Tissue expression of N-terminal proteoforms.

To evaluate the expression of N-terminal proteoforms (protein isoforms with different N-terminus expressed from the same gene) in healthy human tissues, we re-analyzed public proteomics data of the draft map of the human proteome developed by the Pandey group (PRIDE project PXD000561). Using ionbot search engine and a custom-build protein sequence database (composed of UniProt and Ribo-seq derived proteoforms) we confirmed that N-terminal proteoforms are not only expressed in histologically healthy human tissues, but also display tissue specificity.