Method Overview for Discovering ATE1 Substrates and their Arginylation Sites

Arginylation is a protein modification event in which cellular machinery recognizes a conserved N-terminal or side-chain motif and post-translationally installs an arginine residue to signal a protein for degradation. This modification affects protein function, stability, and half-life and is essential to proper functions in mammalian systems. Since its discovery in the early 1960s, scientists have struggled to broadly characterize this modification in its canonical function outside of a handful of specific cases. It is known to be an essential cellular mark, as loss of the installation enzyme is embryonically lethal. However, the discovery of the substrates regulated by this mark has been slow and has required some creativity by the scientists who have chased it. Over the course of roughly six decades, the library of substrates has consistently grown through various applications. Here, we seek to summarize all approaches that have been applied to discovering and studying arginylation.