Nucleotide- and Activator-Dependent Structural and Dynamic Changes of Arp2/3 Complex Monitored by Hydrogen/Deuterium Exchange and Mass Spectrometry

JOURNAL OF MOLECULAR BIOLOGY

卷:390

Article

Zencheck, Wendy D.¹  Xiao, Hui^2,3  Nolen, Brad J.^4,5  Angeletti, Ruth Hogue^1,3,6  Pollard, Thomas D.^7,8,9  Almo, Steven C.^1,10 

[1] Yeshiva Univ Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA

[2] Yeshiva Univ Albert Einstein Coll Med, Dept Pathol, Bronx, NY 10461 USA

[3] Yeshiva Univ Albert Einstein Coll Med, Lab Macromol Anal & Prote, Bronx, NY 10461 USA

[4] Univ Oregon, Dept Chem, Eugene, OR 97403 USA

[5] Univ Oregon, Inst Mol Biol, Eugene, OR 97403 USA

[6] Yeshiva Univ Albert Einstein Coll Med, Dept Dev & Mol Biol, Bronx, NY 10461 USA

[7] Yale Univ, Dept Mol Cellular & Dev Biol, New Haven, CT 06520 USA

[8] Yale Univ, Dept Cell Biol, New Haven, CT 06520 USA

[9] Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA

[10] Yeshiva Univ Albert Einstein Coll Med, Dept Physiol & Biophys, Bronx, NY 10461 USA

关键词: Arp2/3;    actin;    cytoskeleton;    amide hydrogen/deuterium exchange;    dynamics;   

DOI  :  10.1016/j.jmb.2009.03.028

来源: Elsevier

【 摘 要 】

Arp2/3 complex plays a central role in the de novo nucleation of filamentous actin as branches on existing filaments. The complex must bind ATP, protein activators [e.g., Wiskott-Aldrich syndrome protein (WASp)], and the side of an actin filament to form a new actin filament. Amide hydrogen/deuterium exchange coupled with mass spectrometry was used to examine the structural and dynamic properties of the mammalian Arp2/3 complex in the presence of both ATP and the activating peptide segment from WASp. Changes in the rate of hydrogen exchange indicate that ATP binding causes conformational rearrangements of Arp2 and Arp3 that are transmitted allosterically to the Arp complex (ARPC)1, ARPC2, ARPC4, and ARPC5 subunits. These data are consistent with the closure of nucleotide-binding cleft of Arp3 upon ATP binding, resulting in structural rearrangements that propagate throughout the complex. Binding of the VCA domain of WASp to ATP-Arp2/3 further modulates the rates of hydrogen exchange in these subunits, indicating that a global conformational reorganization is occurring. These effects may include the direct binding of activators to Arp3, Arp2, and ARPC1; alterations in the relative orientations of Arp2 and Arp3; and the long-range transmission of activator-dependent signals to segments proposed to be involved in binding the F-actin mother filament. (C) 2009 Elsevier Ltd. All rights reserved.

【 授权许可】

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