Interaction of WASP/Scar proteins with actin and vertebrate Arp2/3 complex

被引：262

作者：

Marchand, JB ^{[1
]}

Kaiser, DA ^{[1
]}

Pollard, TD ^{[1
]}

Higgs, HN ^{[1
]}

机构：

[1] Salk Inst Biol Studies, Struct Biol Lab, La Jolla, CA 92037 USA

来源：

NATURE CELL BIOLOGY | 2001年 / 3卷 / 01期

关键词：

D O I：

10.1038/35050590

中图分类号：

Q2 [细胞生物学];

学科分类号：

071009 ; 090102 ;

摘要：

The Wiskott-Aldrich-syndrome protein (WASP) regulates polymerization of actin by the Arp2/3 complex. Here we show, using fluorescence anisotropy assays, that the carboxy-terminal WA domain of WASP binds to a single actin monomer with a K-d of 0.6 muM in an equilibrium with rapid exchange rates. Both WH-2 and CA sequences contribute to actin binding. A favourable DeltaH of -10 kcal mol(-1) drives binding. The WA domain binds to the Arp2/3 complex with a K-d of 0.9 muM; both the C and A sequences contribute to binding to the Arp2/3 complex. Wiskott-Aldrich-syndrome mutations in the WA domain that alter nucleation by the Arp2/3 complex over a tenfold range without affecting affinity for actin or the Arp2/3 complex indicate that there may be an activation step in the nucleation pathway. Actin filaments stimulate nucleation by producing a fivefold increase in the affinity of WASP-WA for the Arp2/3 complex.

引用

页码：76 / 82

页数：7