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: Nat Commun / 年: 2022 タイトル: Molecular mechanism of Arp2/3 complex inhibition by Arpin. 著者: Fred E Fregoso / Trevor van Eeuwen / Gleb Simanov / Grzegorz Rebowski / Malgorzata Boczkowska / Austin Zimmet / Alexis M Gautreau / Roberto Dominguez / 要旨: Positive feedback loops involving signaling and actin assembly factors mediate the formation and remodeling of branched actin networks in processes ranging from cell and organelle motility to ...Positive feedback loops involving signaling and actin assembly factors mediate the formation and remodeling of branched actin networks in processes ranging from cell and organelle motility to mechanosensation. The Arp2/3 complex inhibitor Arpin controls the directional persistence of cell migration by interrupting a feedback loop involving Rac-WAVE-Arp2/3 complex, but Arpin's mechanism of inhibition is unknown. Here, we describe the cryo-EM structure of Arpin bound to Arp2/3 complex at 3.24-Å resolution. Unexpectedly, Arpin binds Arp2/3 complex similarly to WASP-family nucleation-promoting factors (NPFs) that activate the complex. However, whereas NPFs bind to two sites on Arp2/3 complex, on Arp2-ArpC1 and Arp3, Arpin only binds to the site on Arp3. Like NPFs, Arpin has a C-helix that binds at the barbed end of Arp3. Mutagenesis studies in vitro and in cells reveal how sequence differences within the C-helix define the molecular basis for inhibition by Arpin vs. activation by NPFs.
凍結剤: ETHANE / 装置: LEICA EM CPC 詳細: Grids were manually blotted for 3 seconds with Whatman 41 filter paper and manually plunged using a 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 were collected in super-resolution mode with an illuminated area of 1.01 um, nominal dose of 40 e-/A^2, a dose rate of 4.87 e-/s/pixel, and 2 or 5 exposures per hole by image shift.