Protein-protein interaction analysis focusing on mutational hotspots in cancer genome

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19403
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 47:Pharmaceutical sciences and related fields
• Research Institution: Osaka University
• Principal Investigator: Hino Nobumasa 大阪大学, 薬学研究科, 助教 (90469916)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: がんゲノム / 遺伝子変異 / タンパク質立体構造 / タンパク質間相互作用 / 光クロスリンク / 人工アミノ酸 / KEAP1

Outline of Final Research Achievements

We aimed to establish a strategy for identifying protein-protein interactions affected by cancer mutations. By combining datasets of cancer genome mutation and 3D protein structure, we identified structural mutations cluster on the protein surface of KEAP1. We analyzed proteins binding to this surface by in vivo site-specific photo-cross-linking approach and identified Rab8a. Rab8a contributes to cell migration through the recruitment of MT1-MMP to the plasma membrane. Actually, Rab8a gene knockdown reduced cell migration activity, while additional KEAP1 knockdown cancelled this effect, suggesting that KEAP1 negatively regulates Rab8a activity. Furthermore, KEAP1 blocked MT1-MMP transport by tethering Rab8a in the perinuclear region, and the KEAP1 mutation disrupted its interaction with Rab8a, releasing the Rab8a-MT1-MMP complex. These results indicate that the focused analysis on structural mutations cluster can identify protein-protein interactions affected by cancer mutations.

Free Research Field

ケミカルバイオロジー

Academic Significance and Societal Importance of the Research Achievements

これまでのがんゲノム創薬研究は既知のがん遺伝子変異をターゲットにしたものがほとんどであり．新規創薬標的の枯渇が問題視されている現状を鑑みると，その研究の方向性を大きくシフトする必要がある．本研究は，これまでほとんど利用されてこなかった低頻度変異情報から新たな創薬標的を見出す戦略を確立することを目指し，実際に，がん変異により異常をきたす新たなタンパク質間相互作用を発見することに成功した．