release of matrix enzymes from mitochondria

Definition

Target type: biologicalprocess

The process in which enzymes, such as aspartate aminotransferase, are enabled to move from the mitochondrial matrix into the cytosol, as part of the apoptotic process. [GOC:mah, GOC:mtg_apoptosis, PMID:9843949]

The release of matrix enzymes from mitochondria, a critical event in apoptosis and other cellular stress responses, is a tightly regulated process involving multiple mechanisms.

**1. Mitochondrial Permeability Transition Pore (mPTP) Opening:**
* The mPTP is a large, non-selective channel formed in the inner mitochondrial membrane.
* Its opening is triggered by various stressors, including oxidative stress, calcium overload, and ATP depletion.
* mPTP opening leads to the disruption of the mitochondrial membrane potential, mitochondrial swelling, and the release of matrix enzymes into the cytosol.

**2. Outer Mitochondrial Membrane (OMM) Permeabilization:**
* The OMM can be permeabilized by pro-apoptotic proteins, such as Bax and Bak, which form oligomers and create pores in the membrane.
* This process is triggered by caspase activation and other apoptotic signaling pathways.
* Permeabilization of the OMM allows the release of intermembrane space proteins, including cytochrome c, as well as matrix enzymes.

**3. Apoptosis-Inducing Factor (AIF) Release:**
* AIF is a mitochondrial protein that promotes caspase-independent apoptosis.
* It is released from the mitochondria during apoptosis and translocates to the nucleus, where it induces DNA fragmentation.

**4. Endonuclease G Release:**
* Endonuclease G is another mitochondrial protein that contributes to DNA degradation during apoptosis.
* It is released from the mitochondria and translocates to the nucleus, where it cleaves DNA.

**5. Release of Other Matrix Enzymes:**
* Besides the key enzymes involved in apoptosis, other mitochondrial matrix enzymes, such as malate dehydrogenase, aconitase, and fumarase, can also be released into the cytosol.
* These enzymes contribute to the disruption of cellular metabolism and may further amplify apoptotic signaling.

**Overall, the release of matrix enzymes from mitochondria is a complex and multifaceted process that plays a crucial role in cellular fate. It is tightly regulated and involves the interplay of various factors, including mitochondrial membrane permeability, apoptotic signaling pathways, and the activation of specific pro-apoptotic proteins.**'
"

Proteins (1)

Compounds (2)