Figure 3.

Glycolytic growth of ups1Δ cells is restored upon UPR activation. A, wild-type (WT) and ups1Δ cells expressing 4xUPRE-GFP grown to log phase in SCD medium were treated with 1 μg/ml tunicamycin, collected at the indicated time points, and subjected to Western blotting. Pgk1 and ponceau staining were monitored as a loading control. B, serial dilutions of WT and ups1Δ cells were spotted on SCD medium with or without tunicamycin (concentration as 0.25 or 0.5 μg/ml) and incubated at 30 °C for 2 days (n = at least 3). C, 4xUPRE-GFP expressing WT and ups1Δ cells transformed with an empty vector or a plasmid encoding Ire1 (pIRE1) were grown to log phase in SCD medium and subjected to Western blotting. D, serial dilutions of WT and ups1Δ cells transformed with an empty vector or pIRE1 were spotted on SCD medium and incubated at 30 °C for 2 days (n = at least 3). E, serial dilutions of WT, cho2Δ, opi3Δ, ups1Δ, ups1Δcho2Δ, and ups1Δopi3Δ cells were spotted on SCD medium and incubated at 30 °C for 2 days (n = at least 3). F, serial dilutions of WT, ire1Δ, hac1Δ, ups1Δ, ups1Δire1Δ, ups1Δhac1Δ cells were spotted on SCD medium with or without 0.25 μg/ml tunicamycin and incubated at 30 °C for 2 days (n = at least 3). G, serial dilutions of WT, ire1Δ, hac1Δ, ups1Δ, ups1Δhac1Δ cells transformed with an empty vector or pIRE1 were spotted on SCD medium and incubated at 30 °C for 2 days (n = 3). H, phospholipid composition in whole cell of WT and ups1Δ cells transformed with an empty vector or pIRE1. Data represent mean ± SD (n = 3). SCD, synthetic complete glucose; UPR, unfolded protein response; UPRE, UPR element.