Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Autophagy. 2024 Jun;20(6):1335-1358. doi: 10.1080/15548627.2024.2306655. Epub 2024 Feb 19.
Bacterial pore-forming toxins (PFTs) that disrupt host plasma membrane integrity (PMI) significantly contribute to the virulence of various pathogens. However, how host cells protect PMI in response to PFT perforation remains obscure. Previously, we demonstrated that the HLH-30/TFEB-dependent intrinsic cellular defense (INCED) is elicited by PFT to maintain PMI in intestinal epithelium. Yet, the molecular mechanism for the full activation of HLH-30/TFEB by PFT remains elusive. Here, we reveal that PRMT-7 (protein arginine methyltransferase-7) is indispensable to the nuclear transactivation of HLH-30 elicited by PFTs. We demonstrate that PRMT-7 participates in the methylation of HLH-30 on its RAG complex binding domain to facilitate its nuclear localization and activation. Moreover, we showed that PRMT7 is evolutionarily conserved to regulate TFEB cellular localization and repair plasma damage caused by PFTs in human intestinal cells. Together, our observations not only unveil a novel PRMT-7/PRMT7-dependent post-translational regulation of HLH-30/TFEB but also shed insight on the evolutionarily conserved mechanism of the INCED against PFT in metazoans.
细菌孔形成毒素(PFT)破坏宿主质膜完整性(PMI),对各种病原体的毒力有重要贡献。然而,宿主细胞如何在 PFT 穿孔时保护 PMI 仍不清楚。先前,我们证明了 HLH-30/TFEB 依赖性固有细胞防御(INCED)是由 PFT 引发的,以维持肠上皮细胞的 PMI。然而,PFT 完全激活 HLH-30/TFEB 的分子机制仍不清楚。在这里,我们揭示了 PRMT-7(蛋白精氨酸甲基转移酶-7)对于 PFT 引发的 HLH-30 的核转激活是必不可少的。我们证明 PRMT-7 参与 HLH-30 在其 RAG 复合物结合域上的甲基化,以促进其核定位和激活。此外,我们还表明 PRMT7 在进化上是保守的,以调节 TFEB 在人类肠道细胞中的细胞定位,并修复 PFT 引起的质膜损伤。总之,我们的观察结果不仅揭示了 HLH-30/TFEB 的一种新的 PRMT-7/PRMT7 依赖性翻译后调节,也揭示了后生动物中 INCED 对抗 PFT 的进化保守机制。