Examination of substrate specificity in the regulated intramembrane proteolysis

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03170
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 43020:Structural biochemistry-related
• Research Institution: Yokohama City University
• Principal Investigator: Nogi Terukazu 横浜市立大学, 生命医科学研究科, 准教授 (40379102)
• Co-Investigator(Kenkyū-buntansha): 岩崎 憲治 筑波大学, 生存ダイナミクス研究センター, 教授 (20342751)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 構造生物学 / X線結晶解析 / 電子顕微鏡解析 / 分子認識 / 膜タンパク質

Outline of Final Research Achievements

In this project, we worked on the structural analysis of E. coli site-2 protease homolog RseP and its orthologs by using x-ray crystallography and electron microscopy so as to elucidate the molecular mechanism underlying the substrate discrimination and cleavage. For an RseP orthologue from a hyperthermophilic bacterium, we designed the mutants with a grafted PA14 tag to prepare the complexes with NZ-1 Fab. Subsequently, we estimated the conformation of the PDZ tandem by performing negative stain electron microscopy on the PA14-grafted othrthologs in complex with the NZ-1 Fab. Furthermore, we succeeded in determining the x-ray crystal structures of RseP and its orthologue from a marine bacterium, which deepened our understandings of the interaction mode between RseP and substrates as well as the molecular mechanism by which RseP promotes the substrate cleavage.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

本研究ではRsePの立体構造を初めて明らかにすることに成功し、これまでのsite-2 proteaseファミリーの構造研究の停滞状況を打開することができた。膜内切断プロテアーゼは、アルツハイマー病やパーキンソン病などのヒトの疾患に関わるとともに、細菌、ウイルス、原虫など様々な病原体の感染にも関わっている。Site-2 proteaseファミリーは、特に細菌感染症と密接な関係があることから、本研究で明らかになった知見は、今後、細菌感染のメカニズムの解明や新規の治療法の開発に貢献すると期待される。