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Influenza

Researchers Uncover Mechanism of Influenza Virus Replication

Strategic Insights

— 1 min read

Scientists at the Chinese Academy of Agricultural Sciences in Harbin, People's Republic of China, have identified a key mechanism by which the influenza virus replicates and evades the host's defense system. Their study, published in PLOS Pathogens, reveals that the protein TRIM45 plays a crucial role in restricting the replication of different subtypes of influenza virus by promoting the degradation of viral PB2 protein through chaperone-mediated autophagy.

Key Takeaways:

  • The host defense system employs elaborate mechanisms to combat invading viruses, including the restriction of viral replication by proteins such as TRIM45.
  • TRIM45 restricts the replication of different subtypes of influenza virus by promoting the degradation of viral PB2 protein via chaperone-mediated autophagy.
  • The study identified a highly conserved QMRDV motif at position 602-606 of PB2, which is required for its binding with LAMP-2A or HSC70.
  • Mutations of this motif abolished the binding and degradation effect of TRIM45 on PB2, leading to increased replication and enhanced pathogenicity in mice.
  • The study revealed that TRIM45 employs its E3 ubiquitin ligase activity to mediate the K48-linked polyubiquitination and proteasomal degradation of Ca2 + -dependent cysteine protease calpain 1 (CAPN1), which prevents CAPN1-mediated cleavage of LAMP-2A.
  • The research was funded by the National Key Research and Development Program of China, National Natural Science Foundation of China, and other organizations.

Statistics:

  • 21(10) - The volume and issue number of PLOS Pathogens where the study was published.
  • 602-606 - The position of the highly conserved QMRDV motif in PB2.
  • 48 - The referenced ubiquitin chain length mediated by TRIM45 E3 ubiquitin ligase activity.
  • 10 - The number of authors listed on the research, including Li Jiang, Yihan Wang, Qibing Li, Mengya Li, Wenjun Shi, Bo Wang, Guangwen Wang, Guohua Deng, Jianzhong Shi, Guobin Tian, Xianying Zeng, Hualan Chen, and Chengjun Li.

Sources:

  • TRIM45 restricts influenza virus infection through modulating the chaperone-mediated autophagic degradation of viral PB2 protein. PLOS Pathogens, 2025;21(10).
  • Public Library Science. PLOS Pathogens. www.plospathogens.org.
  • Chinese Academy of Agricultural Sciences. State Key Laboratory for Animal Disease Control and Prevention. Harbin, People's Republic of China.
  • National Key Research and Development Program of China.
  • National Natural Science Foundation of China.
  • Natural Science Foundation of Heilongjiang Province.
  • Innovation Program of Chinese Academy of Agricultural Sciences.
  • China Agricultural Research System.

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