Selective RNA degradation by autophagy

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K15063
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Molecular biology
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Makino Shiho 東京工業大学, 科学技術創成研究院, 研究員 (70791458)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: オートファジー / RNA分解 / 液胞

Outline of Final Research Achievements

The role of autophagy in the degradation of proteins and organelles is well-characterized. However, the autophagy-mediated RNA degradation in response to stress and the potential preference of such RNA degradation have not been examined. In this study, we analyzed selective mRNA and tRNA degradation by autophagy in yeast. Profiling of mRNAs delivered to the vacuole reveals that a subset of mRNAs is preferentially delivered to the vacuole by autophagy where it is subsequently degraded. mRNA delivery to the vacuole is associated with translation: genome-wide ribosome profiling revealed a high correspondence between ribosome association and targeting to the vacuole. Moreover, tRNA is also preferentially delivered to the vacuole. We found that aminoacylation of tRNA has important role in alteration of selectivity. We propose that autophagy-mediated mRNA and tRNA degradation is a previously-unappreciated function of autophagy that affords post-transcriptional regulation.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

本研究は生物の基本的な機能維持に必須なオートファジーの生理機能を、選択的なRNA分解という観点から理解する独自の試みである。液胞/リソソーム内のRNA分解酵素は出芽酵母から高等生物まで高度に保存されている。出芽酵母で得られた知見や手法を高等生物に応用させることで、選択的なRNA分解を基盤としたオートファジーの更なる理解が期待される。