Western analysis of frame-1 truncated proteins. DownPeptide genes with predicted frame-1 truncated proteins were tested in TAP-epitope-tag expression lines (DOT1, SKN7, GCS1). Cells were grown under various conditions: normal (n), stationary (s), synthetic minimal medium with glucose (SMD), starved in synthetic minimal medium lacking nitrogen (SD-N), or heat-treated (37 °C, 15 min). Five experiments are illustrated where truncated, and full-length proteins (arrows) were detected under different conditions. A truncated protein of DOT1 was also previously reported.23 Note that both the annPeptide and downPeptide were detected by MS/MS for DOT1, but only the downPeptide was detected by MS/MS for SKN7. The downPeptide for GCS1 was only detected with one OMSSA parameter set. The detected truncated and full-length proteins ran appropriately according to MW size markers (not shown).