A-C. Overexpressed Snq2-GFP accumulates in the ER and induces UPR in ypt1-1 mutant cells. Snq2-yEGFP was overexpressed in WT and ypt1-1 mutant cells and the following effects were analyzed as described for Fig 1A-1C, respectively: increase in the level of Snq2-yEGFP protein (A), accumulation of Snq2-yEGFP in aberrant ER structures (B), 