Related Experiment Video
Updated: May 27, 2026
07:35
Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess
Published on: June 1, 2022
Mitochondrial permeability transition pore and calcium handling
Renee Wong1, Charles Steenbergen, Elizabeth Murphy
1Cardiac Physiology Section, Systems Biology Center, NHLBI, NIH, Bethesda, MD 20892, USA.
Methods in Molecular Biology (Clifton, N.J.)
|November 8, 2011
Summary
The mitochondrial permeability transition (MPT) pore opening causes heart cell death during ischemia-reperfusion injury. Inhibiting the MPT pore reduces this cardiac damage.
Area of Science:
- Cardiovascular Science
- Cell Biology
- Mitochondrial Biology
Background:
- Mitochondrial permeability transition (MPT) pore opening in the inner mitochondrial membrane is a key factor in heart cell death following ischemia-reperfusion injury.
- Inhibitors of MPT pore opening have demonstrated efficacy in reducing cardiac damage.
- Many cardioprotective strategies function by mitigating MPT pore opening triggers like calcium overload or reactive oxygen species, or by directly inhibiting the pore.
Purpose of the Study:
- To review critical aspects of mitochondrial permeability transition (MPT) pore research.
- To present methodologies for quantifying MPT pore opening in isolated mitochondria.
Main Methods:
- Focus on key issues in the study of the MPT.
- Provides methods for measuring MPT opening in isolated mitochondria.
Main Results:
- MPT pore opening is a primary mediator of cell death in cardiac ischemia-reperfusion injury.
- MPT inhibitors reduce cardiac ischemia-reperfusion injury.
- Cardioprotective strategies often target MPT pore triggers or the pore itself.
Conclusions:
- Understanding and inhibiting the MPT pore is crucial for mitigating cardiac ischemia-reperfusion injury.
- Accurate measurement of MPT opening is essential for studying its role and developing therapies.
Related Concept Videos
01:28The Inner Mitochondrial Membrane
The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria. In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
01:45Mitochondrial Membranes
A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
01:45Mitochondrial Membranes
A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
01:34Protein Transport into the Inner Mitochondrial Membrane
Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Transport of mitochondrial precursors across the TIM23 channel is driven by...
01:19Translocation of Proteins into the Mitochondria
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
01:37Energy to Drive Translocation
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...