Biochemical mechanisms underlying inflammasome function

炎症小体功能的生化机制

• 批准号: RGPIN-2019-04379
• 负责人: Macdonald, Justin
• 金额: $ 2.33万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=684187
• 关键词: Biochemical; mechanisms; underlying; inflammasome; function

The innate immune system acts as the first line of defense for animals and plants in reconciling cellular injury and infection through the early detection of impending threats, and consequential triggering of pro-inflammatory responses. These immune mechanisms are mediated by an ancient family of pattern recognition receptors (PRRs). Within the greater PRR family, the NOD-like receptors-containing pyrin (NLRP) subfamily of proteins have emerged as key sensors of intracellular danger signals. Rapidly developing biological models now indicate the various NLRPs are of paramount importance in initiating inflammatory responses to cellular injury; however, critical aspects regarding the underlying biochemistry of this protein family and their signaling complexes remain unresolved. NLRP3 is the most thoroughly studied and is considered to be the prototypical inflammasome-forming member. NLRP family members contain a central NACHT domain with ATP-binding and hydrolysis properties, (sometimes referred to as the nucleotide-binding oligomerization domain or NOD), that are thought to regulate NLRP oligomerization and inflammasome activation. *** The basic biochemistry of the entire NLRP family (14 members) remains incompletely characterized. Many assumptions regarding the enzymatic activity of NLRPs and the intrinsic regulation of inflammasome formation are based primarily upon analogy with limited corroborating evidence. Further characterization of the enzymology of inflammasome activation as well as the integration of recently revealed post-translational modifications in regulating inflammatory signaling pathways will be critical for a comprehensive understanding of this protein family. In this regard, we propose that specific biochemical properties of different NLRP-NACHT domains drive distinctions in catalytic activities, which in turn can impact upon oligomerization and inflammatory signaling. Thus, a comprehensive definition of the enzymology of NLRP proteins and the role of ATP in driving inflammasome-associated signaling pathways will be critical for understanding of the innate immune process. It is clear that holistic studies of the entire NLRP family are necessary, and we will creatively advance understanding of the NLRP family as a whole and their propensity to assemble into functional inflammasomes. To address the knowledge deficit, systems for the effective production of all NLRP proteins are required, biochemical assessments of enzymatic function need to be completed, novel technologies and reagents for biological interrogations should be developed, and precise structural definitions of the catalytic NACHT domain are necessary. Our technical advances in recombinant NLRP protein production support biochemical analyses of protein and inflammasome catalytic function as well as structural biology approaches.

先天免疫系统作为动物和植物的第一道防线，通过早期检测即将发生的威胁和相应的促炎反应的触发来协调细胞损伤和感染。这些免疫机制是由一个古老的模式识别受体（PRR）家族介导的。在更大的PRR家族中，含有NOD样受体的pyrin（NLRP）蛋白亚家族已成为细胞内危险信号的关键传感器。快速发展的生物学模型表明，各种NLRP在启动细胞损伤的炎症反应中至关重要;然而，关于该蛋白质家族及其信号复合物的基础生物化学的关键方面仍未得到解决。NLRP 3是研究最彻底的，被认为是原型炎性小体形成成员。NLRP家族成员含有具有ATP结合和水解性质的中心NACHT结构域（有时称为核苷酸结合寡聚化结构域或NOD），其被认为调节NLRP寡聚化和炎性体活化。*** 整个NLRP家族（14个成员）的基本生物化学特征仍不完全。关于NLRP的酶活性和炎性小体形成的内在调节的许多假设主要基于有限的确证证据的类比。进一步表征炎性小体激活的酶学以及整合最近发现的调节炎症信号传导途径的翻译后修饰对于全面了解该蛋白质家族至关重要。在这方面，我们提出不同NLRP-NACHT结构域的特定生化特性驱动催化活性的差异，这反过来又会影响寡聚化和炎症信号传导。因此，全面定义NLRP蛋白的酶学和ATP在驱动炎性小体相关信号通路中的作用对于理解先天免疫过程至关重要。很明显，对整个NLRP家族的整体研究是必要的，我们将创造性地推进对NLRP家族整体及其组装成功能性炎性小体的倾向的理解。为了解决知识的不足，系统的有效生产的所有NLRP蛋白是必需的，生化评估的酶功能需要完成，新的技术和试剂的生物审讯应开发，和精确的结构定义的催化NACHT域是必要的。我们在重组NLRP蛋白生产方面的技术进步支持蛋白质和炎性体催化功能的生化分析以及结构生物学方法。