Activation of the yeast Arp2/3 complex by Bee1p, a WASP-family protein

Dirk Winter, Terry Lechler, Rong Li

Research output: Contribution to journalArticle

Abstract

The Arp2/3 complex is a highly conserved cytoskeletal component that has been implicated in the nucleation of actin filament assembly. Purified Arp2/3 complex has a low intrinsic actin nucleation activity, leading to the hypothesis that an unidentified cellular activator is required for the function of this complex. We showed previously that mutations in the Arp2/3 complex and in Bee1p/Las17p, a member of the Wiskott-Aldrich syndrome protein (WASP) family, lead to a loss of cortical actin structures (patches) in yeast. Bee1p has also been identified as an essential nucleation factor in the reconstitution of actin patches in vitro. Recently, it was reported that WASP-like proteins might interact directly with the Arp2/3 complex through a conserved carboxy-terminal domain. Here, we have shown that Bee1p and the Arp2/3 complex co-immunoprecipitate when expressed at endogenous levels, and that this interaction requires both the Arc15p and Arc19p subunits of the Arp2/3 complex. Furthermore, the carboxyterminal domain of Bee1p greatly stimulated the nucleation activity of purified Arp2/3 complex in vitro, suggesting a direct role for WASP-family proteins in the activation of the Arp2/3 complex. Interestingly, deletion of the carboxy-terminal domain of Bee1p neither abolished the localization of the Arp2/3 complex, as had been suggested, nor resulted in a severe defect in cortical actin assembly. These results indicate that the function of Bee1p is not mediated entirely through its interaction with the Arp2/3 complex, and that factors redundant with Bee1p might exist to activate the nucleation activity of the Arp2/3 complex.

Original languageEnglish (US)
Pages (from-to)501-504
Number of pages4
JournalCurrent Biology
Volume9
Issue number9
DOIs
StatePublished - May 6 1999
Externally publishedYes

Fingerprint

Wiskott-Aldrich Syndrome Protein Family
Actin-Related Protein 2-3 Complex
Yeast
Yeasts
Chemical activation
actin
yeasts
Proteins
Actins
proteins
Nucleation
microfilaments
Wiskott-Aldrich Syndrome Protein
mutation
Actin Cytoskeleton

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)

Cite this

Activation of the yeast Arp2/3 complex by Bee1p, a WASP-family protein. / Winter, Dirk; Lechler, Terry; Li, Rong.

In: Current Biology, Vol. 9, No. 9, 06.05.1999, p. 501-504.

Research output: Contribution to journalArticle

Winter, Dirk ; Lechler, Terry ; Li, Rong. / Activation of the yeast Arp2/3 complex by Bee1p, a WASP-family protein. In: Current Biology. 1999 ; Vol. 9, No. 9. pp. 501-504.
@article{5370561ac60e4ee695938763932ee3a1,
title = "Activation of the yeast Arp2/3 complex by Bee1p, a WASP-family protein",
abstract = "The Arp2/3 complex is a highly conserved cytoskeletal component that has been implicated in the nucleation of actin filament assembly. Purified Arp2/3 complex has a low intrinsic actin nucleation activity, leading to the hypothesis that an unidentified cellular activator is required for the function of this complex. We showed previously that mutations in the Arp2/3 complex and in Bee1p/Las17p, a member of the Wiskott-Aldrich syndrome protein (WASP) family, lead to a loss of cortical actin structures (patches) in yeast. Bee1p has also been identified as an essential nucleation factor in the reconstitution of actin patches in vitro. Recently, it was reported that WASP-like proteins might interact directly with the Arp2/3 complex through a conserved carboxy-terminal domain. Here, we have shown that Bee1p and the Arp2/3 complex co-immunoprecipitate when expressed at endogenous levels, and that this interaction requires both the Arc15p and Arc19p subunits of the Arp2/3 complex. Furthermore, the carboxyterminal domain of Bee1p greatly stimulated the nucleation activity of purified Arp2/3 complex in vitro, suggesting a direct role for WASP-family proteins in the activation of the Arp2/3 complex. Interestingly, deletion of the carboxy-terminal domain of Bee1p neither abolished the localization of the Arp2/3 complex, as had been suggested, nor resulted in a severe defect in cortical actin assembly. These results indicate that the function of Bee1p is not mediated entirely through its interaction with the Arp2/3 complex, and that factors redundant with Bee1p might exist to activate the nucleation activity of the Arp2/3 complex.",
author = "Dirk Winter and Terry Lechler and Rong Li",
year = "1999",
month = "5",
day = "6",
doi = "10.1016/S0960-9822(99)80218-8",
language = "English (US)",
volume = "9",
pages = "501--504",
journal = "Current Biology",
issn = "0960-9822",
publisher = "Cell Press",
number = "9",

