TAK1 Lys-158 but not Lys-209 is required for IL-1β-induced Lys63-linked TAK1 polyubiquitination and IKK/NF-κB activation

The nuclear factor kappa B (NF-kappa B) transcription factor-mediated transcription is the endpoint of a series of signal transduction events that are initiated by a vast array of stimuli. Both the proteolytic and non-proteolytic functions of ubiquitination are critically important for the regulation of NF-kappa B activation. Lys63-linked polyubiquitination of TAK1 is required for IL-1 beta-induced IKK/NF-kappa B activation. However, the lysine site that mediates Lys63-linked TAK1 polyubiquitination in IL-1 beta signaling is still controversial. Here we report that TAK1 Lysine 158 but not Lysine 209 is required for IL-1 beta-induced Lys63-linked TAK1 polyubiquitination and TAK1-mediated IKK, JNK, and p38 activation. Co-overexpression of TAK1 wild-type and K209R mutant with TAB1 induced Lys63-linked TAK1 polyubiquitination and NF-kappa B activation whereas TAK1 K158R mutant failed to do so. Furthermore, IL-1 beta induces polyubiquitination of TAK1 wild-type and K209R mutant but not K158R mutant. Reconstitution of TAK1-deficient mouse embryo fibroblast cells with wild-type, K158R mutant, or K209R mutant TAK1 reveals that TAK1 Lys-158 but not Lys-209 is required for IL-1 beta-induced IKK, p38 and JNK activation. (C) 2010 Elsevier Inc. All rights reserved.