Abstract
The gene encoding a superoxide dismutase (PiSOD) was cloned by suppressive subtractive hybridization from cDNA library of the ectomycorrhizal fungus, Paxillus involutus, grown under cadmium-stress conditions. The encoded protein was presumed to be localized in the peroxisomes because it contained a C-terminal peroxisomal localization peptide (SKL) and lacked an N-terminal mitochondrial transit peptide. Complementation of an Escherichia coli SOD null strain that is unable to grow in the presence of paraquat or cadmium indicated that cloned Pisod encoded a functional superoxide dismutase. Sensitivity of PiSOD activity to H2O2 but not KCN, and sequence homologies to other SODs strongly suggest that it is a manganese-containing superoxide dismutase. Monitoring PiSOD transcript, immunoreactive polypeptide and superoxide dismutase activity following cadmium stress suggests that the principal level of control is post-translational. This is, to our knowledge, the first insight in the characterization of molecular events that take place in an ectomycorrhizal fungus during exposure to heavy metals.
Original language | English (US) |
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Pages (from-to) | 3223-3232 |
Number of pages | 10 |
Journal | European Journal of Biochemistry |
Volume | 268 |
Issue number | 11 |
DOIs | |
State | Published - 2001 |
Keywords
- Cadmium
- Complementation
- Expression analysis
- Paxillus involutus
- Superoxide dismutase
ASJC Scopus subject areas
- Biochemistry