Degradation of mRNA on the membrane of endoplasmic reticulum

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07450
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Osaka Prefecture University
• Principal Investigator: Koizumi Nozomu 大阪府立大学, 生命環境科学研究科, 教授 (20252835)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 小胞体ストレス応答 / 細胞質スプライシング / 小胞体シャペロン / RNA分解 / シロイヌナズナ

Outline of Final Research Achievements

It was shown that the ER stress response occurs in a basal land plant, liverwort. Both of IRE1-mediated cytoplasmic splicing and RIDD were observed as well as in Arabidopsis.It was revealed that an amino acid sequence (ORF2) appeared in bZIP60 after cytoplasmic splicing by IRE1 increases the transcriptional activity of the ER chaperone BiP3 promoter by about ten-fold. Arabidopsis expressing a mutated seed storage protein was produced. In the seeds of this plant, the accumulation of seed storage protein was reduced, and BiP3 expression, which was not normally expressed in seeds, was observed. In other words, we succeeded to produce a plant in which the ER stress response constitutively occurs in seeds.

Free Research Field

応用細胞分子生物学

Academic Significance and Societal Importance of the Research Achievements

植物では小胞体ストレス応答の分子機構、生理的役割について不明な点が少なくない。真核生物で最も古いストレスセンサーであるIRE1が介在する小胞体ストレス応答の分子メカニズムがシロイヌナズナと同様、基部陸上であるゼニゴケでも見られることを明らかにした。植物の小胞体ストレス応答の分子メカニズムの理解が進むと考えられる。
変異型の種子貯蔵タンパク質12Sアルブミンを発現するシロイヌナズナを作出したところ種子において小胞体ストレス応答が観察された。IRE1遺伝子破壊株でこの変異型12Sアルブミンを発現するシロイヌナズナを作出することで小胞体ストレス応答の生理的役割の理解が進むと期待できる。