ジャーナル: J Cell Biol / 年: 2018 タイトル: Structural insight into microtubule stabilization and kinesin inhibition by Tau family MAPs. 著者: Hideki Shigematsu / Tsuyoshi Imasaki / Chihiro Doki / Takuya Sumi / Mari Aoki / Tomomi Uchikubo-Kamo / Ayako Sakamoto / Kiyotaka Tokuraku / Mikako Shirouzu / Ryo Nitta / 要旨: The Tau family microtubule-associated proteins (MAPs) promote microtubule stabilization and regulate microtubule-based motility. They share the C-terminal microtubule-binding domain, which includes ...The Tau family microtubule-associated proteins (MAPs) promote microtubule stabilization and regulate microtubule-based motility. They share the C-terminal microtubule-binding domain, which includes three to five tubulin-binding repeats. Different numbers of repeats formed by alternative splicing have distinct effects on the activities of these proteins, and the distribution of these variants regulates fundamental physiological phenomena in cells. In this study, using cryo-EM, we visualized the MAP4 microtubule complex with the molecular motor kinesin-1. MAP4 bound to the C-terminal domains of tubulins along the protofilaments stabilizes the longitudinal contacts of the microtubule. The strongest bond of MAP4 was found around the intertubulin-dimer interface such that MAP4 coexists on the microtubule with kinesin-1 bound to the intratubulin-dimer interface as well. MAP4, consisting of five repeats, further folds and accumulates above the intertubulin-dimer interface, interfering with kinesin-1 movement. Therefore, these cryo-EM studies reveal new insight into the structural basis of microtubule stabilization and inhibition of kinesin motility by the Tau family MAPs.
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 300 K / 装置: FEI VITROBOT MARK IV / 詳細: Blot time 5sec, Blot Force 20.
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電子顕微鏡法
顕微鏡
FEI TECNAI ARCTICA
詳細
Alignment procedure by FEI User Interface Software. Not determined the residual tilt value.
撮影
フィルム・検出器のモデル: FEI FALCON II (4k x 4k) 検出モード: INTEGRATING / デジタル化 - 画像ごとのフレーム数: 1-34 / 撮影したグリッド数: 1 / 平均露光時間: 2.0 sec. / 平均電子線量: 55.0 e/Å2 詳細: Images were collected in movie-mode at 17 frames per second by using Falcon Hack developed by Greg McMullan