Abstract 1174 Mitochondrial localization of Arginyltransferase1 (ATE1) protein

Arginyltransferase1 (ATE1) is an evolutionarily conserved protein found in some bacteria and in across all eukaryotes. ATE1 plays pivotal role in catalyzing the covalent attachment of arginine amino acid to its substrate proteins and exerts either proteolytic or non-proteolytic effects. As a result, ATE1 acts as a regulatory protein in different biological processes including protein quality control, gene expression, spermatogenesis, cardiovascular development, and cell-cell adhesion etc. Dysregulated ATE1 levels have been reported in several human diseases such as cancer, neurodegeneration, ageing, and developmental disorders. Hence, it is utmost important for the cells to regulate normal ATE1 protein levels and its arginylation activity for physiological homeostasis. Recent research work has reported that ATE1 function is indispensable to maintain mitochondrial homeostasis, about 0.5% of the total ATE1 is localized inside mitochondria. However, the earlier studies warrant further investigation to comprehend ATE1 localization in the mitochondrial sub-compartments such as matrix or intermediate space (IMS). Our preliminary data indicate that ATE1 is localized inside the IMS compartment. Further, by employing state-of-the-art techniques such as compartment specific split-GFP system, immunogold labelling of mitochondria, and IMS and matrix targeted mitochondrial arginylation reporters we are currently validating ATE1 localization. Additionally, we also found that under oxidative stress conditions significantly higher levels of ATE1 are localized inside mitochondria.