First Author | Boutaffala L | Year | 2015 |
Journal | Cell Death Differ | Volume | 22 |
Issue | 12 | Pages | 2020-33 |
PubMed ID | 26045047 | Mgi Jnum | J:260868 |
Mgi Id | MGI:6141478 | Doi | 10.1038/cdd.2015.69 |
Citation | Boutaffala L, et al. (2015) NIK promotes tissue destruction independently of the alternative NF-kappaB pathway through TNFR1/RIP1-induced apoptosis. Cell Death Differ 22(12):2020-33 |
abstractText | NF-kappaB-inducing kinase (NIK) is well-known for its role in promoting p100/NF-kappaB2 processing into p52, a process defined as the alternative, or non-canonical, NF-kappaB pathway. Here we reveal an unexpected new role of NIK in TNFR1-mediated RIP1-dependent apoptosis, a consequence of TNFR1 activation observed in c-IAP1/2-depleted conditions. We show that NIK stabilization, obtained by activation of the non-death TNFRs Fn14 or LTbetaR, is required for TNFalpha-mediated apoptosis. These apoptotic stimuli trigger the depletion of c-IAP1/2, the phosphorylation of RIP1 and the RIP1 kinase-dependent assembly of the RIP1/FADD/caspase-8 complex. In the absence of NIK, the phosphorylation of RIP1 and the formation of RIP1/FADD/caspase-8 complex are compromised while c-IAP1/2 depletion is unaffected. In vitro kinase assays revealed that recombinant RIP1 is a bona fide substrate of NIK. In vivo, we demonstrated the requirement of NIK pro-death function, but not the processing of its substrate p100 into p52, in a mouse model of TNFR1/LTbetaR-induced thymus involution. In addition, we also highlight a role for NIK in hepatocyte apoptosis in a mouse model of virus-induced TNFR1/RIP1-dependent liver damage. We conclude that NIK not only contributes to lymphoid organogenesis, inflammation and cell survival but also to TNFR1/RIP1-dependent cell death independently of the alternative NF-kappaB pathway. |