Revealing the mechanism of pri-miRNA cleavage by DROSHA and DGCR8

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K23719
• 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: Kobayashi Kan 東京大学, 大学院理学系研究科(理学部), 特任助教 (00844606)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Keywords: DROSHA / DGCR8 / pri-miRNA / LRPPRC / SLIRP / mRNA

Outline of Final Research Achievements

In this study, the pri-miRNA was successfully prepared by in vitro transcription, and Homo sapiens DROSHA and DGCR8 were expressed in HEK cell and their complex were purified by the affinity tag. However, the product yield of DROSHA-DGCR8 was not enough for cryo-EM analysis.
On the other hand, LRPPRC-SLIRP-mRNA was prepared and its data of cryo-EM were collected. However, the high resolution images were not obtained by data processing. It could be because of the high conformational flexibility of it.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

本研究でLRPPRC-SLIRP-mRNA複合体の調製に成功したことは、今後の構造機能解析によってそれがmRNAに結合して安定化する機構を解明する助けとなると考えられる。LRPPRCはアミノ酸変異によってLeigh Syndrome French Canadian variantと呼ばれる神経変性疾患を引き起こすことが知られている。この疾患ではミトコンドリアのmRNA量が減少することが知られているため、この疾患はLRPPRCがSLIRPとともにmRNAに結合してそれを安定化することができなくたったことによる可能性がある。そのため本研究の成果は医学的にも重要である。