炎症性卡斯帕酶-4对细胞因子分裂的结构洞察
Pascal Devant1, Ying Dong2,3, Julian Mintseris4
1Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
Nature
|November 22, 2023
概括
人类卡斯帕斯4可以通过绕过炎症体和卡斯帕斯1来切割互白素-18 (IL-18). 化EM揭示了与气体皮质D不同的酶-4细胞因子处理和基质捕获的结构机制.这影响了先天免疫研究.
科学领域:
- 免疫学
- 结构生物学
- 生物化学
背景情况:
- 炎症性卡斯帕斯对天生的免疫力至关重要,
- 传统上,常规炎症体和酶-1 已知可以分裂亲IL-1β 和亲IL-18.
- 炎症性酶介导细胞因子处理的结构基础在很大程度上仍未确定.
研究的目的:
- 调查人类卡斯巴-4在亲IL-18处理中的作用.
- 阐明-4与其基质相互作用的结构机制.
- 要了解-4如何独立于正规炎症体释放IL-18.
主要方法:
- 生物化学测试以评估卡斯帕斯-4在亲IL-18上的分裂活性.
- 低温电子显微镜 (cryo-EM) 来确定-4-pro-IL-18复合物的结构.
- 用气皮D对基质结合和裂变机制进行比较分析.
主要成果:
- 人类卡斯帕-4能有效地切割亲IL-18,类似于卡斯帕-1.
- 卡斯巴酶-4能够分离亲IL-18和气皮D,使IL-18可以在没有常规炎症体的情况下释放.
- 克里奥EM检测显示了卡斯巴-4和亲IL-18之间的两个不同的相互作用接口,包括活性位点和外位点的相互作用.
- 已发现的细胞因子基质捕获和分裂机制与gasdermin D的机制不同.
结论:
- 人类卡斯巴酶具有显著的亲IL-18处理活性,为IL-18释放提供了替代途径.
- 这些结构性见解为了解先天免疫和炎症性疾病中的caspase-4功能提供了框架.
- 这些发现挑战了酶-1在IL-18处理中的独特作用,并突出了酶-4更广泛的基质特异性.
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