Overexpression of Mitochondrial Leishmania major Ascorbate Peroxidase Enhances Tolerance to Oxidative Stress-Induced Programmed Cell Death and Protein Damage�†
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
Overexpression of Mitochondrial Leishmania major Ascorbate
Peroxidase Enhances Tolerance to Oxidative Stress-Induced
Programmed Cell Death and Protein Damage�†
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| Creator |
Dolai, Subhankar
Yadav, Rajesh K Pal, Swati Adak, Subrata |
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| Subject |
Structural Biology & Bioinformatics
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| Description |
Ascorbate peroxidase from Leishmania major (LmAPX) is one of the key enzymes for scavenging of reactive
oxygen species generated from the mitochondrial respiratory chain. We have investigated whether mitochondrial
LmAPX has any role in oxidative stress-induced apoptosis. The measurement of reduced glutathione
(GSH) and protein carbonyl contents in cellular homogenates indicates that overexpression of LmAPX
protects Leishmania cells against depletion of GSH and oxidative damage of proteins by H2O2 or camptothecin
(CPT) treatment. Confocal microscopy and fluorescence spectroscopy data have revealed that the intracellular
elevation of Ca2� attained by the LmAPX-overexpressing cells was always below that attained in control cells.
Flow cytometry assay data and confocal microscopy observation strongly suggest that LmAPX overexpression
protects cells from H2O2-induced mitochondrial membrane depolarization as well as ATP decrease. Western
blot data suggest that overexpression of LmAPX shields against H2O2- or CPT-induced cytochrome c and
endonuclease G release from mitochondria and subsequently their accumulation in the cytoplasm. Caspase
activity assay by flow cytometry shows a lower level of caspase-like protease activity in LmAPX-overexpressing
cells under apoptotic stimuli. The data on phosphatidylserine exposed on the cell surface and DNA fragmentation
results show that overexpression of LmAPX renders the Leishmania cells more resistant to apoptosis
provoked by H2O2 or CPT treatment. Taken together, these results indicate that constitutive overexpression of
LmAPX in the mitochondria of L. major prevents cells from the deleterious effects of oxidative stress, that is,
mitochondrial dysfunction and cellular death.
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| Publisher |
American Society for Microbiology
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| Date |
2009
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/158/1/EUKARYOTIC_CELL%2C8(11)%2C1721%2D1731%2C2009[8].pdf
Dolai, Subhankar and Yadav, Rajesh K and Pal, Swati and Adak, Subrata (2009) Overexpression of Mitochondrial Leishmania major Ascorbate Peroxidase Enhances Tolerance to Oxidative Stress-Induced Programmed Cell Death and Protein Damage�†. Eukaryotic Cell, 8 (11). pp. 1721-1731. |
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| Relation |
http://dx.doi.org/10.1128/EC.00198-09
http://www.eprints.iicb.res.in/158/ |
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