Figure 1.

Discovery of small open reading frame (smORF)-encoded membrane proteins through quantitative proteomics. (A) Overview of membrane-targeted quantitative proteomic discovery protocol. (B) MS/MS spectrum corresponding to an unannotated tryptic peptide fragment detected only in the heat shock sample is shown. Identified y-ions and b-ions are shown in red on the spectrum and indicated on the peptide sequence to which the spectrum was matched. (C) Extracted ion chromatograms (EICs) comparing peaks (shown in stick mode) corresponding to the peptide ion m/z value detected in (B) in heat shock and control conditions at the same retention time. The same y-axis scale is used in both conditions. A viewing window of 1 Da around the parent ion mass is used.