Identification of protein complex containing the chromatin remodeling factor DDM1 and characterization of its targeting mechanism on transposons

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20628
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0701:Biology at molecular to cellular levels, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Osakabe Akihisa 東京大学, 大学院理学系研究科(理学部), 特任助教 (70632107)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: トランスポゾン / ペリセントロメア / ヘテロクロマチン / メチル化DNA / クロマチンリモデリング

Outline of Final Research Achievements

In the current study, I isolated and purified the protein complex containing the chromatin remodeling factor Decrease in DNA Methylation 1 (DDM1), which functions in the maintenance of repressive epigenetic marks over transposons in Arabidopsis thaliana, and identified the candidates binding to DDM1 by mass spectrometry. I obtained Arabidopsis T-DNA insertion lines and performed the genome-wide DNA methylation analyses. As a result, DNA methylation levels in most of mutant plants were not reduced as observed in ddm1 mutant plants. However, a mutant plant of one gene, of which domains are similar to the binding candidate identified in this study, showed the reduction of DNA methylation over transposons compared to wild type plants.

Free Research Field

分子生物学、生化学、遺伝学

Academic Significance and Societal Importance of the Research Achievements

トランスポゾンは動植物ゲノムの進化に重要な役割を果たす一方、その可動的な性質からゲノム恒常性維持に脅威をもたらすことが知られている。また、DDM1の哺乳類オルソログHELLS/LSHの機能喪失に伴うヘテロクロマチン中の脱メチル化がICF患者で確認されている。したがって、DDM1を含む複合体によるトランスポゾンの標的および鎮静化機構を明らかにすることで、植物のエピジェネティクス研究分野にとどまらず、動植物に共通した機構、さらにエピゲノム異常を示す疾病の分子機構の解明に結びつくことが期待される。