Proteogenomics Gets onto the Regulation of mRNA Decoding and Translation into Protein

Proteogenomics, the integrative analysis of the proteome and the genome, increasingly provides protein-level insights about the regulation of gene expression and protein translation. Armengaud et al. (Proteomics 2017, 17, 1700211) nicely illustrate this trend with the first in-depth proteomic analysis of the eukaryotic and unicellular intestinal parasite Blastocystis sp. Not only this work constitutes an important milestone toward the proteogenomics profile of this human pathogen, but also it demonstrates at the protein level the occurrence of a specific mechanism of mRNA decoding. GU-rich motifs located downstream of mRNA polyadenylation sites create termination codons that ultimately result in the synthesis of proteins with lower molecular weight than predicted from gene sequence. Thus, the scope of proteogenomics now extends to the regulation of mRNA translation into proteins, providing a proof of concept for future studies in multicellular eukaryotes such as humans and plants.