We recently reported that DJ-1, generally de-
scribed as an oxidative stress response protein
(5), functions as a protein deglycase that repairs
MGO- and GO-glycated cysteines, arginines, and
lysines and releases repaired proteins with lactate
or glycolate, respectively (6). The nonenzymatic
reaction between carbonyl groups and amino
acids was discovered by Louis Camille Maillard
in 1912 (7) and involves the spontaneous reaction
of reactive carbonyls with thiol and amino groups
of proteins and nucleic acids (3). Defense against
carbonyl stress involves carbonyl scavengers [gly-
oxalases, aldoketoreductases, and efflux pumps
(3, 8)], which reduce their cellular concentration,
and fructosamine-3-kinases (9) and DJ-1, which
repair proteins having undergone glycation by
glucose and GOs, respectively.
Guanine glycation by MGO (Fig. 1A) starts with
rapid formation of an aminocarbinol (3, 4)
(Fig. 1B) that slowly transforms itself into cyclic
imidazopurinones dG-MG (3, 10–12) (Fig. 1D) and
carboxyethyl-deoxyguanosine (CEdG) (Fig. 1F).
Guanine glycation by GO leads to the formation of the imidazopurinone dG-G (Fig. 1C) and
carboxymethyl-deoxyguanosine (CMdG) (Fig. 1E).
We analyzed the glycation kinetics of guanosine
5′-triphosphate (GTP) by MGO (Fig. 1G). Addition
of MGO produced a second peak after the GTP
peak, and these changes reflected the rapid formation of aminocarbinol (peak 2). This peak then
decreased, whereas more slowly migrating peaks
increased, reflecting the conversion of the aminocarbinol into imidazopurinones (dG-MG) (peaks 3
and 4) and CEdG, as described previously (12).
Nucleotide sanitizers are major contributors to
DNA damage repair. Altered deoxyribonucleo-tides induce mutations after being incorporated
into DNA and transcriptional mutagenesis by
directing misincorporation of ribonucleotides
into RNA (2). Altered ribonucleotides are responsible for translational defects and unequal
availability of nucleoside diphosphates for ribo-nucleotide reductase (2). Deoxyguanosine triphosphate (dGTP) and GTP each migrated as a single
peak on a reversed-phase high-performance liquid
chromatography (RP-HPLC) column (Fig. 1, H
and I). After incubation with MGO, 80% of dGTP
and 46% of GTP migrated as slower-eluting peaks
containing glycated nucleotides (13). When DJ-1
was added to the initial glycation mixture (Fig.
1H) or at 2 hours after glycation onset (Fig. 1I),
DJ-1 also deglycated guanosine diphosphate
(GDP) and guanosine monophosphate (GMP)
(fig. S2, A and B), as well as GTP glycated by GO
(fig. S2C). DJ-1 deglycated dGTP and amino acids
with similar kinetics [the observed rate constant
(kobs) = 0.25 s–1] (6), suggesting that DJ-1 prin-
cipally recognizes the glycated region of its sub-
strates (fig. S2D). Hsp31 (the hchA gene product)
and YhbO efficiently deglycated GTP, whereas
YajL deglycated these compounds much less effi-
ciently (fig. S2E).
Our experiments show that DJ-1 deglycates
aminocarbinols but not imidazopurinones (Fig.
1J and fig. S1, C and D). Thus, the mechanism of
nucleotide deglycation by DJ-1 is likely similar
1Stress Molecules, Institut Jacques Monod, Université Paris
Diderot—UMR7592, 15 rue Hélène Brion, 75013 Paris,
France. 2Chimie et Biochimie Pharmacologiques et
Toxicologiques, Université Paris Descartes—Sorbonne Paris
Cité, UMR 8601, 75270 Paris, France. 3Schepens Eye
Research Institute, Massachusetts Eye and Ear Infirmary,
Department of Ophthalmology, Harvard Medical School,
Boston, MA 02114, USA. 4School of Pharmacy, Lebanese
American University, Byblos, 2038 1401 Lebanon.
5Proteomics Facility, Institut Jacques Monod, Université Paris
Diderot—UMR7592, 75013 Paris, France. 6Cellular Cycle and
Development, Institut Jacques Monod, Université Paris
Diderot—UMR7592, 75013 Paris, France. 7Institut Jacques
Monod, CNRS—Université Paris Diderot—UMR7592, 75013
Paris, France. 8Institute for Integrative Biology of the
Cell (I2BC), Commissariat à l'Energie Atomique et aux
Energies Alternatives, CNRS, Université Paris-Sud, Université
Paris-Saclay, 91198 Gif-sur-Yvette, France. 9Interfaces,
Traitements, Organisation et Dynamique des Systèmes
(ITODYS), Université Paris Diderot, UMR 7086, 15 rue
J.-A. de Baïf, 75013 Paris, France.
*Corresponding author. Email: email@example.com
†These authors contributed equally to this work.
Fig. 1. Nucleotide sanitization. (A to F) The (2ʹ-deoxy)guanosyl group
was omitted for clarity. (G) GTP was incubated with MGO and analyzed by
RP-HPLC. AU, arbitrary units. (H) dGTP incubated without or with MGO, in
the absence or presence of DJ-1. Init, initially. (I) GTP incubated without or
with MGO, and subsequently treated with DJ-1 as indicated. (J) GTP
incubated overnight with MGO, with DJ-1 present in the glycation mixture, or
DJ-1 added after GTP-MGO overnight incubation. (K) PCR performed with
dGTP, and dGTP treated with MGO, in the absence or presence of DJ-1.
Samples of 5 and 10 ml were loaded in left and right wells, respectively. All
figures are representative of three independent experiments.