Degradation of old tRNA and metabolisim of modified nucleotides

• Project/Area Number: 26650009
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Molecular biology
• Research Institution: University of Hyogo
• Principal Investigator: Yoshihisa Tohru 兵庫県立大学, 生命理学研究科, 教授 (60212312)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2014: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
• Keywords: tRNA / 分解 / 非対称分裂 / ヌクレオチド修飾 / 品質管理

Outline of Final Research Achievements

I picked up tRNA, a long-lived class of RNAs, to examine whether eukaryotic cells performing asymmetric cell division deliver 'wounded' tRNA molecules asymmetrically like aggregated proteins, and how modified nucleotides derived from degraded tRNA are processed, and tried to establish experimental systems in yeast. I found that 'old' yeast cells from the view of the replicative life span do not show significant difference from young cells in their tRNA localization. I also isolated temperature-sensitive tRNA mutants that lead transient increase of modified nucleotides in amount by degradation of the tRNA molecules and allow analysis of dynamics of the modified nucleotides. Finally, I analyzed molecular mechanism of nuclear import of tRNA, which strongly affects intracellular localization of tRNA, and found that one of the yeast cytosolic Hsp70s, Ssa2p, is a transport carrier of tRNA in the nuclear import.

Research Products

• [Journal Article] Motion analysis and ultrastructural study of a colonial diatom, Bacillaria paxillifer. (2016)
  • Author(s): Yamaoka, N., Suetomo, Y., Yoshihisa, T., and Sonobe, S.
  • Journal Title: Microscopy Volume: 65 Issue: 3 Pages: 211-221
  • DOI: 10.1093/jmicro/dfv375
  • Peer Reviewed
• [Journal Article] Cytosolic Hsp70 and co-chaperones constitute a novel system for tRNA import into the nucleus. (2015)
  • Author(s): Takano, A., Kajita, T., Mochizuki, M., Endo, T., and Yoshihisa, T.
  • Journal Title: eLife Volume: 4
  • DOI: 10.7554/elife.04659
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Nucleocytoplasmic shuttling of tRNAs and implication of the cytosolic Hsp70 system in tRNA import (2015)
  • Author(s): Yoshihisa, T.
  • Journal Title: Nucleus Volume: 6 Issue: 5 Pages: 339-343
  • DOI: 10.1080/19491034.2015.1082696
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] The tRNA splicing endonuclease complex cleaves the mitochondria-localized CBP1 mRNA. (2015)
  • Author(s): Tsuboi, T., Yamazaki, R., Nobuta, R., Ikecuhi, K., Makino, S., Ohtaki, Y., Suzuki, Y., Yoshihisa, T., Trotta, C., and Inada, T.
  • Journal Title: Journal of Biological Chemistry Volume: 290 Issue: 26 Pages: 16021-16030
  • DOI: 10.1074/jbc.m114.634592
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Handling tRNA introns, archaeal way and eukaryotic way. (2014)
  • Author(s): Tohru Yoshihisa
  • Journal Title: Frontiers in Genetics Volume: 5
  • DOI: 10.3389/fgene.2014.00213
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] A novel import route for an N-anchor mitochondrial outer membrane protein aided by the TIM23 complex (2014)
  • Author(s): Song J, Tamura Y, Yoshihisa T, Endo T
  • Journal Title: EMBO Rep. Volume: (in press) Pages: 670-677
  • DOI: 10.1002/embr.201338142
  • Peer Reviewed / Open Access
• [Presentation] 出芽酵母の主要な細胞質Hsp70であるSsa2pは、tRNAの核内輸送体として働く。 (2015)
  • Author(s): 髙野 晃、梶田 拓弥、望月 誠、遠藤 斗志也、吉久 徹
  • Organizer: 日本生化学会・日本分子生物学会合同大会
  • Place of Presentation: 神戸ポートアイランド（神戸市）
  • Year and Date: 2015-12-01
• [Presentation] 翻訳共役型タンパク質膜透過における翻訳後膜透過因子Sec71及びSec72の寄与 (2015)
  • Author(s): 姜公秀、吉久徹、阪口雅朗
  • Organizer: 日本生化学会・日本分子生物学会合同大会
  • Place of Presentation: 神戸ポートアイランド（神戸市）
  • Year and Date: 2015-12-01
• [Presentation] Analysis of outer membrane insertion mechanism of yeast mitochondrial protein (2015)
  • Author(s): Jiyao Song、田村康、吉久徹、遠藤斗志也
  • Organizer: 日本生化学会・日本分子生物学会合同大会
  • Place of Presentation: 神戸ポートアイランド（神戸市）
  • Year and Date: 2015-12-01
• [Presentation] 酵母HAC1 mRNAの特異な翻訳制御とRNA品質管理回避 (2015)
  • Author(s): 吉久徹、小林小夏、佐藤大典、稲田利文、遠藤斗志也
  • Organizer: 日本細胞生物学会
  • Place of Presentation: タワーホール船堀（東京都江戸川区）
  • Year and Date: 2015-06-30
• [Presentation] ケイソウの滑走運動 (2015)
  • Author(s): 山岡望海、末友靖隆、吉久徹、園部誠司
  • Organizer: 日本細胞生物学会
  • Place of Presentation: タワーホール船堀（東京都江戸川区）
  • Year and Date: 2015-06-30
• [Presentation] 翻訳共役型タンパク質膜透過における翻訳後膜透過因子Sec71及びSec72の寄与 (2015)
  • Author(s): 姜公秀、吉久徹、阪口雅朗
  • Organizer: 日本細胞生物学会
  • Place of Presentation: タワーホール船堀（東京都江戸川区）
  • Year and Date: 2015-06-30
• [Presentation] tRNAの成熟化と細胞内動態 (2014)
  • Author(s): 吉久徹
  • Organizer: さきがけ「RNAと生体機能」第３回懇話会
  • Place of Presentation: ラフォーレ倶楽部伊東温泉（静岡県伊東市）
  • Year and Date: 2014-10-25 – 2014-10-26
• [Presentation] A novel import route for an N-anchor mitochondrial outer membrane protein aided by the TIM23 complex. (2014)
  • Author(s): Jiyao Song, Tamura Yasushi, Yoshihisa Tohru, Endo Toshiya
  • Organizer: 日本生化学会第87回大会
  • Place of Presentation: 国立京都国際会館（京都府京都市）
  • Year and Date: 2014-10-15 – 2014-10-18
• [Presentation] 出芽酵母におけるtRNAの細胞内動態とイントロン (2014)
  • Author(s): 吉久徹
  • Organizer: 酵母研究会：第78回講演会
  • Place of Presentation: アサヒビール（株）吹田工場（大阪府吹田市）
  • Year and Date: 2014-08-07
  • Invited
• [Presentation] 私はどうやって「tRNAの一生」にたどり着いたか (2014)
  • Author(s): 吉久徹
  • Organizer: シンポジウム「分子から生命へ」
  • Place of Presentation: 京都大学（京都府京都市）
  • Year and Date: 2014-07-26