Wagner Roland N, Proell Martina, Kufer Thomas A, Schwarzenbacher Robert
Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
PLoS One. 2009;4(4):e4931. doi: 10.1371/journal.pone.0004931. Epub 2009 Apr 1.
Members of the Nod-like receptor (NLR) family recognize intracellular pathogens and recruit a variety of effector molecules, including pro-caspases and kinases, which in turn are implicated in cytokine processing and NF-kappaB activation.In order to elucidate the intricate network of NLR signaling, which is still fragmentary in molecular terms, we applied comprehensive yeast two-hybrid analysis for unbiased evaluation of physical interactions between NLRs and their adaptors (ASC, CARD8) as well as kinase RIPK2 and inflammatory caspases (C1, C2, C4, C5) under identical conditions. Our results confirmed the interaction of NOD1 and NOD2 with RIPK2, and between NLRP3 and ASC, but most importantly, our studies revealed hitherto unrecognized interactions of NOD2 with members of the NLRP subfamily. We found that NOD2 specifically and directly interacts with NLRP1, NLRP3 and NLRP12. Furthermore, we observed homodimerization of the RIPK2 CARD domains and identified residues in NOD2 critical for interaction with RIPK2.In conclusion, our work provides further evidence for the complex network of protein-protein interactions underlying NLR function.
核苷酸结合寡聚化结构域样受体（NLR）家族成员可识别细胞内病原体，并招募多种效应分子，包括前半胱天冬酶和激酶，这些效应分子继而参与细胞因子加工和核因子κB激活。为了阐明NLR信号传导的复杂网络（该网络在分子层面仍不完整），我们应用全面的酵母双杂交分析，在相同条件下对NLR与其接头分子（ASC、CARD8）、激酶RIPK2以及炎性半胱天冬酶（C1、C2、C4、C5）之间的物理相互作用进行无偏评估。我们的结果证实了NOD1和NOD2与RIPK2之间以及NLRP3与ASC之间的相互作用，但最重要的是，我们的研究揭示了NOD2与NLRP亚家族成员之间迄今未被认识的相互作用。我们发现NOD2特异性且直接地与NLRP1、NLRP3和NLRP12相互作用。此外，我们观察到RIPK2 CARD结构域的同源二聚化，并确定了NOD2中与RIPK2相互作用至关重要的残基。总之，我们的工作为NLR功能背后复杂的蛋白质-蛋白质相互作用网络提供了进一步的证据。
