How does the BCL-2 protein family regulate apoptosis?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

What happens to your body after you die? — death Learn what happens to the body after death.

The BCL-2 protein family acts as the primary regulatory framework for apoptosis, the process of programmed cell death. This family consists of at least 25 members that operate primarily on the membranes of mitochondria to determine whether a cell should survive or self-destruct.1

Regulation is managed by three contesting factions within the family:

BH-3-only proteins: These act as sensors that monitor the cell for dysfunction. They function as activators or sensitizers of the apoptotic process.1
Pro-apoptotic proteins (Bax and Bak): These proteins initiate the death process.1
Anti-apoptotic proteins (such as BCL-2 and BCL-XL): These proteins work to prevent cell death.1

The balance between these factions determines the cell's fate. When the pro-apoptotic signals from BH-3-only proteins and the activation of Bax and Bak overcome the protective influence of anti-apoptotic proteins, the cell initiates the death decision. Once this decision is confirmed, the cell proceeds to the execution phase, often involving caspase proteolytic enzymes that dismantle the cell's internal structures.1