R-catcher, a potent molecular tool to unveil the arginylome

Protein arginylation is a critical regulator of a variety of biological processes. The ability to uncover the global arginylation pattern and its associated signaling pathways would enable us to identify novel disease targets. Here, we report the development of a tool able to capture the N-terminal arginylome. This tool, termed R-catcher, is based on the ZZ domain of p62, which was previously shown to bind N-terminally arginylated proteins. Mutating the ZZ domain enhanced its binding specificity and affinity for Nt-Arg. R-catcher pulldown coupled to LC-MS/MS led to the identification of 59 known and putative arginylated proteins. Among these were a subgroup of novel ATE1-dependent arginylated ER proteins that are linked to diverse biological pathways, including cellular senescence and vesicle-mediated transport as well as diseases, such as Amyotrophic Lateral Sclerosis and Alzheimer's disease. This study presents the first molecular tool that allows the unbiased identification of arginylated proteins, thereby unlocking the arginylome and provide a new path to disease biomarker discovery.

Automated summary

Protein arginylation is a critical regulator of various biological processes, and a new tool called R-catcher has been developed to capture N-terminal arginylated proteins, leading to the identification of 59 known and putative arginylated proteins, including a subgroup of novel ATE1-dependent arginylated ER proteins linked to diverse biological pathways and diseases. This study presents the first molecular tool for unbiased identification of arginylated proteins, unlocking the arginylome and providing a new avenue for disease biomarker discovery.