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Updated: Oct 7, 2025
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Examining BCL-2 Family Function with Large Unilamellar Vesicles
Published on: October 5, 2012
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Structural basis of BAK activation in mitochondrial apoptosis initiation
Geetika Singh1,2,3, Cristina D Guibao1,2, Jayaraman Seetharaman1
1Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
Nature Communications
|January 12, 2022
Summary
The BCL-2 effector BAK protein
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- BCL-2 proteins are key regulators of apoptosis.
- The precise mechanism of BCL-2 Effector BAK activation is not fully understood.
Purpose of the Study:
- To investigate the mechanisms of BAK autoactivation and direct activation by BH3-only proteins.
- To elucidate the structural basis of BAK activation and its role in apoptosis.
Main Methods:
- In trans BAK autoactivation assays.
- Structural analysis of BAK complexes using X-ray crystallography.
- Design and utilization of high-affinity BH3 ligands.
Main Results:
- Defined BAK autoactivation as an asymmetric "BH3-in-groove" triggering mechanism.
- Identified helix α1 destabilization as a hallmark of BAK activation.
- Demonstrated that transient BH3 binding and induced structural changes are critical for BAK activation.
Conclusions:
- BH3-only proteins activate BAK through a "hit-and-run" mechanism.
- Structural changes induced by BH3 binding are more crucial for BAK activation than ligand affinity.
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