Related Experiment Video
Updated: Jun 13, 2026
Novel RNA-Binding Proteins Isolation by the RaPID Methodology
Published on: September 30, 2016
Identification and analysis of dominant negative mutants of RAIDD and PIDD
Tae-Ho Jang1, Ju Young Bae, Ok Kyoung Park
1Department of Biochemistry, School of Biotechnology, Yeungnam University, Gyeongsan, South Korea.
Abstract:
Caspases are cysteine proteases that are essential during the initiation and execution of apoptosis and inflammation. The formation of large oligomeric protein complexes is critical to the activation of caspases in apoptotic and inflammatory signaling pathways. These oligomeric protein complexes function as a platform to recruit caspases, which leads to caspase activation via a proximity-induced mechanism. One well-known oligomeric caspase-activating complex is the PIDDosome for caspase-2 activation, which is composed of 3 protein components, PIDD, RAIDD and Caspase-2. Despite the significant role that caspase-2 activated by PIDDosome plays during genotoxic stress-induced apoptosis, the oligomerization mechanism and the method by which the caspase-activating process is mediated by the formation of PIDDosome is currently not well understood. Here, we show that the assembly mechanism of the core of PIDDosome is time-dependent and salt concentration-dependent. In addition, we demonstrate that point mutations on RAIDD (R147E) and on PIDD (Y814A) exert a dominant negative effect on the formation of the PIDDosome, and that this effect cannot be applied after the PIDDosome has been formed.
Insights
The PIDDosome complex, crucial for caspase-2 activation in apoptosis, assembles in a time- and salt-dependent manner. Specific mutations prevent its formation, highlighting key aspects of this caspase-activating complex.
Area of Science:
- Molecular Biology
- Cellular Biology
- Biochemistry
Background:
- Caspases are cysteine proteases vital for apoptosis and inflammation.
- Oligomeric protein complexes, like the PIDDosome, activate caspases via proximity-induced mechanisms.
- The PIDDosome complex comprises PIDD, RAIDD, and Caspase-2, crucial for genotoxic stress-induced apoptosis.
Purpose of the Study:
- To elucidate the assembly mechanism of the PIDDosome core.
- To understand how PIDDosome formation mediates caspase-2 activation.
- To investigate the impact of specific mutations on PIDDosome assembly.
Main Methods:
- Investigated PIDDosome assembly kinetics.
- Analyzed the effect of salt concentration on complex formation.
- Utilized point mutations (RAIDD R147E, PIDD Y814A) to study dominant-negative effects.
Main Results:
- PIDDosome core assembly is dependent on time and salt concentration.
- Specific point mutations in RAIDD and PIDD inhibit PIDDosome formation.
- The inhibitory effect of mutations is observed only during, not after, PIDDosome assembly.
Conclusions:
- The formation of the PIDDosome is a regulated process influenced by environmental factors and specific protein interactions.
- Understanding PIDDosome assembly provides insights into caspase-2 regulation in apoptosis.
- Targeting PIDDosome formation could be a strategy for modulating apoptotic pathways.
