The length of the polyadenylation tails of human mitochondrial transcripts alters their stability

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K19303
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 43:Biology at molecular to cellular levels, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Matsushima Yuichi 九州大学, 医学研究院, 助教 (20571342)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Keywords: ミトコンドリア

Outline of Final Research Achievements

The functions of RNA polyadenylation are diverse. In prokaryotes, polyadenylation promotes the degradation of the RNA, whereas in eukaryotes, polyadenylation inhibits the degradation of the RNA. Human mitochondrial DNA encodes 11 mRNAs and most of which are polyadenylated during maturation. We investigated the effect of polyadenyl tail shortening on mitochondrial mRNAs. Interestingly, the shortening of polyadenyl tails produced different effects on stabilization and destabilization for each mitochondrial mRNA. These results suggest that polyadenyl-tail of mitochondrial mRNAs exhibits both prokaryotic and eukaryotic polyadenyl-tail effects in each mRNA. Further studies are needed to understand the mechanism of altered stability of the mitochondrial mRNAs by polyadenyl tails.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

真核生物の核DNAから転写されたmRNAは成熟化に伴いポリ(A)鎖が付加されその分解抑制に寄与するが、原核生物の核様体DNAから転写されたRNAでは分解時にポリ(A)鎖が一時的に付加され、それはRNAの分解促進に寄与する。興味深いことにミトコンドリアmRNAには50塩基程のポリ(A)鎖が付加されるが、このポリ(A)鎖は個々のmRNA毎に分解抑制と分解促進あるいは影響なしと全く異なる効果を持つことを示した。ヒトのミトコンドリアでは真核生物型と現各区生物型のポリ(A)鎖の機能が共存している可能性がある。