Y
Reed
J C
JC
Bredesen
D E
DE
Sato
T A
TA
D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D015536:Down-Regulation; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D016296:Mutagenesis; D016328:NF-kappa B / Q000378:metabolism*; D010957:Plasmids; D011233:Precipitin Tests; D011485:Protein Binding; D054645:Protein Phosphatase 1; D054595:Protein Tyrosine Phosphatase, Non-Receptor Type 13; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism*; D015398:Signal Transduction; D048029:TNF Receptor-Associated Factor 6; D014162:Transfection; D015854:Up-Regulation
D002352:Carrier Proteins; D016328:NF-kappa B; D011506:Proteins; D020800:Receptor, Nerve Growth Factor; D048029:TNF Receptor-Associated Factor 6; D008156:Luciferases; D005982:Glutathione Transferase; D054645:Protein Phosphatase 1; C516742:PTPN13 protein, human; D054595:Protein Tyrosine Phosphatase, Non-Receptor Type 13; D017027:Protein Tyrosine Phosphatases