Professor Meng Qingguo's lab at the School of Marine Science has made significant progress in crustacean immunology research. The relevant findings have been published online in Cell Communication and Signaling under the title "Eriocheir sinensis PI3K-mediated 14-3-3ζ phosphorylation at a conserved tyrosine residue enhances ROS production to defend against Spiroplasma eriocheiris infection." The journal has an Impact Factor of 8.9 and is ranked as a Q1 TOP journal in the 2026 Emerging Sources Citation Index (Biology category). Yu Yao, a 2025 Ph.D. student at the School of Marine Science and Engineering, is the first author, and Professor Meng Qingguo is the corresponding author.
The Chinese mitten crab (Eriocheir sinensis) is an economically important species in China's aquaculture market in recent years. Trembling disease (TD), caused by Spiroplasma eriocheiris, is one of the most destructive diseases affecting this species. In this study, preliminary proteomic analysis revealed that Es14-3-3ζ protein expression was significantly downregulated during infection by the intracellular pathogen S. eriocheiris. Interfering with Es14-3-3ζ expression using RNAi technology exacerbated Spiroplasma infection and led to increased crab mortality. During the early stage of Spiroplasma infection, the phosphorylation level of Es14-3-3ζ at a conserved tyrosine residue (Tyr129) was significantly reduced. In Drosophila S2 cells, Es14-3-3ζ phosphorylated at the Tyr129 site significantly enhanced cell viability, reduced apoptosis, and decreased Spiroplasma copy numbers. PI3K, thioredoxin (TRX1), and catalase (CAT) were identified as Es14-3-3ζ-interacting proteins. Phosphorylation of Es14-3-3ζ strengthened the interactions among these proteins. Overexpression of EsPI3K significantly increased the phosphorylation level of Es14-3-3ζ, whereas RNAi-mediated knockdown of EsPI3K led to reduced phosphorylation levels. Furthermore, Es14-3-3ζ phosphorylation significantly reduced the activities of TRX1 and CAT, thereby elevating reactive oxygen species (ROS) levels. Finally, the study identified miR-2309 as a targeting silencer of Es14-3-3ζ. The study concludes that EsPI3K phosphorylates Es14-3-3ζ and enhances the interactions between Es14-3-3ζ and antioxidant proteins, leading to inactivation of these antioxidant proteins and positive regulation of ROS levels, thereby defending against S. eriocheiris infection. This study identifies for the first time a conserved 14-3-3ζ phosphorylation site and elucidates its role in the immune response against intracellular infection. This finding not only deepens the theoretical understanding of the innate immune regulatory mechanisms in invertebrates but also provides a novel molecular target for the prevention and control of trembling disease in Chinese mitten crabs.