TARS3 (also known as TARSL2) is a threonyl-tRNA synthetase-like protein that catalyzes the aminoacylation of threonine to tRNA(Thr) through a two-step reaction involving threonine activation by ATP and subsequent transfer to the tRNA acceptor end 1. The enzyme possesses an editing domain that removes incorrectly charged tRNA(Thr) at the post-transfer stage 1. Unlike the cytoplasmic threonyl-tRNA synthetase (TARS), TARS3 localizes to both the cytoplasm and nucleus, with nuclear localization mediated by a C-terminal nuclear localization sequence 1. TARS3 demonstrates aminoacylation and editing activities comparable to canonical threonyl-tRNA synthetases, though with distinct tRNA recognition and editing capacity profiles 1. TARS3 is ubiquitously expressed across mouse tissues 1 and functions as a component of the aminoacyl-tRNA synthetase core complex 2. Clinically, dysregulation of TARS3 is implicated in glioblastoma pathogenesis; miR-720-mediated downregulation of TARS3 promotes glioma migration and invasion, suggesting TARS3 may function as a tumor suppressor 3.