TRAF family proteins link PKR with NF-κB activation
TRAF family proteins link PKR with NF-κB activation
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DOI：
10.1128/mcb.24.10.4502-4512.2004
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发表时间：
2004-05-01
影响因子：
5.3
通讯作者：
Esteban, M
中科院分区：
文献类型：
--
作者：
Gil, J;García, MA;Esteban, M
双链RNA（dsRNA）依赖性蛋白激酶PKR通过IkappaB激酶（IKK）复合物激活NF-κ B，但对可能参与该途径的其他分子知之甚少。PKR序列的分析使我们能够确定两个假定的TRAF相互作用的图案。计算机模拟进一步表明了这种相互作用的可行性。在这里，我们提出了PKR和TRAF家族蛋白在体内的共定位和物理相互作用的证据，如免疫沉淀和共聚焦显微镜实验所示。这种相互作用在PKR二聚化后被诱导。最重要的是，我们表明，PKR和TRAF之间的结合是功能相关的，如观察到的情况下，在细胞中的遗传缺陷的TRAF 2和TRAF 5或表达后的TRAY显性负性分子的PKR表达的NF-κ B活性。基于序列信息和突变和计算机对接分析，我们倾向于TRAF-PKR相互作用模型，其中TRAF的C-末端结构域与PKR激酶结构域中存在的预测TRAIT相互作用基序结合。总之，我们的数据表明TRAF家族蛋白是位于PKR下游的关键组分，其在介导dsRNA依赖性蛋白激酶激活NF-κ B中具有重要作用。
The double-stranded RNA (dsRNA)-dependent protein kinase PKR activates NF-kappaB via the IkappaB kinase (IKK) complex, but little is known about additional molecules that may be involved in this pathway. Analysis of the PKR sequence enabled us to identify two putative TRAF-interacting motifs. The viability of such an interaction was further suggested by computer modeling. Here, we present evidence of the colocalization and physical interaction between PKR and TRAF family proteins in vivo, as shown by immunoprecipitation and confocal microscopy experiments. This interaction is induced upon PKR dimerization. Most importantly, we show that the binding between PKR and TRAFs is functionally relevant, as observed by the absence of NF-kappaB activity upon PKR expression in cells genetically deficient in TRAF2 and TRAF5 or after expression of TRAY dominant negative molecules. On the basis of sequence information and mutational and computer docking analyses, we favored a TRAF-PKR interaction model in which the C-terminal domain of TRAF binds to a predicted TRAIT interaction motif present in the PKR kinase domain. Altogether, our data suggest that TRAF family proteins are key components located downstream of PKR that have an important role in mediating activation of NF-kappaB by the dsRNA-dependent protein kinase.