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Caspase-9 CARD : core domain interactions require a properly formed active site
Kristen L Huber, Banyuhay P Serrano, Jeanne A Hardy1
1Department of Chemistry, 104 LGRT, 710 N. Pleasant St, University of Massachusetts, Amherst, MA 01003, U.S.A. hardy@chem.umass.edu.
The Biochemical Journal
|March 4, 2018
Summary
The caspase-9 CARD domain interacts with its catalytic core, revealing a new regulatory mechanism. This interaction depends on an ordered active site, suggesting novel roles beyond apoptosome recruitment.
Area of Science:
- Biochemistry
- Molecular Biology
- Cellular Biology
Background:
- Caspase-9 is a key regulator of apoptosis, essential for programmed cell death.
- Its Caspase Activation and Recruitment Domain (CARD) facilitates interaction with the apoptosome.
- The precise function of the caspase-9 CARD outside of apoptosome interaction remains largely unexplored.
Purpose of the Study:
- To investigate the role of the caspase-9 CARD domain in regulating caspase-9 activity.
- To explore potential interactions of the CARD domain independent of the apoptosome.
- To elucidate the structural requirements for CARD-core domain interaction.
Main Methods:
- Biochemical assays to study protein-protein interactions.
- Analysis of caspase-9 structure and active site dynamics.
- Investigating the impact of active site conformation on CARD-core interaction.
Main Results:
- The caspase-9 CARD domain physically interacts with the catalytic core of caspase-9.
- This interaction is dependent on a properly formed and ordered active site.
- Disordered active site loops prevent CARD-core interaction, leading to independent domain behavior.
Conclusions:
- The caspase-9 CARD domain plays a regulatory role through intramolecular interaction with the catalytic core.
- Active site conformation is critical for this novel regulatory mechanism.
- The CARD domain may be involved in substrate recruitment or recognition in addition to apoptosome binding.
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