Plant arginyltransferases (ATEs)

Abstract

Regulation of protein stability and/or degradation of misfolded and damaged proteins are essential cellular processes. A part of this regulation is mediated by the so-called N-end rule proteolytic pathway, which, in concert with the ubiquitin proteasome system (UPS), drives protein degradation depending on the N-terminal amino acid sequence. One important enzyme involved in this process is arginyl-t-RNA transferase, known as ATE. This enzyme acts post-translationally by introducing an arginine residue at the N-terminus of specific protein targets to signal degradation via the UPS. However, the function of ATEs has only recently begun to be revealed. Nonetheless, the few studies to date investigating ATE activity in plants points to the great importance of the ATE/N-end rule pathway in regulating plant signaling. Plant development, seed germination, leaf morphology and responses to gas signaling in plants are among the processes affected by the ATE/N-end rule pathway. In this review, we present some of the known biological functions of plant ATE proteins, highlighting the need for more in-depth studies on this intriguing pathway.

Post-translational Modifications of the Protein Termini

“…To date, no stable binding partners or cofactors modulating ATE1 activity have been characterized, with the exception of Liat1 that was shown to bind to ATE1 and stimulate its ability to N-terminally arginylate a model substrate in vitro ( Brower et al, 2014 ). The Ate1 gene exists in nearly all eukaryotes [with the exception of two protozoan species ( Jiang et al, 2020 )], and plants have an additional gene, Ate2 , which is believed to have arisen through gene duplication and carries a redundant biological function ( Graciet and Wellmer, 2010 ; Domitrovic et al, 2017 ). The Ate1 gene in human and mouse encodes four isoforms, generated by alternative splicing ( Rai and Kashina, 2005 ).…”