Analyses on vesicular traffic pathways for systemic RNAi

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H05123
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: General physiology
• Research Institution: Tokyo Women's Medical University
• Principal Investigator: Mitani Shohei 東京女子医科大学, 医学部, 教授 (90192757)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: RNAi / 小胞輸送 / 線虫

Outline of Final Research Achievements

We aim to understand the mechanisms of Systemic RNAi. We used a rsd-3 mutant strain as a parent, which is defective in RNAi, and screened for suppressor mutants. We found that a zip-type zinc transporter gene mutation results in the recovery of RNAi. A human homolog gene was able to rescue the mutant phenotype, suggesting specific and functional conservation.
We additionally screened for more RNAi mutants. We mutagenized animals and treated them with an RNAi clone, which kills wild-type animals. We isolated mutant strains which are resistant to the RNAi treatment. We identified mutant genes by whole genome sequencing. A small G regulatory protein and a nematode-specific protein are RNAi-resistant.

Free Research Field

分子細胞生理学

Academic Significance and Societal Importance of the Research Achievements

RNAiは線虫に限らず、ヒト培養細胞でもsiRNAの投与によって遺伝子機能阻害で頻繁に使われている必須技術である。また、近年は核酸医薬の基本的な手法としても広く認められている。RNAiに必須な酵素群や細胞内RNA結合タンパク質はかなり解明されたが、細胞内に取り込まれた二本鎖RNAが細胞内でどのような経路を辿って機能を発揮するか、どのような経路を辿って分解代謝されるのかについてはほとんど知見がない。本研究はその解明の根本的な因子を発見するに至っている。今後、核酸医療の最適化に有用な情報となると期待される。