regulation of calcium import into the mitochondrion

Definition

Target type: biologicalprocess

Any process that modulates the frequency, rate or extent of calcium import into the mitochondrion. [GOC:sl, PMID:24085037]

Calcium import into mitochondria is a tightly regulated process crucial for maintaining cellular homeostasis and signaling. The primary route for calcium entry into the mitochondrial matrix is through the mitochondrial calcium uniporter (MCU), a highly selective ion channel located in the inner mitochondrial membrane.

The MCU is a multi-protein complex, with MCU being the pore-forming subunit. It is regulated by several factors, including:

* **Electrochemical gradient:** The high negative potential across the inner mitochondrial membrane drives calcium influx.
* **Microenvironment:** Local calcium concentration gradients near the MCU play a significant role. The presence of other proteins, such as MICU1 and MICU2, can modulate calcium sensitivity and selectivity of the MCU.
* **Post-translational modifications:** Phosphorylation of MCU by kinases like CaMKII can enhance its activity.
* **Mitochondrial membrane potential:** A high membrane potential is required for optimal calcium uptake.
* **Other regulatory proteins:** Several other proteins, including MCUR1, EMRE, and SLC25A24, interact with MCU and influence its activity.

The influx of calcium into the mitochondrial matrix triggers a series of events, including:

* **Activation of mitochondrial enzymes:** Calcium is a critical cofactor for several key enzymes in the citric acid cycle, such as pyruvate dehydrogenase and isocitrate dehydrogenase, promoting ATP production.
* **Regulation of mitochondrial respiration:** Calcium influx can stimulate mitochondrial respiration by enhancing electron transport chain activity.
* **Induction of apoptosis:** High levels of calcium in the mitochondrial matrix can trigger the release of cytochrome c, leading to apoptosis.

In addition to the MCU, other pathways for calcium entry into mitochondria exist, including:

* **Sodium-calcium exchange (NCX):** This transporter utilizes the sodium gradient to bring calcium into the mitochondria.
* **Calcium-dependent anion channels (VDACs):** These channels can allow calcium influx in response to specific stimuli.

The regulation of calcium import into mitochondria is a complex and multifaceted process involving multiple proteins and signaling pathways. It plays a critical role in maintaining cellular function and responding to stress conditions.'
"

Proteins (1)

Compounds (21)