Cysteine 203 of cyclophilin D is critical for cyclophilin D activation of the mitochondrial permeability transition pore

Tiffany T. Nguyen, Mark V. Stevens, Mark Kohr, Charles Steenbergen, Michael N. Sack, Elizabeth Murphy

Research output: Contribution to journalArticlepeer-review

127 Scopus citations


The mitochondrial permeability transition pore (mPTP) opening plays a critical role in mediating cell death during ischemia/ reperfusion (I/R) injury. Our previous studies have shown that cysteine 203 of cyclophilin D (CypD), a critical mPTP mediator, undergoes protein S-nitrosylation (SNO). To investigate the role of cysteine 203 in mPTP activation, we mutated cysteine 203 of CypD to a serine residue (C203S) and determined its effect on mPTP opening. Treatment of WT mouse embryonic fibroblasts (MEFs) with H 2O 2 resulted in an 50% loss of the mitochondrial calcein fluorescence, suggesting substantial activation of the mPTP. Consistent with the reported role of CypD in mPTP activation, CypD null (CypD -/-) MEFs exhibited significantly less mPTP opening. Addition of a nitric oxide donor, GSNO, to WT but not CypD -/- MEFs prior to H 2O 2 attenuated mPTP opening. To test whether Cys-203 is required for this protection, we infected CypD -/- MEFs with a C203S-CypD vector. Surprisingly, C203S-CypD reconstituted MEFs were resistant to mPTP opening in the presence or absence of GSNO, suggesting a crucial role for Cys-203 in mPTP activation. To determine whether mutation of C203S-CypD would altermPTP in vivo, we injected a recombinant adenovirus encoding C203S-CypD or WT CypD into CypD -/- mice via tail vein. Mitochondria isolated from livers of CypD -/- mice or mice expressing C203S-CypD were resistant to Ca 2+-induced swelling as compared with WT CypD-reconstituted mice. Our results indicate that the Cys-203 residue of CypD is necessary for redox stressinduced activation of mPTP.

Original languageEnglish (US)
Pages (from-to)40184-40192
Number of pages9
JournalJournal of Biological Chemistry
Issue number46
StatePublished - Nov 18 2011

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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