Laboratory of Medical Genetics, Harbin Medical University, Harbin 150081, China.
J Biol Chem. 2010 Feb 19;285(8):5347-60. doi: 10.1074/jbc.M109.076976. Epub 2009 Dec 28.
Transforming growth factor-beta-activated kinase 1 (TAK1) plays an essential role in the tumor necrosis factor alpha (TNFalpha)- and interleukin-1beta (IL-1beta)-induced IkappaB kinase (IKK)/nuclear factor-kappaB (NF-kappaB) and c-Jun N-terminal kinase (JNK)/activator protein 1 (AP-1) activation. Here we report that TNFalpha and IL-1beta induce Lys(63)-linked TAK1 polyubiquitination at the Lys(158) residue within the kinase domain. Tumor necrosis factor receptor-associated factors 2 and 6 (TRAF2 and -6) act as the ubiquitin E3 ligases to mediate Lys(63)-linked TAK1 polyubiquitination at the Lys(158) residue in vivo and in vitro. Lys(63)-linked TAK1 polyubiquitination at the Lys(158) residue is required for TAK1-mediated IKK complex recruitment. Reconstitution of TAK1-deficient mouse embryo fibroblast cells with TAK1 wild type or a TAK1 mutant containing a K158R mutation revealed the importance of this site in TNFalpha and IL-1beta-mediated IKK/NF-kappaB and JNK/AP-1 activation as well as IL-6 gene expression. Our findings demonstrate that Lys(63)-linked polyubiquitination of TAK1 at Lys(158) is essential for its own kinase activation and its ability to mediate its downstream signal transduction pathways in response to TNFalpha and IL-1beta stimulation.
转化生长因子-β激活激酶 1（TAK1）在肿瘤坏死因子-α（TNFα）和白细胞介素-1β（IL-1β）诱导的IkappaB 激酶（IKK）/核因子-κB（NF-κB）和 c-Jun N-末端激酶（JNK）/激活蛋白 1（AP-1）激活中发挥重要作用。在这里，我们报告 TNFα 和 IL-1β 在激酶结构域内的赖氨酸（158）残基上诱导 Lys（63）连接的 TAK1 多泛素化。肿瘤坏死因子受体相关因子 2 和 6（TRAF2 和 -6）作为泛素 E3 连接酶，在体内和体外介导 Lys（63）连接的 TAK1 在 Lys（158）残基上的多泛素化。TAK1 介导的 IKK 复合物募集需要 Lys（63）连接的 TAK1 在 Lys（158）残基上的多泛素化。用 TAK1 野生型或含有 K158R 突变的 TAK1 突变体重建 TAK1 缺陷型小鼠胚胎成纤维细胞，揭示了该位点在 TNFα 和 IL-1β 介导的 IKK/NF-κB 和 JNK/AP-1 激活以及 IL-6 基因表达中的重要性。我们的研究结果表明，TAK1 在 Lys（158）上的 Lys（63）连接多泛素化对于其自身激酶激活及其在 TNFα 和 IL-1β 刺激下介导其下游信号转导途径的能力至关重要。
