The emerging roles of protein glutathionylation in chloroplasts.
Reactive oxygen species play important roles in redox signaling mainly through a set of reversible post-translational modifications of cysteine thiol residues in proteins, including glutathionylation and dithiol/disulfide exchange. Protein glutathionylation has been extensively studied in mammals but emerging evidence suggests that it can play important roles in plants and in chloroplast in particular. This redox modification involves protein thiols and glutathione and is mainly controlled by glutaredoxins, oxidoreductases belonging to the thioredoxin superfamily. In this review, we first present the possible mechanisms of protein glutathionylation and then introduce the chloroplast systems of glutaredoxins and thioredoxins, in order to pinpoint the biochemical properties that make some glutaredoxin isoforms the master enzymes in deglutathionylation. Finally, we discuss the possible roles of glutathionylation in thiol protection, protein regulation, reactive oxygen species scavenging and redox signaling in chloroplasts, with emphasis on the crosstalk between thioredoxin- and glutaredoxin-mediated signaling pathways.
Laboratory of Molecular Plant Physiology, Department of Experimental Evolutionary Biology, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy. mirko.zaffagnini3@unibo.it
Mirko
M
Zaffagnini
Mariette
M
Bedhomme
Stéphane D
SD
Lemaire
Paolo
P
Trost
D054479:Chloroplast Thioredoxins / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000378:metabolism; D054477:Glutaredoxins / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013438:Sulfhydryl Compounds / Q000378:metabolism
D054479:Chloroplast Thioredoxins; D016166:Free Radical Scavengers; D054477:Glutaredoxins; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; D005978:Glutathione