Journal Article

A regulatory role for the redox status of the pepino mosaic virus coat protein

Aranda, Miguel A., Méndez-López, Eduardo

2023

Overview

Cysteine oxidations play important regulatory roles during animal virus infections. Despite the importance of redox modifications during plant infections, no plant virus protein has yet been shown to be regulated by cysteine oxidation. The potexvirus pepino mosaic virus (PepMV) is pandemic in tomato crops. Previously we modeled the structure of the PepMV particle and coat protein (CP) by cryo-electron microscopy and identified critical residues of the CP RNA-binding pocket that interact with the viral RNA during particle formation and viral cell-to-cell movement. The PepMV CP has a single cysteine residue (Cys127) central to its RNA binding pocket, which is highly conserved. Here we show that the Cys127Ser replacement diminishes PepMV fitness, and that PepMV CP WT is oxidized in vivo while CP C127S is not. We also show that Cys127 gets spontaneously glutathionylated in vitro , and that S-glutathionylation blocks in vitro the formation of virion-like particles (VLPs). VLPs longer than 200 nm could be formed after in planta CP C127S overexpression, while very short and dispersed VLPs were observed after CP WT overexpression. Our results strongly suggest that the CP redox status regulates CP functions via cysteine oxidation.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Analysis / Binding / Biology and Life Sciences / Capsids / Cell migration / Coat protein / Control / Cysteine / Electron microscopy / Gene expression / Genomes / Glutathione / Health aspects / Identification and classification / Infection / Leaves / Molecular weight / Oxidation / Pandemics / Physical Sciences / Plant viruses / Polyethylene glycol / Post-translational modification / Potexviruses / Proteins / Research and Analysis Methods / Residues / Ribonucleic acid / RNA / RNA polymerase / Thiols / Tomatoes / Virions / Virus diseases / Viruses