Science:揭示中心體基體車輪狀結構

7月12日，Science在線報導了中心體基體車輪狀結構的最新研究進展，為深入理解諸多有絲分裂異常相關疾病：如腫瘤和某些染色體核型異常遺傳病，打下了良好的基礎。

中心粒和基體對於纖毛，鞭毛，中心體的形成至關重要。中心粒和基體表現為特徵性的九倍對稱車輪狀結構，包含一系列SAS-6蛋白環。

研究者使用冷凍電子斷層成像技術研究鞭毛披髮蟲（flagellate Trichonympha）特別長的車輪結構。結果發現，車輪是一摞垂直周期性為8.5納米，能容納9個SAS-6蛋白同源二聚體的中央環。從兩個這樣的環散發出的輻條狀結構，連結為一個垂直周期性為17納米的層狀結構，環繞於車輪狀結構邊緣。

由此，利用生物多樣性的便利，研究者揭示了中心粒和基體的九倍對稱性車輪結構。（生物谷bioon.com）

Cartwheel Architecture of Trichonympha Basal Body

Paul Guichard1,Ambroise Desfosses2,Aditi Maheshwari3,Virginie Hachet1,Carsten Dietrich4,Andreas Brune4,Takashi Ishikawa3,Carsten Sachse2,Pierre G?nczy1

Centrioles and basal bodies are essential for the formation of cilia, flagella, and centrosomes. Centrioles and basal bodies exhibit a characteristic ninefold symmetry imparted by a cartwheel thought to contain rings of SAS-6 proteins. We used cryoelectron tomography to investigate the architecture of the exceptionally long cartwheel of the flagellate Trichonympha. We found that the cartwheel is a stack of central rings that exhibit a vertical periodicity of 8.5 nanometers and able to accommodate nine SAS-6 homodimers. The spokes that emanate from two such rings associate into a layer, with a vertical periodicity of 17 nanometers on the cartwheel margin. Thus, by using the power of biodiversity, we unveiled the architecture of the cartwheel at the root of the ninefold symmetry of centrioles and basal bodies.