A fluorescence-based reporter of Arginyltransferase 1 (ATE1)

Arginyltransferase 1 (ATE1) is an enzyme that catalyzes the transfer of arginine onto protein fragments with acidic N-termini. This is an essential step in the degradation of these fragments by the N-degron pathway of the ubiquitin proteasome system. Previous studies have shown that arginylation is required for the removal of specific fragments associated neurodegeneration, and that the loss of ATE1 activity leads to neurological problems. Interestingly, reduced ATE1 activity was also associated with fat loss and resistance to diet-induced obesity. Thus, the modulation of ATE1 holds promise for treating these increasingly common human diseases. To this end, we synthesized a cell-based reporter that employs direct fluorescence to monitor ATE1 activity. Using confocal microscopy and immunoblot analysis, we show that this reporter provides a robust readout of ATE1 activity in vivo. This reporter will be useful in screening approaches aimed to identify modulators of ATE1, which may ultimately have therapeutic potential.