text: Initially written off as a non-essential process due to the ATE1 knockout in yeast, later studies have shown arginylation plays a significant role in several biological processes. The knockout of ATE1 in mice and Drosophila resulted in embryonic lethality for both species. Further studies using the mouse model to observe the effects of ATE1 knockout in the development of the organism revealed that the gene loss resulted in abnormal cardiac and craniofacial morphogenesis, impaired angiogenesis, and the ability of cells to undergo meiosis. Postnatally, ATE1 knockout resulted in weight loss, infertility, and mental retardation. Additionally, observing the effects of ATE1 deletion in Arabidopsis thaliana, a model plant organism, revealed defective shoot and leaf development, abnormal seed germination, and delayed leaf senescence. The dysfunctions resulting from the knockout of the ATE1 enzyme therefore suggest that arginylation is necessary for many physiological pathways within eukaryotes.