Download MendeleyCrystal structure of caspase-11 CARD provides insights into caspase-11 activation.
Liu, M., Zhou, K., Xu, Z., Ma, H., Cao, X., Yin, X., Zeng, W., Zahid, A., Fu, S., Ni, K., Ye, X., Zhou, Y., Bai, L., Zhou, R., Jin, T.(2020) Cell Discov 6: 70-70
- PubMed: 33083005
- DOI: https://doi.org/10.1038/s41421-020-00201-w
- Primary Citation of Related Structures:
6KXG - PubMed Abstract:
Murine caspase-11 is the centerpiece of the non-canonical inflammasome pathway that can respond to intracellular LPS and induce pyroptosis. Caspase-11 contains two components, an N-terminal caspase recruitment domain (CARD) and a C-terminal catalytic domain. The aggregation of caspase-11 is thought to promote the auto-processing and activation of caspase-11. However, the activation mechanism of caspase-11 remains unclear. In this study, we purified the caspase-11 CARD fused to an MBP tag and found it tetramerizes in solution. Crystallographic analysis reveals an extensive hydrophobic interface formed by the H1-2 helix mediating homotypic CARD interactions. Importantly, mutations of the helix H1-2 hydrophobic residues abolished the tetramerization of MBP-tagged CARD in solution and failed to induce pyroptosis in cells. Our study provides the first evidence of the homotypic interaction mode for an inflammatory caspase by crystal model. This finding demonstrates that the tetramerization of the N-terminal CARD can promote releasing of the catalytic domain auto-inhibition, leading to the caspase-11 activation.
Organizational Affiliation:
Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, No.17 Lujiang Rd, Hefei, Anhui 230001 China.
