Structural analysis of influenza virus ribonucleoprotein complexes by cryoelectron microscopy

Research Project

Project/Area Number	15K14853
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Veterinary medical science
Research Institution	Kyoto University
Principal Investigator	Noda Takeshi 京都大学, ウイルス・再生医科学研究所, 教授 (00422410)
Research Collaborator	Sugita Yukihiko 沖縄科学技術大学院大学, 博士研究員 Wolf Matthias 沖縄科学技術大学院大学, 准教授
Project Period (FY)	2015-04-01 – 2017-03-31
Project Status	Completed (Fiscal Year 2016)
Budget Amount *help	¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000) Fiscal Year 2016: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000) Fiscal Year 2015: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywords	インフルエンザウイルス / 転写・複製 / クライオ電子顕微鏡
Outline of Final Research Achievements	Each segment of influenza A virus genome (vRNA) forms a helical ribonuceoprotein complex (RNP) together with viral nucleoproteins and a polymerase. The helical RNP is responsible for transcription and replication of the vRNA, but its structure in the course of vRNA synthesis remains unknown. Here, to visualize RNP structure during transcription and replication, we examined in vitro-transcribed RNPs that were purified from influenza A virions by using cryoelectron microscopy. Control RNPs showed helical structures as reported previously. In contrast, in vitro-transcribed RNPs showed deformed structures associating with a synthesized RNA. These results suggest that RNPs would cause conformational changes during RNA synthesis.