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The Arabidopsis DJ-1a protein confers stress protection through cytosolic SOD activation

2010; The Company of Biologists; Volume: 123; Issue: 10 Linguagem: Inglês

10.1242/jcs.063222

1477-9137

Xiang Xu, Hong Lin, Jodi Maple‐Grødem, Benny Björkblom, Guido Alves, Jan Petter Larsen, Simon Geir Møller,

Photosynthetic Processes and Mechanisms

Mutations in the DJ-1 gene (also known as PARK7) cause inherited Parkinson's disease, which is characterized by neuronal death. Although DJ-1 is thought to be an antioxidant protein, the underlying mechanism by which loss of DJ-1 function contributes to cell death is unclear. Human DJ-1 and its Arabidopsis thaliana homologue, AtDJ-1a, are evolutionarily conserved proteins, indicating a universal function. To gain further knowledge of the molecular features associated with DJ-1 dysfunction, we have characterized AtDJ-1a. We show that AtDJ-1a levels are responsive to stress treatment and that AtDJ-1a loss of function results in accelerated cell death in aging plants. By contrast, transgenic plants with elevated AtDJ-1a levels have increased protection against environmental stress conditions, such as strong light, H2O2, methyl viologen and copper sulfate. We further identify superoxide dismutase 1 (SOD1) and glutathione peroxidase 2 (GPX2) as interaction partners of both AtDJ-1a and human DJ-1, and show that this interaction results in AtDJ-1a- and DJ-1-mediated cytosolic SOD1 activation in a copper-dependent fashion. Our data have highlighted a conserved molecular mechanism for DJ-1 and revealed a new protein player in the oxidative stress response of plants.