BH3

BH3 or Bcl-2 homology domain 3 is a protein domain that is present in the Bcl-2 family of proteins. This family of proteins plays a crucial role in the regulation of apoptosis, or programmed cell death. The BH3 domain is a key player in the initiation of this process.

Function

The BH3 domain is responsible for the pro-apoptotic activity of the Bcl-2 family proteins. It does this by binding to and inhibiting the anti-apoptotic proteins in the family, such as Bcl-2 and Bcl-xL. This allows the pro-apoptotic proteins to initiate the process of apoptosis.

Structure

The BH3 domain is a short sequence of amino acids that forms an alpha helix. This helix is able to fit into a groove on the surface of the anti-apoptotic proteins, allowing it to bind to them and inhibit their function.

Role in Disease

Alterations in the function of the BH3 domain can lead to a variety of diseases. For example, overexpression of the anti-apoptotic proteins can lead to cancer, as the cells are able to avoid the normal process of apoptosis and continue to grow and divide. On the other hand, underexpression of these proteins can lead to neurodegenerative diseases, as the cells are unable to protect themselves from apoptosis.

See Also

• Bcl-2
• Apoptosis
• Protein domain
• Cancer
• Neurodegenerative diseases

References

BH3 Resources
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