BAX complex

Definition

Target type: cellularcomponent

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

The BAX complex, a pivotal player in the apoptotic pathway, is a multi-protein assembly that forms on the mitochondrial outer membrane (MOM). This intricate structure plays a critical role in initiating apoptosis, a programmed cell death process that is essential for maintaining tissue homeostasis and eliminating damaged or unwanted cells. The BAX complex is a dynamic entity, evolving through distinct stages that reflect its function.

At its core, the BAX complex consists of the pro-apoptotic BAX protein. This protein resides in the cytoplasm in an inactive state, characterized by its soluble, monomeric form. Upon receiving apoptotic stimuli, BAX undergoes a conformational change, exposing its N-terminal hydrophobic domain and translocating to the MOM. This translocation is facilitated by the interaction of BAX with other proteins, including the pro-apoptotic BH3-only proteins like BID and BIM.

Once on the MOM, BAX oligomerizes, forming large, pore-like structures. These oligomers are thought to consist of multiple BAX molecules arranged in a ring-like configuration, spanning the MOM. The formation of BAX oligomers is crucial for the complex's function, as it disrupts the integrity of the MOM, leading to the release of pro-apoptotic factors from the intermembrane space.

The BAX complex can also interact with other pro-apoptotic proteins, such as BAK, which shares structural similarities with BAX and contributes to the formation of the complex. Additionally, the BAX complex can interact with anti-apoptotic proteins, such as Bcl-2 and Bcl-xL, which can inhibit the formation of the complex and suppress apoptosis.

The cellular component of the BAX complex is therefore a highly regulated structure that plays a crucial role in the apoptotic pathway. Its formation is triggered by apoptotic stimuli, leading to the disruption of the MOM and the release of pro-apoptotic factors, ultimately culminating in cell death. The dynamic interplay of BAX with other proteins, including BH3-only proteins, BAK, and Bcl-2 family members, ensures the precise regulation of this crucial apoptotic complex.'
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Proteins (1)

Compounds (2)