精子中心装置の構造が男性不妊の分子基盤を解明(In-situ Structure of Sperm Central Apparatus Reveals Molecular Basis of Male Infertility)

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2025-06-09 中国科学院(CAS)

精子中心装置の構造が男性不妊の分子基盤を解明(In-situ Structure of Sperm Central Apparatus Reveals Molecular Basis of Male Infertility)Schematic Diagram of the In Situ Structure of Mouse Sperm Axonemal Central Apparatus (Image by SUN Fei’s group)

中国科学院生物物理研究所などの研究チームは、哺乳類精子の軸糸内に存在する中央装置(CA)の高解像度in situ構造を初めて解明しました。CAは運動性線毛・鞭毛の中心構造で、精子の運動や発生、脳機能、呼吸に不可欠ですが、その詳細は不明でした。本研究では、先端的なクライオ電子トモグラフィーとAlphaFold2などのAI技術を活用し、マウス精子のCA構造を原子レベルに近い分解能で再構築。C1-C2微小管とその関連タンパク質の組立様式を明らかにし、運動障害(精子無力症)の病因機構を説明しました。さらに466のタンパク質サブユニットを含む構造モデルを構築し、GRK3など新たなCA構成因子8種を同定。本研究は男性不妊の診断・治療戦略への新たな知見を提供するものです。

<関連情報>

マウス精子中枢器官の原位置構造が精子無力症のメカニズムに関する洞察を明らかにする In situ structure of the mouse sperm central apparatus reveals mechanistic insights into asthenozoospermia

Yun Zhu,Tingting Lin,Guoliang Yin,Linhua Tai,Lianwan Chen,Jing Ma,Guoning Huang,Yi Lu,Zhiyong Zhang,Binbin Wang,Suren Chen & Fei Sun
Cell Research  Published:05 June 2025
DOI:https://doi.org/10.1038/s41422-025-01135-2

Abstract

The central apparatus (CA) within the sperm axoneme is vital for sperm motility, yet its molecular architecture and functional mechanisms remain incompletely understood. Combining cryo-electron tomography and AlphaFold2, we resolved the in-cell structure of mouse sperm CA at a subnanometer resolution and built a near-complete atomic model. Our analysis identified 39 CA-associated proteins, including eight previously unreported components. By presenting the full-length structures of CFAP47 and HYDIN, we elucidate their molecular roles in tethering the C1 and C2 microtubules within the CA. Specifically, HYDIN forms a semicircular chain that encircles C1 and C2, with its N-terminal half driving the C1–C2 connection and its C-terminal half providing axial support in C2. CFAP47, the core structural component of the bridge, binds C1 through its N-terminal domains, interacts with HYDIN via its central CFAP47-ring, and anchors to C2 through its C-terminal region. The significantly reduced sperm motility and impaired CA structure observed in Cfap47-knockout mice confirmed the important role of CFAP47. Furthermore, genetic analysis of infertile Chinese men with asthenozoospermia identified previously unreported mutations in the CFAP47. The CA structural model elucidates the pathogenic mechanisms of these mutations, establishing a direct link between CFAP47 dysfunction and impaired sperm motility. Therefore, our study provides mechanistic insights into CA-related fertility disorders.

生物工学一般
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