Coronavirus endoribonuclease antagonizes ZBP1-mediated necroptosis and delays multiple cell death pathways

• 成果类型: Article
• 署名作者: Evdokimova, Monika; Feng, Shuchen; Caobi, Allen; Moreira, Fernando R.; Jones, Dakota; Alysandratos, Konstantinos-Dionysios; Tully, Ena S.; Kotton, Darrell N.; Boyd, David F.; Banach, Bridget S.; Kirchdoerfer, Robert N.; Saeed, Mohsan; Baker, Susan C.
• 署名单位: Loyola University Chicago; Boston University; Boston University; Boston University; Boston Medical Center; Boston University; Boston University; University of Wisconsin System; University of Wisconsin Madison; University of California System; University of California Santa Cruz
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10155
• DOI: 10.1073/pnas.2419620122
• 发表日期: 2025-03-04
• 关键词: z-alpha domain; hepatitis-virus; sars-coronavirus; z-rna; responses; protein; replication; interferon; pyroptosis; apoptosis

摘要

Identifying conserved mechanisms used by viruses to delay host innate responses can reveal potential targets for antiviral therapeutics. Here, we investigated coronavirus nonstructural protein 15 (nsp15), which encodes a highly conserved endoribonuclease (EndoU). EndoU functions as an immune antagonist by limiting the accumulation of viral replication intermediates that would otherwise be sensed by the host. Despite being a promising antiviral target, it has been difficult to develop small- molecule inhibitors that target the EndoU active site. We generated nsp15 mutants of the coronaviruses severe acute respiratory syndrome coronavirus 2 (SARS- CoV-2) and mouse hepatitis virus (MHV)-A59 and identified conserved residues within the amino- terminal domain that are required for EndoU activity. Loss of EndoU activity caused the activation of host sensors, which limited viral replication in interferon- responsive cells and attenuated disease in MHV- infected mice. Using transcriptional profiling, we found that MHV EndoU mutant viruses upregulate multiple host sensors, including Z- form nucleic acid- binding protein 1 (ZBP1). We found that nsp15 mutants induced early, robust ZBP1- mediated necroptosis. EndoU mutant viruses also induced ZBP1- independent apoptosis and pyroptosis pathways, causing early, robust cell death that limits virus replication and pathogenesis. Overall, we document the importance of the amino- terminal domain for EndoU function. We also highlight the importance of nsp15/EndoU activity for evading host sensors, delaying cell death, and promoting pathogenesis.