Download MendeleyStructural Insights into DD-Fold Assembly and Caspase-9 Activation by the Apaf-1 Apoptosome.
Su, T.W., Yang, C.Y., Kao, W.P., Kuo, B.J., Lin, S.M., Lin, J.Y., Lo, Y.C., Lin, S.C.(2017) Structure 25: 407-420
- PubMed: 28111022
- DOI: https://doi.org/10.1016/j.str.2016.12.019
- Primary Citation of Related Structures:
5WVC - PubMed Abstract:
Death domain (DD)-fold assemblies play a crucial role in regulating the signaling to cell survival or death. Here we report the crystal structure of the caspase recruitment domain (CARD)-CARD disk of the human apoptosome. The structure surprisingly reveals that three 1:1 Apaf-1:procaspase-9 CARD protomers form a novel helical DD-fold assembly on the heptameric wheel-like platform of the apoptosome. The small-angle X-ray scattering and multi-angle light scattering data also support that three protomers could form an oligomeric complex similar to the crystal structure. Interestingly, the quasi-equivalent environment of CARDs could generate different quaternary CARD assemblies. We also found that the type II interaction is conserved in all DD-fold complexes, whereas the type I interaction is found only in the helical DD-fold assemblies. This study provides crucial insights into the caspase activation mechanism, which is tightly controlled by a sophisticated and highly evolved CARD assembly on the apoptosome, and also enables better understanding of the intricate DD-fold assembly.
Organizational Affiliation:
Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan; Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia, Sinica, Taipei 11529, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan.
