中华绒螯蟹Hippo信号通路在抗菌免疫中的作用机制研究

抗菌肽的表达是无脊椎动物固有免疫的关键步骤，但调控抗菌肽表达的信号通路及其作用机理还有待深入研究。Hippo通路是近年发现调控果蝇抗菌肽表达的重要信号转导途径。我们的预研结果表明中华绒螯蟹Hippo通路关键信号分子Hpo在细菌刺激后具有明显上调的磷酸化水平，Hpo沉默会导致转录共刺激因子大量进入细胞核，并引起抗菌肽表达的极显著下降、血淋巴细菌浓度的极显著上升以及中华绒螯蟹成活率的极显著下降，提示Hippo通路在中华绒螯蟹抗菌反应中的重要作用。在本项目中我们拟：1）揭示Hippo通路的活化方式；2）筛选并验证Hippo通路转录共刺激因子的结合蛋白；3）明确转录因子的作用靶基因；4）探索靶蛋白对抗菌信号通路的调控机制。该项目的顺利实施有望初步明确Hippo通路调控中华绒螯蟹抗菌反应的分子机制，并为无脊椎动物免疫信号网络的建立提供新视角和重要参考。

The expression of antimicrobial peptides is a key step in the innate immunity of invertebrates. However, the signaling pathways that regulate the expression of antimicrobial peptides and their mechanism remain unclear. Hippo pathway is an important signaling transduction process that has been found to regulate the expression of antimicrobial peptides in fruit fly recently. Our preliminary results showed that Hpo, a key signaling molecule in the Hippo pathway of Eriocheir sinensis, had a significantly upregulated phosphorylation level post bacterial stimulation, and silencing of Hpo resulted in large numbers of Yki translocated from cytoplasm to nucleus, as well as very significantly decreased expression of antimicrobial peptides, very significantly increased bacterial concentration and very significantly suppressed survival rate of Chinese mitten crab, which indicated the critical role of Hippo pathway in antimicrobial activities. In this project, we will 1) clarify how Hippo signaling was activated; 2) Screen and verify the transcription factors that bounding with nuclear factor Yki; 3) uncover the genes that targeted by transcription factors in Hippo signaling; 4) explore the mechanism that how target protein regulated antimicrobial-related signaling pathway. The successful implementation of this project is expected to clarify the molecular mechanism of Hippo pathway regulated antibacterial response in Eriocheir sinensis, and provide a new perspective and important reference for the establishment of immune signaling network of invertebrates.