日時：	2022年12月15日 （木）10：30～11：30
場所：	オンライン 医生物学研究所内の各研究室へは、後日開催通知と共にセミナーURLをご案内いたします。 その他のお問い合わせやご不明な点については、世話人までご連絡ください。
演者：	Dr. Reika Watanabe Staff Scientist, La Jolla Institute for Immunology, CA, USA
演題：	Visualization of intracellular Ebola virus replication by in situ cryo-electron tomography

講演要旨

The Ebola virus (EBOV) and related filoviruses cause severe hemorrhagic fever and high mortality. The nucleocapsid (NC) of EBOV lies at the virion core and contains elements required for replication in host cells. NCs assemble in inclusion bodies (replication factories) before transport to the plasma membrane from which new virions bud. Understanding the structure and conserved principles involved in NC assembly and budding are critical to develop antivirals. Since viruses are obligate intracellular parasites, we must look beyond recombinant proteins and study the structure of NC inside cells.
Focused-ion beam milling enabled cryo-electron tomography of frozen cells is an unparalleled technique to determine the structure of macromolecules in a near-native cellular environment. Using HEK-293T cells transfected with EBOV NP, VP24, and VP35, and infection with biologically-contained EBOV∆VP30, we observed NC-like structures and precursors in replication factories in the host cytoplasm. With subtomogram averaging, we obtained the first intracellular NC-like structure at 20 Å resolution. The intracellular NC structure had a different conformation than that seen in a previously published structure of NC. We observed the structural changes of the individual repeating unit of the outer NC structure and their arrangement. From these results, we propose that viral NC undergoes a structural rearrangement as it interacts with the virus matrix protein VP40 during incorporation into the virion. Our findings underscore the importance of performing structural analyses inside cells to better understand virus replication processes.

（開催言語：日本語　Language：Japanese）

 

主催：JSPS 研究拠点形成事業
Core-to-Core Program「時空間ウイルス学の国際拠点形成拠点」
共同利用・共同拠点「ウイルス・幹細胞システム医生物学共同研究拠点」
世話人：京都大学医生物学研究所　微細構造ウイルス学分野
　　　　野田　岳志 (email:t-noda@infront.kyoto-u.ac.jp)