BAK complex

Definition

Target type: cellularcomponent

An oligomeric protein complex consisting of BAK, a member of the Bcl-2 family of anti- and proapoptotic regulators. [GOC:so, PMID:14634621]

The BAK complex is a multi-protein complex that plays a critical role in the intrinsic pathway of apoptosis, also known as the mitochondrial pathway. This pathway is triggered by various cellular stresses, such as DNA damage, growth factor deprivation, and exposure to cytotoxic agents.

The BAK complex is primarily localized to the outer mitochondrial membrane (OMM), a key site for apoptosis regulation. It is composed of several proteins:

- **BAK:** This protein is a pro-apoptotic BH3-only protein that is normally inactive. Upon apoptotic stimuli, BAK undergoes a conformational change, exposing its BH3 domain and allowing it to interact with other proteins in the complex.
- **BAX:** This protein is another pro-apoptotic BH3-only protein that can form complexes with BAK.
- **VDAC:** Voltage-dependent anion channels (VDACs) are transmembrane proteins that form pores in the OMM. They play a role in the exchange of metabolites and ions between the mitochondria and the cytosol.
- **Cytochrome c:** This protein is a heme protein located in the intermembrane space of mitochondria. Upon the activation of the BAK complex, cytochrome c is released into the cytosol, triggering a cascade of events that ultimately lead to cell death.
- **Other proteins:** The BAK complex may also contain other proteins, such as the anti-apoptotic protein Bcl-2, which can inhibit the complex's activity.

The formation of the BAK complex is a tightly regulated process. When apoptotic signals activate BAK, it undergoes a conformational change and oligomerizes, forming pores in the OMM. These pores allow for the release of cytochrome c and other pro-apoptotic molecules into the cytosol, initiating the apoptotic cascade.

The BAK complex is essential for maintaining cellular homeostasis and preventing uncontrolled cell growth. Its dysfunction can contribute to various diseases, including cancer and neurodegenerative disorders. Understanding the molecular mechanisms of BAK complex formation and function is crucial for developing new therapeutic strategies for these conditions.'
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Proteins (2)

Compounds (7)