Pub1 is necessary for stress granule (SG) formation and regulates Sir2 expression during grape juice fermentation. A) SG formation during grape juice fermentation. A Pab1-GFP fusion was inserted in the EC1118 wild type strain and its pub1 Δ derivative and its fluorescence was observed at days 1, 4 and 7 of grape juice fermentation. B) SG formation at stationary phase in SC medium. The same strains were grown for three days in SC, the reference point for CLS experiments in laboratory conditions. C) Northern blot analysis of the SIR2 mRNA levels during grape juice fermentation for the EC1118 strain and its pub1 Δ derivative. rRNA is used as the loading control. D) Western blot of Sir2 protein in the same conditions of section C). Coomassie blue staining was used as the loading control.