Deubiquitylase USP10 facilitates DNA damage response.

Research Project

Project/Area Number	18K06070
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 43010:Molecular biology-related
Research Institution	Kanazawa Medical University
Principal Investigator	UTANI Koichi 金沢医科大学, 医学部, 助教 (60583143)
Co-Investigator(Kenkyū-buntansha)	樋口雅也金沢医科大学, 医学部, 教授 (50334678)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000) Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Keywords	DNA修復 / ゲノム安定性 / 造血幹細胞維持 / 脱ユビキチン化 / DNA損傷応答 / 脱ユビキチン化酵素 / NHEJ経路 / HR経路 / DNA 修復
Outline of Final Research Achievements	Previous study showed Ubiquitin Specific Peptidase 10 (USP10) knockout mouse leads to severe bone marrow failure because of hematopoietic stem cell (HSC) death. In this study, we found genomic instability in USP10-KO MEF cells by testing micronuclei formation, gH2AX foci formation and comet assay. Pulse chase experiment monitoring gH2AX foci suggested that USP10-KO cells failed to repair DNA damage. It is consistent with higher sensitivity to DNA damage inducible reagents in USP10-KO MEF. We also found USP10-KO MEF reduced Homologous Recombination (HR) efficiency. In consistent with this, we observed significant increase the number of chromosome bridges due to the improper DNA end ligaiton. We further found the DNA-PKcs and a phosphatase of DNA-PKcs PPP6C rescued the USP10-KO dependent DNA damage repair defect as described above. Those results suggest that USP10 facilitates PPP6C to repress DNA-PKcs dependent DNA repair to gain accurate repair HR pathway.
Academic Significance and Societal Importance of the Research Achievements	本研究では、USP10が末端結合修復を抑制し、正確性の高い組み替え修復機構選択を促進することを示した。組み替え修復機構の破綻による造血幹細胞の消失はファンコーニ貧血原因遺伝子群で見られ、間接的ではあるがUSP10-KOの表現型はこの機構と同様であると推察される。そしてDNA-PKcsのリン酸化部位の変異体マウスもまたUSP10欠失マウスと酷似した表現型を呈するが、USP10同様に自発的に発現する。この点は、擬似ウイルス感染などによる外部刺激を必要とするファンコーニ貧血遺伝子とは異なる。故に本研究結果は未解明であるファンコーニ遺伝子群の造血幹細胞消失の機序を理解するために重要な知見となる。