Abstract
Posttranslational arginylation mediated by arginyltransferase (ATE1) plays an important role in cardiovascular development, cell motility, and regulation of cytoskeleton and metabolic enzymes. This protein modification was discovered decades ago, however, the arginylation reaction and the functioning of ATE1 remained poorly understood because of the lack of good biochemical models. Here, we report the development of an in vitro arginylation system, in which ATE1 function and molecular requirements can be tested using purified recombinant ATE1 isoforms supplemented with a controlled number of components. Our results show that arginylation reaction is a self-sufficient, ATP-independent process that can affect different sites in a polypeptide and that arginyltransferases form different molecular complexes in vivo, associate with components of the translation machinery, and have distinct, partially overlapping subsets of substrates, suggesting that these enzymes play different physiological functions.
► ATE1 is ATP-independent and capable of self-arginylation ► ATE1 activity is modulated by intracellular cofactors ► ATE1 isoforms have different subsets of substrates, suggesting different functions ► ATE1 associates with the translation machinery and forms two distinct complexes in vivo
