DPP9はNLRP1のC端を隔離し,炎症体の活性化を抑制する
L Robert Hollingsworth1,2,3, Humayun Sharif1,2, Andrew R Griswold4,5
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
Nature
|March 18, 2021
まとめ
ディペプチジルペプチダゼ8および9 (DPP8/DPP9) は,NLRP1炎症体のC端部と相互作用することでNLRP1炎症体の活性化を調節する. Val-boroProのような阻害剤は,この相互作用を妨害し,NLRP1の活性化と炎症反応を引き起こします.
科学分野:
- 免疫学
- 分子生物学
- 構造生物学
背景:
- 核酸結合ドメインと白素に富んだ重複ピリンドメインを含むタンパク質1 (NLRP1) は,炎症ゾームの重要なセンサーである.
- NLRP1の活性化により,カスパーゼ-1の活性化,サイトカインの成熟,および熱死が起こり,NLRP1の調節不良により,炎症性疾患が発生する.
- 細胞性ダイペプチジルペプチダゼ8および9 (DPP8/DPP9) はNLRP1と相互作用するが,NLRP1の活性化におけるその役割は不明である.
研究 の 目的:
- DPP8/DPP9によるNLRP1規制の構造的基礎を明らかにする.
- DPP8/DPP9阻害剤がNLRP1を活性化するメカニズムを理解する.
- NLRP1 C端断片 (NLRP1 CT) の炎症体活性化における役割を調査する.
主な方法:
- ヒトのNLRP1-DPP9複合体の構造を決定するための冷凍電子顕微鏡 (冷凍-EM).
- NLRP1,DPP9,およびDPP8/DPP9阻害剤の相互作用を研究する生化学分析.
- 炎症体の活性化を評価する機能的測定法
主要な成果:
- Cryo-EM構造は,DPP9,全長NLRP1,およびNLRP1CTの三元複合体を明らかにしました.
- NLRP1 CTとDPP9の結合には,NLRP1の全長が求められ,その比率による調節が示される.
- Val-boroPro (VbP) は,NLRP1 CT- DPP9の相互作用を妨害し,NLRP1 CTのN端がDPP9の活性部位に入ることを阻止し,NLRP1炎症体の活性化を促します.
結論:
- DPP9はNLRP1CTの低いレベルを消してチェックポイントとして機能します.
- NLRP1の活性化は,全長NLRP1とそのC端断片のバランスによって制御されます.
- VbPのようなDPP8/DPP9阻害剤は,NLRP1CTとの阻害相互作用を不安定化することによってNLRP1炎症体を活性化させます.
関連する概念動画
IP3/DAG Signaling Pathway
13.3K
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and...
13.3K
NF-κB-dependent Signaling Pathway
8.5K
The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
NF-κB-dependent Signaling Mechanism
The...
8.5K
Regulation of the Unfolded Protein Response
2.8K
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
2.8K
The Extrinsic Apoptotic Pathway
7.1K
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
7.1K
GPCR Desensitization
7.1K
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
7.1K
The Unfolded Protein Response
5.8K
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
5.8K


