RNAi screening identifies mediators of NOD2 signaling: Implications for spatial specificity of MDP recognition
RNAi screening identifies mediators of NOD2 signaling: Implications for spatial specificity of MDP recognition
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DOI：
10.1073/pnas.1209673109
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发表时间：
2012-12-26
影响因子：
11.1
通讯作者：
Rosenstiel, Philip
中科院分区：
文献类型：
--
作者：
Lipinski, Simone;Grabe, Nils;Rosenstiel, Philip
胞内核苷酸结合寡聚化结构域2（NOD 2）受体检测细菌源性胞壁酰二肽（MDP）并激活转录因子NF-κ B。在这里，我们描述了NOD 2信号的调节使用系统的RNAi屏幕。使用三次连续筛选，我们鉴定了一组20个阳性NF-κ B调节子，包括已知的通路成员RIPK 2、RELA和BIRC 4（XIAP）以及FRMPD 2（含FERM和PDZ结构域2）。FRMPD 2通过富含亮氨酸的重复序列与NOD 2相互作用，并与膜相关蛋白ERBB 2 IP形成复合物。我们证明，FRMPD 2空间组装的NOD 2信号复合物，从而限制NOD 2介导的免疫反应的极化肠上皮细胞的基底外侧隔室。我们发现，与克罗恩病相关的NOD 2富含亮氨酸重复结构域的遗传截短损害了与FRMPD 2的相互作用，并且肠道炎症导致FRMPD 2的下调。这些结果表明了上皮细胞极性如何作用于肠道NOD样受体信号传导以介导细菌识别和免疫反应控制的空间特异性的结构机制。
The intracellular nucleotide-binding oligomerization domain-2 (NOD2) receptor detects bacteria-derived muramyl dipeptide (MDP) and activates the transcription factor NF-kappa B. Here we describe the regulatome of NOD2 signaling using a systematic RNAi screen. Using three consecutive screens, we identified a set of 20 positive NF-kappa B regulators including the known pathway members RIPK2, RELA, and BIRC4 (XIAP) as well as FRMPD2 (FERM and PDZ domain-containing 2). FRMPD2 interacts with NOD2 via leucine-rich repeats and forms a complex with the membrane-associated protein ERBB2IP. We demonstrate that FRMPD2 spatially assembles the NOD2-signaling complex, hereby restricting NOD2-mediated immune responses to the basolateral compartment of polarized intestinal epithelial cells. We show that genetic truncation of the NOD2 leucine-rich repeat domain, which is associated with Crohn disease, impairs the interaction with FRMPD2, and that intestinal inflammation leads to down-regulation of FRMPD2. These results suggest a structural mechanism for how polarity of epithelial cells acts on intestinal NOD-like receptor signaling to mediate spatial specificity of bacterial recognition and control of immune responses.