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Arabidopsis thaliana 2,3‐bisphosphoglycerate‐independent phosphoglycerate mutase 2 activity requires serine 82 phosphorylation
Author(s) -
Duminil Pauline,
Davanture Marlène,
Oury Céline,
BoexFontvieille Edouard,
Tcherkez Guillaume,
Zivy Michel,
Hodges Michael,
Glab Nathalie
Publication year - 2021
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.15395
Subject(s) - phosphopeptide , arabidopsis thaliana , arabidopsis , serine , phosphoglycerate kinase , phosphoglycerate mutase , biochemistry , phosphoproteomics , phosphofructokinase 2 , phosphorylation , chemistry , in silico , enzyme , glycolysis , biology , protein phosphorylation , mutant , gene , protein kinase a
SUMMARY Phosphoglycerate mutases (PGAMs) catalyse the reversible isomerisation of 3‐phosphoglycerate and 2‐phosphoglycerate, a step of glycolysis. PGAMs can be sub‐divided into 2,3‐bisphosphoglycerate‐dependent (dPGAM) and ‐independent (iPGAM) enzymes. In plants, phosphoglycerate isomerisation is carried out by cytosolic iPGAM. Despite its crucial role in catabolism, little is known about post‐translational modifications of plant iPGAM. In Arabidopsis thaliana , phosphoproteomics analyses have previously identified an iPGAM phosphopeptide where serine 82 is phosphorylated. Here, we show that this phosphopeptide is less abundant in dark‐adapted compared to illuminated Arabidopsis leaves. In silico comparison of iPGAM protein sequences and 3D structural modelling of At iPGAM2 based on non‐plant iPGAM enzymes suggest a role for phosphorylated serine in the catalytic reaction mechanism. This is confirmed by the activity (or the lack thereof) of mutated recombinant Arabidopsis iPGAM2 forms, affected in different steps of the reaction mechanism. We thus propose that the occurrence of the S82‐phosphopeptide reflects iPGAM2 steady‐state catalysis. Based on this assumption, the metabolic consequences of a higher iPGAM activity in illuminated versus darkened leaves are discussed.