RIPK1 is not essential for TNFR1-induced activation of NF-κB

Abstract

On TNF binding, receptor-interacting protein kinase 1 (RIPK1) is recruited to the cytoplasmic domain of TNFR1, at which it becomes ubiquitylated and serves as a platform for recruitment and activation of NEMO/IKK1/IKK2 and TAK1/TAB2. RIPK1 is commonly thought to be required for the activation of canonical NF-B and for inhibition TNFR1-induced apoptosis. RIPK1 has, however, also been reported to be essential for TNFR1-induced apoptosis when cIAPs are depleted. To determine the role of RIPK1 in TNF/IAP antagonist-induced death, we compared wild type (WT) and RIPK1-/-mouse embryonic fibroblasts (MEFs) treated with these compounds. On being treated with TNF plus IAP antagonist, RIPK1 -/-MEFs sur..