Abstract
Bacterial virulence factors or effectors are proteins targeted into host cells to coopt or interfere with cellular proteins and pathways. Viruses often coopt the same cellular proteins and pathways to support their replication in infected cells. Therefore, we screened the Legionella pneumophila effectors to probe virus–host interactions and identify factors that modulate tomato bushy stunt virus (TBSV) replication in yeast surrogate host. Among 302 Legionella effectors tested, 28 effectors affected TBSV replication. To unravel a coopted cellular pathway in TBSV replication, the identified DrrA effector from Legionella was further exploited. We find that expression of DrrA in yeast or plants blocks TBSV replication through inhibiting the recruitment of Rab1 small GTPase and endoplasmic reticulum-derived COPII vesicles into the viral replication compartment. TBSV hijacks Rab1 and COPII vesicles to create enlarged membrane surfaces and optimal lipid composition within the viral replication compartment. To further validate our Legionella effector screen, we used the Legionella effector LepB lipid kinase to confirm the critical proviral function of PI(3)P phosphoinositide and the early endosomal compartment in TBSV replication. We demonstrate the direct inhibitory activity of LegC8 effector on TBSV replication using a cell-free replicase reconstitution assay. LegC8 inhibits the function of eEF1A, a coopted proviral host factor. Altogether, the identified bacterial effectors with anti-TBSV activity could be powerful reagents in cell biology and virus–host interaction studies. This study provides important proof of concept that bacterial effector proteins can be a useful toolbox to identify host factors and cellular pathways coopted by (+)RNA viruses.
Original language | English |
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Pages (from-to) | 21739-21747 |
Number of pages | 9 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 116 |
Issue number | 43 |
DOIs | |
State | Published - Oct 22 2019 |
Bibliographical note
Funding Information:We thank Dr. Judit Pogany for designing experiments and effector library construction for expression in yeast and for comments on the manuscript and Ms. Jannine Baker for her assistance in screening the Legionella effector library in yeast. Dr. Christopher T. Beh (Simon Fraser University) and Dr. Daniel J. Klionsky (University of Michigan) provided yeast plasmids. This work was supported by the National Science Foundation’s Division of Molecular and Cellular Biosciences (1517751) awarded to P.D.N. and NIH-NIAID (AI120113) awarded to B.D.L.
Funding Information:
ACKNOWLEDGMENTS. We thank Dr. Judit Pogany for designing experiments and effector library construction for expression in yeast and for comments on the manuscript and Ms. Jannine Baker for her assistance in screening the Legionella effector library in yeast. Dr. Christopher T. Beh (Simon Fraser University) and Dr. Daniel J. Klionsky (University of Michigan) provided yeast plasmids. This work was supported by the National Science Foundation’s Division of Molecular and Cellular Biosciences (1517751) awarded to P.D.N. and NIH-NIAID (AI120113) awarded to B.D.L.
Publisher Copyright:
© 2019 National Academy of Sciences. All rights reserved.
Keywords
- Effector
- Host factor
- Tomato bushy stunt virus
- Viral replication
- Yeast
ASJC Scopus subject areas
- General