Deeper proteome sequencing is required for the global discovery of protein isoforms. Using six different human cell lines, six proteases, deep fractionation and three tandem mass spectrometry fragmentation methods, we identify a million unique peptides from 17,717 protein groups. Direct comparison with RNA expression data provides evidence for the translation of most nonsynonymous variants. This dataset represents a resource for proteoform discovery and provides direct evidence that most frame-preserving alternatively spliced isoforms are translated.
Read the article: Global Detection of Human Variants and Isoforms by Deep Proteome Sequencing