}

TY - JOUR

T1 - Activation of the yeast Arp2/3 complex by Bee1p, a WASP-family protein

AU - Winter, Dirk

AU - Lechler, Terry

AU - Li, Rong

PY - 1999/5/6

Y1 - 1999/5/6

N2 - The Arp2/3 complex is a highly conserved cytoskeletal component that has been implicated in the nucleation of actin filament assembly. Purified Arp2/3 complex has a low intrinsic actin nucleation activity, leading to the hypothesis that an unidentified cellular activator is required for the function of this complex. We showed previously that mutations in the Arp2/3 complex and in Bee1p/Las17p, a member of the Wiskott-Aldrich syndrome protein (WASP) family, lead to a loss of cortical actin structures (patches) in yeast. Bee1p has also been identified as an essential nucleation factor in the reconstitution of actin patches in vitro. Recently, it was reported that WASP-like proteins might interact directly with the Arp2/3 complex through a conserved carboxy-terminal domain. Here, we have shown that Bee1p and the Arp2/3 complex co-immunoprecipitate when expressed at endogenous levels, and that this interaction requires both the Arc15p and Arc19p subunits of the Arp2/3 complex. Furthermore, the carboxyterminal domain of Bee1p greatly stimulated the nucleation activity of purified Arp2/3 complex in vitro, suggesting a direct role for WASP-family proteins in the activation of the Arp2/3 complex. Interestingly, deletion of the carboxy-terminal domain of Bee1p neither abolished the localization of the Arp2/3 complex, as had been suggested, nor resulted in a severe defect in cortical actin assembly. These results indicate that the function of Bee1p is not mediated entirely through its interaction with the Arp2/3 complex, and that factors redundant with Bee1p might exist to activate the nucleation activity of the Arp2/3 complex.

AB - The Arp2/3 complex is a highly conserved cytoskeletal component that has been implicated in the nucleation of actin filament assembly. Purified Arp2/3 complex has a low intrinsic actin nucleation activity, leading to the hypothesis that an unidentified cellular activator is required for the function of this complex. We showed previously that mutations in the Arp2/3 complex and in Bee1p/Las17p, a member of the Wiskott-Aldrich syndrome protein (WASP) family, lead to a loss of cortical actin structures (patches) in yeast. Bee1p has also been identified as an essential nucleation factor in the reconstitution of actin patches in vitro. Recently, it was reported that WASP-like proteins might interact directly with the Arp2/3 complex through a conserved carboxy-terminal domain. Here, we have shown that Bee1p and the Arp2/3 complex co-immunoprecipitate when expressed at endogenous levels, and that this interaction requires both the Arc15p and Arc19p subunits of the Arp2/3 complex. Furthermore, the carboxyterminal domain of Bee1p greatly stimulated the nucleation activity of purified Arp2/3 complex in vitro, suggesting a direct role for WASP-family proteins in the activation of the Arp2/3 complex. Interestingly, deletion of the carboxy-terminal domain of Bee1p neither abolished the localization of the Arp2/3 complex, as had been suggested, nor resulted in a severe defect in cortical actin assembly. These results indicate that the function of Bee1p is not mediated entirely through its interaction with the Arp2/3 complex, and that factors redundant with Bee1p might exist to activate the nucleation activity of the Arp2/3 complex.

UR - http://www.scopus.com/inward/record.url?scp=0033528995&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033528995&partnerID=8YFLogxK

U2 - 10.1016/S0960-9822(99)80218-8

DO - 10.1016/S0960-9822(99)80218-8

M3 - Article

C2 - 10322115

AN - SCOPUS:0033528995

VL - 9

SP - 501

EP - 504

JO - Current Biology

JF - Current Biology

SN - 0960-9822

IS - 9

ER -