Identification of molecules that regulate the deformability of insect cells

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K19296
• 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: Kyoto University
• Principal Investigator: Umeda Masato 京都大学, 工学研究科, 名誉教授 (10185069)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Keywords: ショウジョウバエ / 細胞 / 変形能 / リン脂質 / 細胞骨格 / リン脂質スクランブラーゼ / 細胞膜

Outline of Final Research Achievements

In this study, we demonstrate that Drosophila and Aedes have highly elastic cell membranes with extremely low membrane tension and high resistance to mechanical stress. In contrast to other eukaryotic cells, phospholipids are symmetrically distributed between the bilayer leaflets of the insect plasma membrane, where phospholipid scramblase (XKR) that disrupts the lipid asymmetry is constitutively active. We also demonstrate that XKR-facilitated phospholipid scrambling promotes the deformability of cell membranes by regulating both actin cortex dynamics and mechanical properties of the phospholipid bilayer. Moreover, XKR-mediated construction of elastic cell membranes is essential for hemocyte circulation in the Drosophila cardiovascular system. Deformation of mammalian cells is also enhanced by expression of Aedes XKR, thus phospholipid scrambling may contribute to formation of highly deformable cell membranes in a variety of living eukaryotic cells.

Free Research Field

生化学　細胞生物学

Academic Significance and Societal Importance of the Research Achievements

昆虫は地球上で最も多様化を遂げ繁栄している動物種であり、その中には進化過程において極度な小型化を達成した昆虫種も存在する。これらの微小昆虫も、大型高等動物と同様の複雑に構築された脳・神経組織、循環・消化器系を有している。従来、昆虫の小型化については、その形態学的な特性について研究が進められているが、その微小組織を構築する分子基盤についての研究はなされていない。本研究は、小型昆虫が極めて変形能が高い特異な細胞を有することを明らかにし、そのユニークな物理化学的特性を司る分子レベルでのメカニズムを明らかにした。