Detection of Endogenous Protein Pyrophosphorylation Sites by a Novel Proteomics Approach
Fiedler Group, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Roessle-Str. 10, 13125, Berlin, GER
Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, GER
The diversification of proteins by posttranslational modifications is an important tool of signal transduction that allows organisms to control and modulate protein function, and thereby influences all aspects of cell biology. Over a decade ago, a unique class of highly energetic and versatile second messengers, called inositol pyrophosphates, has been found to transfer a phosphoryl group onto prephosphorylated protein sites in vitro. The resulting modification has been coined protein pyrophosphorylation. Several groups have investigated the biological role of this modification but the overall impact of pyrophosphorylation remains controversial, mainly because no direct detection method within complex cell lysate and/or in vivo samples exists to date. The current discussion in the field motivated us to design a proteomic approach using a newly developed enrichment strategy for pyrophosphorylated peptides and identified the first endogenous sites of protein pyrophosphorylation in mammalian cells and S.Cerevisiae. Ideally, this approach will help to expand our knowledge regarding the role of this modification within the signaling network.