White spot syndrome virus directly activates mTORC1 signaling to facilitate its replication via polymeric immunoglobulin receptor-mediated infection in shrimp

PLoS Pathog. 2022 Sep 6;18(9):e1010808. doi: 10.1371/journal.ppat.1010808. eCollection 2022 Sep.

Abstract

Previous studies have shown that the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway has antiviral functions or is beneficial for viral replication, however, the detail mechanisms by which mTORC1 enhances viral infection remain unclear. Here, we found that proliferation of white spot syndrome virus (WSSV) was decreased after knockdown of mTor (mechanistic target of rapamycin) or injection inhibitor of mTORC1, rapamycin, in Marsupenaeus japonicus, which suggests that mTORC1 is utilized by WSSV for its replication in shrimp. Mechanistically, WSSV infects shrimp by binding to its receptor, polymeric immunoglobulin receptor (pIgR), and induces the interaction of its intracellular domain with Calmodulin. Calmodulin then promotes the activation of protein kinase B (AKT) by interaction with the pleckstrin homology (PH) domain of AKT. Activated AKT phosphorylates mTOR and results in the activation of the mTORC1 signaling pathway to promote its downstream effectors, ribosomal protein S6 kinase (S6Ks), for viral protein translation. Moreover, mTORC1 also phosphorylates eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1), which will result in the separation of 4EBP1 from eukaryotic translation initiation factor 4E (eIF4E) for the translation of viral proteins in shrimp. Our data revealed a novel pathway for WSSV proliferation in shrimp and indicated that mTORC1 may represent a potential clinical target for WSSV control in shrimp aquaculture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiviral Agents / pharmacology
  • Calmodulin / metabolism
  • Eukaryotic Initiation Factor-4E / metabolism
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptors, Polymeric Immunoglobulin* / metabolism
  • Ribosomal Protein S6 Kinases / metabolism
  • Ribosomal Protein S6 Kinases / pharmacology
  • Signal Transduction
  • Sirolimus / pharmacology
  • TOR Serine-Threonine Kinases / metabolism
  • Viral Proteins / metabolism
  • Virus Replication
  • White spot syndrome virus 1* / metabolism

Substances

  • Antiviral Agents
  • Calmodulin
  • Eukaryotic Initiation Factor-4E
  • Receptors, Polymeric Immunoglobulin
  • Viral Proteins
  • Mechanistic Target of Rapamycin Complex 1
  • Proto-Oncogene Proteins c-akt
  • Ribosomal Protein S6 Kinases
  • TOR Serine-Threonine Kinases
  • Sirolimus

Grants and funding

This work was funded by the National Natural Science Foundation of China (31930112) to JXW, and National Key Research and Development Program of China (2018YFD0900502) to JXW. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.