National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01-GM07391
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
T32-GM008275
米国
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
F31-HL146077
米国
引用
ジャーナル: Sci Adv / 年: 2020 タイトル: Cryo-EM structure of NPF-bound human Arp2/3 complex and activation mechanism. 著者: Austin Zimmet / Trevor Van Eeuwen / Malgorzata Boczkowska / Grzegorz Rebowski / Kenji Murakami / Roberto Dominguez / 要旨: Actin-related protein (Arp) 2/3 complex nucleates branched actin networks that drive cell motility. It consists of seven proteins, including two actin-related subunits (Arp2 and Arp3). Two nucleation- ...Actin-related protein (Arp) 2/3 complex nucleates branched actin networks that drive cell motility. It consists of seven proteins, including two actin-related subunits (Arp2 and Arp3). Two nucleation-promoting factors (NPFs) bind Arp2/3 complex during activation, but the order, specific interactions, and contribution of each NPF to activation are unresolved. Here, we report the cryo-electron microscopy structure of recombinantly expressed human Arp2/3 complex with two WASP family NPFs bound and address the mechanism of activation. A cross-linking assay that captures the transition of the Arps into the activated filament-like conformation shows that actin binding to NPFs favors this transition. Actin-NPF binding to Arp2 precedes binding to Arp3 and is sufficient to promote the filament-like conformation but not activation. Structure-guided mutagenesis of the NPF-binding sites reveals their distinct roles in activation and shows that, contrary to budding yeast Arp2/3 complex, NPF-mediated delivery of actin at the barbed end of both Arps is required for activation of human Arp2/3 complex.
ChemComp-ATP: ADENOSINE-5'-TRIPHOSPHATE / ATP / ATP, エネルギー貯蔵分子*YM
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実験情報
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構造解析
手法
クライオ電子顕微鏡法
解析
単粒子再構成法
試料の集合状態
particle
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試料調製
濃度
5 mg/mL
緩衝液
pH: 7 構成要素:
濃度
式
名称
20.0 mM
C8H18N2O4S
HEPES
100.0 mM
NaCl
sodium chloride
1.0 mM
HSCH2CH(OH)CH(OH)CH2SH
Dithiothreitol
0.2 mM
C10H14N5O13P3Na2
Adenosine triphosphate disodium salt
0.2 mM
MgCl2
magnesium chloride
0.00025 V/V
TERGITOL
グリッド
モデル: Quantifoil R2/2 / 材質: COPPER / メッシュ: 200 / 前処理 - タイプ: GLOW DISCHARGE / 前処理 - 時間: 60 sec. / 前処理 - 雰囲気: AIR 詳細: Grids glow discharged with easiGLOW glow discharger at 0.3 mBar, 25mA for 1 minute
凍結
凍結剤: ETHANE / 装置: LEICA EM CPC 詳細: Grids manually blotted for 3 seconds with Whatman 41 filter paper and manually plunged on Leica EM CPC manual plunger..
詳細
This sample was monodisperse
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
特殊光学系
エネルギーフィルター - スリット幅: 20 eV
詳細
Data collected in super resolution mode. Illuminated area of 1.01um. Nominal Dose of 40a/A^2 and a dose rate of 4.87 e-/s/pixel. 2 or 5 exposures per hole by image shift.