Classical swine fever virus NS5A protein activates autophagy via the PP2A-DAPK3-Beclin 1 axis
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Published:2023-12-21
Issue:12
Volume:97
Page:
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ISSN:0022-538X
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Container-title:Journal of Virology
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language:en
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Short-container-title:J Virol
Author:
Sun Jinfu12ORCID, Yu Haixiao12, Wang Yingnan12, Li Liming12, Zhu Jinqi12, Ma Ping12, Feng Zezhong12, Tu Changchun34ORCID
Affiliation:
1. College of Life and Health Sciences, Northeastern University, Shenyang, China 2. Key Laboratory of Bioresource Research and Development of Liaoning Province, Shenyang, China 3. Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China 4. Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou University, Yangzhou, China
Abstract
ABSTRACT
Classical swine fever virus nonstructural protein NS5A is essential for viral genome replication, protein translation, virus assembly, and autophagy. In the present paper, the interaction of cellular PPP2R1A, PP2Ac, and DAPK3 with NS5A has been confirmed. These interactions mediate the dissociation of PP2A from Beclin 1 and its association with DAPK3. Downregulation of DAPK3 or PPP2R1A inhibits CSFV replication. NS5A induced phosphorylation of Ser88 (PK-15 cells) or Ser90 (HEK293T cells) on Beclin 1. Knockdown of Beclin 1 inhibited NS5A-induced autophagy, indicating that NS5A induces Beclin 1-dependent autophagy. Downregulation of DAPK3, PPP2R1A, or PP2Ac by siRNA reduced Beclin 1 phosphorylation and autophagy mediated by NS5A, showing a critical role of PP2A and DAPK3 in Beclin 1 phosphorylation and autophagy triggered by NS5A.
In vitro
analysis of Beclin 1 phosphorylation revealed PP2A as being essential for DAPK3-mediated phosphorylation of Beclin 1, indicating that PP2A may dephosphorylate DAPK3 to activate its protein kinase activity, with activated DAPK3 phosphorylated Beclin 1, and then triggering autophagy. These data show for the first time that DAPK3 can be activated through dephosphorylation by PP2A. These findings reveal a novel mechanism whereby CSFV NS5A protein activates autophagy via PP2A-DAPK3-Beclin 1 axis to favor viral replication.
IMPORTANCE
Autophagy is a conserved degradation process that maintains cellular homeostasis and regulates native and adaptive immunity. Viruses have evolved diverse strategies to inhibit or activate autophagy for their benefit. The paper reveals that CSFV NS5A mediates the dissociation of PP2A from Beclin 1 and the association of PP2A with DAPK3 by interaction with PPP2R1A and DAPK3, PP2A dephosphorylates DAPK3 to activate its protein kinase activity, and activated DAPK3 phosphorylates Beclin 1 to trigger autophagy, indicating that NS5A activates autophagy via the PP2A-DAPK3-Beclin 1 axis. These data highlight a novel mechanism by which CSFV activates autophagy to favor its replication, thereby contributing to the development of antiviral strategies.
Funder
MOST | National Natural Science Foundation of China Construction Project of Liaoning Provincial Key Laboratory China
Publisher
American Society for Microbiology
Subject
Virology,Insect Science,Immunology,Microbiology
Reference35 articles.
1. Simmonds P, Becher P, Collett MS, Gould EA, Heinz FX, Meyers G, Monath T, Pletnev A, Rice CM, Stiasny K, Thiel HJ, Weiner A, Bukh J. 2011. Family Flaviviridae, p 1002–1020. In Kin AMQ, E Lefkowitz, MJ Adams (ed), Virus taxonomy. Eighth report of the international committee on taxonomy of virus. Academic Press, San Diego. 2. The Molecular Biology of Pestiviruses 3. Thiel HJ, Plagemann PGW, MoennigV. 1996. Pestiviruses, p 1059–1074. In Fields BN, Knipe DM, Howley PM (ed), Fields virology, 3rd edition. Lippincott-Raven, Philadelphia. 4. Postnatal Persistent Infection with Classical Swine Fever Virus and Its Immunological Implications 5. Autophagy Induced by the N-Terminus of the Classic Swine Fever Virus Nonstructural Protein 5A Protein Promotes Viral Replication
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