Powerhouse down: Complex II dissociation in the respiratory chain

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Medicine

Background:

• Complex II of the respiratory chain (RC) is increasingly recognized as a critical regulator of cell death.
• Mutations in Complex II subunits are implicated in cancer and neurodegenerative diseases.
• Targeted anticancer compounds affecting Complex II are under development.

Purpose of the Study:

• To review recent mechanistic insights into Complex II activation for cell death induction.
• To highlight Complex II as a potential therapeutic target for cancer treatment.

Main Methods:

• Review of recent studies on Complex II function in cell death.
• Analysis of molecular mechanisms of Complex II activation.

Main Results:

• Complex II activation for cell death involves dissociation of SDHA and SDHB subunits.
• This dissociation is triggered by pH changes or mitochondrial calcium influx.
• The intact SDHA/SDHB subcomplex generates excessive reactive oxygen species (ROS), inducing cell death.

Conclusions:

• Complex II is a crucial mediator of cell death, particularly in cancer.
• Understanding its activation mechanism provides a basis for developing novel cancer therapeutics.
• Complex II serves as a central hub for diverse cell death signaling pathways.