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Strategies for Tracking Anastasis, A Cell Survival Phenomenon that Reverses Apoptosis
Published on: February 16, 2015
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Granzyme a, a stealth killer in the mitochondrion
Safa Lucken-Ardjomande1, Jean-Claude Martinou
1Department of Cell Biology, University of Geneva, 30 quai Ernest-Ansermet, Geneva CH-1211, Switzerland.
Cell
|May 20, 2008
Summary
Killer lymphocytes induce cell death using granzyme A (GzmA), a serine protease. GzmA enters mitochondria, cleaves a key enzyme, and triggers reactive oxygen species production, causing cell death.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Killer lymphocytes induce apoptosis via caspase-dependent and -independent pathways.
- Granzyme A (GzmA) is a serine protease implicated in caspase-independent cell death.
- The precise mechanism and cellular targets of GzmA in this process remain under investigation.
Purpose of the Study:
- To elucidate the mitochondrial pathway of granzyme A-mediated cell death.
- To identify the specific mitochondrial targets of GzmA.
- To investigate the role of reactive oxygen species in GzmA-induced cytotoxicity.
Main Methods:
- Mitochondrial localization studies of GzmA.
- Biochemical assays to identify GzmA cleavage substrates.
- Analysis of reactive oxygen species production in response to GzmA.
Main Results:
- Granzyme A (GzmA) was shown to enter the mitochondrial matrix.
- GzmA does not disrupt normal mitochondrial function upon entry.
- GzmA cleaves NDUFS3, a component of the electron transport chain.
- Cleavage of NDUFS3 leads to the production of reactive oxygen species.
- This process ultimately results in caspase-independent cell death.
Conclusions:
- Granzyme A utilizes a novel mitochondrial pathway to induce cell death.
- NDUFS3 is a critical target of GzmA within the mitochondria.
- Mitochondrial reactive oxygen species generation is a key event in GzmA-mediated cytotoxicity.
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