@Article{IPB-2541, author = {White, M. D. and Klecker, M. and Hopkinson, R. J. and Weits, D. and Mueller, C. and Naumann, C. and O’Neill, R. and Wickens, J. and Yang, J. and Brooks-Bartlett, J. C. and Garman, E. F. and Grossmann, T. N. and Dissmeyer, N. and Flashman, E.}, title = {{Plant Cysteine Oxidases are Dioxygenases that Directly Enable Arginyl Transferase-Catalyzed Arginylation of N-End Rule Targets}}, year = {2016}, journal = {bioRxiv}, doi = {10.1101/069336}, abstract = {Crop yield loss due to flooding is a threat to food security. Submergence-induced hypoxia in plants results in stabilisation of group VII ETHYLENE RESPONSE FACTORS (ERF-VIIs), which aid survival under these adverse conditions. ERF-VII stability is controlled by the N-end rule pathway, which proposes that ERF-VII N-terminal cysteine oxidation in normoxia enables arginylation followed by proteasomal degradation. The PLANT CYSTEINE OXIDASEs (PCOs) have been identified as catalysts of this oxidation. ERF-VII stabilisation in hypoxia presumably arises from reduced PCO activity. We directly demonstrate that PCO dioxygenase activity produces Cys-sulfinic acid at the N-terminus of an ERF-VII peptide, which then undergoes efficient arginylation by an arginyl transferase (ATE1). This is the first molecular evidence showing N-terminal Cys-sulfinic acid formation and arginylation by N-end rule pathway components, and the first ATE1 substrate in plants. The PCOs and ATE1 may be viable intervention targets to stabilise N-end rule substrates, including ERF-VIIs to enhance submergence tolerance in agronomy.} }