Vps34p PI3K is an essential host factor for tombusvirus replication in yeast.

(A) Deletion of Vps34 inhibits TBSV replication in yeast. Northern blot analysis of TBSV repRNA using a 3’ end specific probe shows reduced accumulation of repRNA in vps34Δ yeast strain in comparison with the wt yeast strain. Viral proteins His6-p33 and His6-p92 were expressed from plasmids from the galactose-inducible GAL1 promoter, while DI-72(+) repRNA was expressed from the GAL10 promoter. Vps34-Flag and its two defective mutants were separately expressed from a plasmid as shown. Northern blot with 18S ribosomal RNA specific probe was used as a loading control. Bottom images: Western blot analysis of the level of His6-p33 and His6-p92 with anti-His antibody and Vps34p with anti-Flag antibody. (B) Reduced CIRV replication in vps34Δ yeast strain. CIRV proteins Strep-p36 and Strep-p95 were expressed from plasmids from the GAL1 promoter. See further details in panel A.