Structural analysis of NOD2, a protein involved in inflammatory bowel disease pathogenesis

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K15730
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 43020:Structural biochemistry-related
• Research Institution: The University of Tokyo
• Principal Investigator: ZHANG ZHIKUAN 東京大学, 大学院薬学系研究科(薬学部), 助教 (60866937)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 炎症性腸疾患 / 自然免疫 / NOD2 / クライオ電顕 / NLR

Outline of Final Research Achievements

The molecular mechanisms of the activation and regulation of NOD2, a pathogenic protein involved in inflammatory bowel disease, have not been elucidated. This making it difficult to understand the detailed molecular mechanisms of NOD2-related inflammatory bowel disease pathogenesis and to develop therapeutic methods targeting NOD2. This project aimed to elucidate the activation mechanism of NOD2. We established an original PEGylation method for modification of proteins in order to obtain more suitable samples for cryo-EM analysis. As a result, the application of PEGylation method to NOD2 enabled us to analyze the full-length structure of NOD2 at high resolution by cryo-EM (Structure, 2021). Besides, we also identified the interactions of NOD2 with acidic lipid membranes and a novel ligand, heparin, suggesting that they may be required for NOD2 activation. We will now analyze the complex structure of NOD2 with these interaction partners.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

炎症性腸疾患 (IBD) は指定難病の一種であり、世界中の患者数が年々増加傾向である。IBDの病因タンパク質NOD2の活性化機能の解明はIBDの分子機構の解明に繋がり、有効な治療方法の開発に重要である。本研究で開発されたPEGylation分子修飾法のクライオ電子顕微鏡への適応はNOD2を始め、様々なタンパク質の高分解能クライオ電顕解析を可能とさせる新たなサンプル調製法を提供している。また、本研究で同定したNOD2の新規相互作用分子 (酸性脂質およびヘパリン) は、NOD2の活性制御機構の解明に向ける重要な知見を提供した。