The intricate interactions between viruses and hosts include exploitation of host cells for viral replication by using many cellular resources, metabolites and energy. Tomato bushy stunt virus (TBSV), similar to other (+)RNA viruses, induces major changes in infected cells that lead to the formation of large replication compartments consisting of aggregated peroxisomal and ER membranes. Yet, it is not known how TBSV obtains the energy to fuel these energy-consuming processes. In the current work, the authors discovered that TBSV co-opts the glycolytic ATP-generating Pgk1 phosphoglycerate kinase to facilitate the assembly of new viral replicase complexes. The recruitment of Pgk1 into the viral replication compartment is through direct interaction with the viral replication proteins. Altogether, we provide evidence that the ATP generated locally within the replication compartment by the co-opted Pgk1 is used to fuel the ATP-requirement of the co-opted heat shock protein 70 (Hsp70) chaperone, which is essential for the assembly of new viral replicase complexes and the activation of functional viral RNA-dependent RNA polymerase. The advantage of direct recruitment of Pgk1 into the virus replication compartment could be that the virus replicase assembly does not need to intensively compete with cellular processes for access to ATP. In addition, local production of ATP within the replication compartment could greatly facilitate the efficiency of Hsp70-driven replicase assembly by providing high ATP concentration within the replication compartment.
Digital Object Identifier (DOI)
This work was supported by NSF-MCB (1517751).
Prasanth, K. Reddisiva; Chuang, Chingkai; and Nagy, Peter D., "Co-Opting ATP-Generating Glycolytic Enzyme PGK1 Phosphoglycerate Kinase Facilitates the Assembly of Viral Replicase Complexes" (2017). Plant Pathology Faculty Publications. 66.
S1 Fig. Co-purification of Pgk1 with the p33 viral replication protein.
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S2 Fig. Reduced TBSV repRNA accumulation in yeast with depleted Pgk1 level at a late time point.
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S3 Fig. Knock-down of Pgk1 level by VIGS reduces the symptoms caused by CNV.
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S4 Fig. Reduced activity of the TBSV replicase assembled in vitro in CFEs prepared from a yeast strain (GALS::PGK1) with reduced level of Pgk1 expression.
journal.ppat.1006689.s005.docx (147 kB)
S1 Text. Additional materials and methods used in this study.