Tyrosyl-tRNA synthetase has a noncanonical function in actin bundling
Biljana Ermanoska, Bob Asselbergh, Laura Morant, Maria-Luise Petrovic-Erfurth, Seyyedmohsen Hosseinibarkooie, Ricardo Leitão-Gonçalves, Leonardo Almeida-Souza, Sven Bervoets, Litao Sun, LaTasha Lee, Derek Atkinson, Akram Mokhtarzadeh Khanghahi, Ivaylo Tournev, Patrick Callaerts, Patrik Verstreken, Xiang‐Lei Yang, Brunhilde Wirth, Avital A. Rodal, Vincent Timmerman, Bruce L. Goode, Tanja A. Godenschwege, Albena Jordanova
Abstract
Dominant mutations in tyrosyl-tRNA synthetase (YARS1) and six other tRNA ligases cause Charcot-Marie-Tooth peripheral neuropathy (CMT). Loss of aminoacylation is not required for their pathogenicity, suggesting a gain-of-function disease mechanism. By an unbiased genetic screen in Drosophila, we link YARS1 dysfunction to actin cytoskeleton organization. Biochemical studies uncover yet unknown actin-bundling property of YARS1 to be enhanced by a CMT mutation, leading to actin disorganization in the Drosophila nervous system, human SH-SY5Y neuroblastoma cells, and patient-derived fibroblasts. Genetic modulation of F-actin organization improves hallmark electrophysiological and morphological features in neurons of flies expressing CMT-causing YARS1 mutations. Similar beneficial effects are observed in flies expressing a neuropathy-causing glycyl-tRNA synthetase. Hence, in this work, we show that YARS1 is an evolutionary-conserved F-actin organizer which links the actin cytoskeleton to tRNA-synthetase-induced neurodegeneration.