Sun Jiejie, Li Yinan, Liu Yu, Wang Lingling, Song Linsheng
Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China.
Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China.
Cell Commun Signal. 2025 Aug 26;23(1):383. doi: 10.1186/s12964-025-02389-4.
DM9 domain containing protein (DM9CP) is a recently discovered novel pattern recognition receptor (PRR) with the ability to recognize various microbes, but its role as a cytosolic PRR to track the invading microbes and trigger signaling pathway is still not clear. In the present study, a DM9CP (designated as DM9CP-6) and an intracellular regulatory molecule, 14-3-3 (designated as 14-3-3ε) were identified from oyster , which contained two tandem DM9 repeats and a 14-3-3ε domain, respectively. DM9CP-6 and 14-3-3ε were higher expressed in haemocytes, and their mRNA expression levels increased significantly after stimulation. DM9CP-6 could bind various polysaccharides (LPS, PGN, MAN, and D-mannose) and microbes (, , , , , and ) in vitro, and it was observed to be colocalized with the FITC-labeled , and in haemocytes in vivo. The pull-down, surface plasmon resonance (SPR) and Co-Immunoprecipitation (Co-IP) assays all demonstrated that 14-3-3ε was able to interact with DM9CP-6 in vitro or in vivo. After the expression of DM9CP-6 and 14-3-3ε was knocked down separately by RNAi, the nuclear translocation of Rel in haemocytes was inhibited, and the mRNA expressions of interleukin17-3 (IL17-3), IL17-6, Lysozyme and BigDef1 in haemocytes all decreased significantly after the oysters were stimulated with . The results collectively indicated that DM9CP-6 could function as an intracellular PRR to be associated with 14-3-3ε to trigger the NF-κB pathway, which eventually regulated the immune responses including the expressions of inflammatory cytokines and antimicrobial molecules in oysters.
The online version contains supplementary material available at 10.1186/s12964-025-02389-4.
含DM9结构域蛋白（DM9CP）是最近发现的一种新型模式识别受体（PRR），能够识别多种微生物，但其作为胞质PRR追踪入侵微生物并触发信号通路的作用仍不清楚。在本研究中，从牡蛎中鉴定出一种DM9CP（命名为DM9CP-6）和一种细胞内调节分子14-3-3（命名为14-3-3ε），它们分别含有两个串联的DM9重复序列和一个14-3-3ε结构域。DM9CP-6和14-3-3ε在血细胞中高表达，刺激后它们的mRNA表达水平显著增加。DM9CP-6在体外可结合多种多糖（LPS、PGN、MAN和D-甘露糖）和微生物（、、、、、和），在体内观察到它与血细胞中FITC标记的、和共定位。下拉实验、表面等离子体共振（SPR）和免疫共沉淀（Co-IP）实验均表明14-3-3ε在体外或体内能够与DM9CP-6相互作用。通过RNAi分别敲低DM9CP-6和14-3-3ε的表达后，血细胞中Rel的核转位受到抑制，在用刺激牡蛎后，血细胞中白细胞介素17-3（IL17-3）、IL17-6、溶菌酶和BigDef1的mRNA表达均显著下降。结果共同表明，DM9CP-6可作为一种细胞内PRR与14-3-3ε相关联，触发NF-κB通路，最终调节包括牡蛎中炎性细胞因子和抗菌分子表达在内的免疫反应。
在线版本包含可在10.1186/s12964-025-02389-4获取的补充材料。
