Palmitoylation-mediated NLRP3 inflammasome activation in teleosts highlights evolutionary divergence in immune regulation
Li Nie, Xiangyu Wu, Wu Xiang-Yu, Zhao Zi-Yue, Fei Chen-Jie, Zhu Ting-Fang, Shao Jian-Zhong, Chen Jiong, 宁波大学海洋学院生物化学和分子生物学实验室, 浙江 宁波 315211, 中国, 宁波大学海洋学院水产生物技术教育部重点实验室, 浙江 宁波 315211, 中国, 浙江省细胞与基因工程重点实验室, 浙江大学生命科学学院, 浙江 杭州 310058, 中国
Abstract
NLRP3 inflammasome activation is pivotal for cytokine secretion and pyroptosis in response to diverse stimuli, playing a crucial role in innate immunity. While extensively studied in mammals, the regulatory mechanisms governing NLRP3 activation in non-mammalian vertebrates remain largely unexplored. Teleosts, as basal vertebrates, represent an ideal model for exploring the evolutionary trajectory of inflammasome regulation. In this study, ABE assays, confocal microscopy, and biochemical analyses were applied to systematically characterize the mechanisms underlying NLRP3 inflammasome in teleosts, using large yellow croakers (<italic>Larimichthys crocea</italic>, <italic>Lc</italic>) and zebrafish (<italic>Danio rerio</italic>, <italic>Dr</italic>) as representative models. Our findings revealed a previously unrecognized palmitoylation-dependent regulatory mechanism essential for teleost NLRP3 activation. Specifically, zDHHC18-mediated palmitoylation at a teleost-specific cysteine residue (C946 in <italic>Lc</italic>NLRP3, C1037 in <italic>Dr</italic>NLRP3) was required for the translocation of NLRP3 to the dispersed trans-Golgi network, facilitating its subsequent recruitment to the microtubule-organizing center. This membrane trafficking was crucial for inflammasome assembly and downstream inflammatory responses. These findings provide new insights into the distinct regulatory mechanisms of NLRP3 activation in teleosts, highlighting an evolutionary divergence that contributes to innate immunity adaptation in early vertebrates.