National Institutes of Health/National Institute on Deafness and Other Communication Disorders (NIH/NIDCD)
R01 DC019833
米国
引用
ジャーナル: Nature / 年: 2021 タイトル: The conformational cycle of prestin underlies outer-hair cell electromotility. 著者: Navid Bavi / Michael David Clark / Gustavo F Contreras / Rong Shen / Bharat G Reddy / Wieslawa Milewski / Eduardo Perozo / 要旨: The voltage-dependent motor protein prestin (also known as SLC26A5) is responsible for the electromotive behaviour of outer-hair cells and underlies the cochlear amplifier. Knockout or impairment of ...The voltage-dependent motor protein prestin (also known as SLC26A5) is responsible for the electromotive behaviour of outer-hair cells and underlies the cochlear amplifier. Knockout or impairment of prestin causes severe hearing loss. Despite the key role of prestin in hearing, the mechanism by which mammalian prestin senses voltage and transduces it into cellular-scale movements (electromotility) is poorly understood. Here we determined the structure of dolphin prestin in six distinct states using single-particle cryo-electron microscopy. Our structural and functional data suggest that prestin adopts a unique and complex set of states, tunable by the identity of bound anions (Cl or SO). Salicylate, a drug that can cause reversible hearing loss, competes for the anion-binding site of prestin, and inhibits its function by immobilizing prestin in a new conformation. Our data suggest that the bound anion together with its coordinating charged residues and helical dipole act as a dynamic voltage sensor. An analysis of all of the anion-dependent conformations reveals how structural rearrangements in the voltage sensor are coupled to conformational transitions at the protein-membrane interface, suggesting a previously undescribed mechanism of area expansion. Visualization of the electromotility cycle of prestin distinguishes the protein from the closely related SLC26 anion transporters, highlighting the basis for evolutionary specialization of the mammalian cochlear amplifier at a high resolution.
pH: 7.4 / 構成要素 - 濃度: 125.0 mM / 構成要素 - 式: Na2SO4 / 構成要素 - 名称: sodium sulfate 詳細: 125 mM Na2SO4, 5mM Mg(OH)2, 20 mM Tris-OH, 10-15 mM methanesulfonic acid + 0.02 % GDN + 50 mM Sodium Salicylate
グリッド
モデル: Quantifoil R1.2/1.3 / 支持フィルム - 材質: CARBON
凍結
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 295 K / 装置: FEI VITROBOT MARK IV 詳細: 4.5 s blot times, blot force 3, and double filter papers on each side of the vitrobot..
詳細
Monodisperse peak at around 14 ml using SEC (Superose 6 column)
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
撮影
フィルム・検出器のモデル: GATAN K3 (6k x 4k) / 平均電子線量: 1.0 e/Å2
電子線
加速電圧: 300 kV / 電子線源: FIELD EMISSION GUN
電子光学系
照射モード: FLOOD BEAM / 撮影モード: BRIGHT FIELD
実験機器
モデル: Titan Krios / 画像提供: FEI Company
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画像解析
初期モデル
モデルのタイプ: PDB ENTRY
最終 再構成
解像度のタイプ: BY AUTHOR / 解像度: 3.7 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 使用した粒子像数: 112000