DJ-1 was shown to prevent metabolite and protein damage caused by a glycolytic metabolite. This metabolite has been suggested to be cyclic 3-phosphoglycerate (or cyclic 3-phosphoglyceric anhydride). Catalytic efficiency of DJ-1 as a hydrolase of cyclic 3-phosphoglyceric anhydride is 10,000 times higher than other reported enzymatic activities of DJ-1. thus functioning as a redox-sensitive chaperone and as a sensor for
oxidative stress. Accordingly, DJ-1 apparently protects neurons against oxidative stress and cell death.
Pyrroloquinoline quinone (PQQ) has been shown to reduce the self-oxidation of the DJ-1 protein, an early step in the onset of some forms of
Parkinson's disease. Functional DJ-1 protein has been shown to bind metals and protect against metal-induced cytotoxicity from
copper and
mercury. DJ-1/
PARK7 and its bacterial homologs: Hsp31, YhbO, and YajL can repair
methylglyoxal and
glyoxal glycated nucleotides.
Guanine, either in the form of a free nucleotide or as a nucleotide incorporated into
nucleic acid (
DNA or
RNA), if glycated, can be repaired by DJ-1/
PARK7.
DNA repair DJ-1 is a
DNA damage response protein that is recruited to sites of DNA damage where it participates in the
repair of DNA double-strand breaks through the processes of
non-homologous end joining and
homologous recombination. Evidence for a linkage between DNA damage and
Parkinson's disease has been reported for decades. Recently evidence has been presented that defective DNA repair is linked specifically to DJ-1 mutation, and thus DJ-1 mutation likely contributes to Parkinson's disease pathogenesis. == Clinical significance ==