Purification and architecture of the ubiquitous Wave complex

Gautreau, Alexis; Ho, Hsin‐Yi Henry; Li, Jiaxu; Steen, Hanno; Gygi, Steven P.; Kirschner, Marc W.

doi:10.1073/pnas.0400628101

Cited by 212 publications

(308 citation statements)

References 23 publications

Supporting

Mentioning

286

Contrasting

Order By: Relevance

“…WRC is composed of five subunits, namely SCAR/WAVE, Sra1/ PIR121, Nap1, Abi and HSPC300 (Gautreau et al, 2004). In human cells, paralogous genes give rise to SCAR/WAVE1, WAVE2 and WAVE3, Sra1 and PIR121, and Abi1 and Abi2 to generate divergent WRC combinations.…”

Section: Resultsmentioning

confidence: 99%

The Drosophila Arf1 homologue Arf79F is essential for lamellipodium formation

Humphreys

Liu

Davidson

et al. 2012

Journal of Cell Science

View full text Add to dashboard Cite

SummaryThe WAVE regulatory complex (WRC) drives the polymerisation of actin filaments located beneath the plasma membrane to generate lamellipodia that are pivotal to cell architecture and movement. By reconstituting WRC-dependent actin assembly at the membrane, we recently discovered that several classes of Arf family GTPases directly recruit and activate WRC in cell extracts, and that Arf cooperates with Rac1 to trigger actin polymerisation. Here, we demonstrate that the Class 1 Arf1 homologue Arf79F colocalises with the WRC at dynamic lamellipodia. We report that Arf79F is required for lamellipodium formation in Drosophila S2R+ cells, which only express one Arf isoform for each class. Impeding Arf function either by dominant-negative Arf expression or by Arf doublestranded RNA interference (dsRNAi)-mediated knockdown uncovered that Arf-dependent lamellipodium formation was specific to Arf79F, establishing that Class 1 Arfs, but not Class 2 or Class 3 Arfs, are crucial for lamellipodia. Lamellipodium formation in Arf79F-silenced cells was restored by expressing mammalian Arf1, but not by constitutively active Rac1, showing that Arf79F does not act via Rac1. Abolition of lamellipodium formation in Arf79F-silenced cells was not due to Golgi disruption. Blocking Arf79F activation with guanine nucleotide exchange factor inhibitors impaired WRC localisation to the plasma membrane and concomitant generation of lamellipodia. Our data indicate that the Class I Arf GTPase is a central component in WRC-driven lamellipodium formation.

show abstract

Section: Resultsmentioning

confidence: 99%

The Drosophila Arf1 homologue Arf79F is essential for lamellipodium formation

Humphreys

Liu

Davidson

et al. 2012

Journal of Cell Science

View full text Add to dashboard Cite

show abstract

“…For example, mutant complementation tests indicate that human W/SRC and ARP2/3 complex subunits can substitute for the Arabidopsis proteins (Mathur et al, 2003b). Furthermore, biochemical assays of Arabidopsis W/SRC El-Assal et al, 2004;Frank et al, 2004;Le et al, 2006;Uhrig et al, 2007) and ARP2/ 3 assembly (Kotchoni et al, 2009) have shown that the binary interactions among W/SRC subunits and ARP2/3 complex assembly mechanisms are indistinguishable from those that have been observed for human W/SRC (Gautreau et al, 2004) and yeast ARP2/3 (Winter et al, 1999). After an initial period of controversy concerning the biochemical control of W/SRC, it is now apparent that vertebrate W/SRC (Derivery et al, 2009;Ismail et al, 2009), like the ARP2/3 complex (Machesky et al, 1999), is intrinsically inactive and requires positive regulation by Rac and other factors to fully activate ARP2/3 (Ismail et al, 2009;Lebensohn and Kirschner, 2009;Chen et al, 2010).…”

mentioning

confidence: 99%

“…Based on the equally severe syndrome of nap1 and arp2/3 null phenotypes, and double mutant analyses, the only known function of NAP1 is to positively regulate ARP2/3 (Brembu et al, 2004;Deeks et al, 2004;El-Din El-Assal et al, 2004;Li et al, 2004). The vertebrate SRA1-NAP1 dimer is important for W/SRC assembly (Gautreau et al, 2004) and forms an extended physical surface that trans-inhibits the C-terminal ARP2/3-activating domain of WAVE/SCAR . The plant NAP1 and SRA1 proteins share endto-end amino acid conservation with their vertebrate homologs and may form a heterodimer with similar functions El-Assal et al, 2004;Uhrig et al, 2007).…”

mentioning

confidence: 99%

The Endoplasmic Reticulum Is a Reservoir for WAVE/SCAR Regulatory Complex Signaling in the Arabidopsis Leaf

et al. 2013

View full text Add to dashboard Cite

During plant cell morphogenesis, signal transduction and cytoskeletal dynamics interact to locally organize the cytoplasm and define the geometry of cell expansion. The WAVE/SCAR (for WASP family verprolin homologous/suppressor of cyclic AMP receptor) regulatory complex (W/SRC) is an evolutionarily conserved heteromeric protein complex. Within the plant kingdom W/SRC is a broadly used effector that converts Rho-of-Plants (ROP)/Rac small GTPase signals into Actin-Related Protein2/3 and actin-dependent growth responses. Although the components and biochemistry of the W/SRC pathway are well understood, a basic understanding of how cells partition W/SRC into active and inactive pools is lacking. In this paper, we report that the endoplasmic reticulum (ER) is an important organelle for W/SRC regulation. We determined that a large intracellular pool of the core W/SRC subunit NAP1, like the known positive regulator of W/SRC, the DOCK family guanine nucleotide-exchange factor SPIKE1 (SPK1), localizes to the surface of the ER. The ER-associated NAP1 is inactive because it displays little colocalization with the actin network, and ER localization requires neither activating signals from SPK1 nor a physical association with its W/SRC-binding partner, SRA1. Our results indicate that in Arabidopsis (Arabidopsis thaliana) leaf pavement cells and trichomes, the ER is a reservoir for W/SRC signaling and may have a key role in the early steps of W/SRC assembly and/or activation.

show abstract

“…If the Arabidopsis SCAR proteins identified function in a complex containing AtBRK1, then we could expect that they would bind directly to AtBRK1, because HSPC300 has been shown to bind directly to WAVE1 and WAVE2 (10,11). Therefore, full-length AtSCAR3 and AtSCAR1 were produced by in vitro transcription͞translation in the presence of [ 35 S]methionine together with T7 epitope-tagged AtBRK1 or two different T7-tagged negative control proteins (NC1 and NC2).…”

Section: Full-length Atscar Proteins and Their N-terminal Sh Domainsmentioning

confidence: 99%

“…However, recent work has identified plant homologs of three components of a mammalian WAVE-containing complex isolated from brain and HeLa cell extracts, which functions to regulate the localization and activity of WAVE͞Scar in vitro and in vivo (10)(11)(12). The first of these to be identified, BRK1, is a homolog of human HSPC300.…”

mentioning

confidence: 99%