Bcl-2 Function

- there are numerous different theories, proposed through experimentation that have postulated how these proteins cause apoptotis or prevent it

- bcl-2 is a protein that prevents cell death

- other bcl-2 proteins, the pro-apoptotic bcl-2 family members promote cell death

- one mechanism of how blc-2 family proteins cause or prevent cell death is through activating or inactivating the inner mitochondrial permeability transition pore of cells

- the inner mitochondrial permeability transition pore regulates crucial aspects of cell viability, such as Calcium, pH and voltage

- release of cytochrome c into the cytosol activates pro-apoptotic enzymes, the caspases

- cytochrome c is a heme protein found in the inner mitochondrial membrane and is essential in ATP generation and oxidative phosphorylation by being an crucial component of the electron transport chain

- caspase-9 and caspase-3 are activated by cytochrome c release into the cytosol

- caspases are cysteine-aspartic acid proteases, basically cysteine proteases

- caspases can be classified as initiator caspases or effector caspases, depending on whether they can cleave inactive pro-forms of caspases or not

- the caspase cascade occurs which leads to programmed cell death

- MAC pore effects on the outer mitochondrial membrane has also been postulated to cause caspase activation

- MAC, mitochondrial apoptosis-induced channel, is an ion channel that forms secondary to apoptotic stimuli that push the cell towards programmed cell death