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α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction
We have developed an in vitro assay to study actin assembly at cadherin-enriched cell junctions. Using this assay, we demonstrate that cadherin-enriched junctions can polymerize new actin filaments but cannot capture preexisting filaments, suggesting a mechanism involving de novo synthesis. In agree...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3255975/ https://www.ncbi.nlm.nih.gov/pubmed/22232703 http://dx.doi.org/10.1083/jcb.201103116 |
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author | Tang, Vivian W. Brieher, William M. |
author_facet | Tang, Vivian W. Brieher, William M. |
author_sort | Tang, Vivian W. |
collection | PubMed |
description | We have developed an in vitro assay to study actin assembly at cadherin-enriched cell junctions. Using this assay, we demonstrate that cadherin-enriched junctions can polymerize new actin filaments but cannot capture preexisting filaments, suggesting a mechanism involving de novo synthesis. In agreement with this hypothesis, inhibition of Arp2/3-dependent nucleation abolished actin assembly at cell–cell junctions. Reconstitution biochemistry using the in vitro actin assembly assay identified α-actinin-4/focal segmental glomerulosclerosis 1 (FSGS1) as an essential factor. α-Actinin-4 specifically localized to sites of actin incorporation on purified membranes and at apical junctions in Madin–Darby canine kidney cells. Knockdown of α-actinin-4 decreased total junctional actin and inhibited actin assembly at the apical junction. Furthermore, a point mutation of α-actinin-4 (K255E) associated with FSGS failed to support actin assembly and acted as a dominant negative to disrupt actin dynamics at junctional complexes. These findings demonstrate that α-actinin-4 plays an important role in coupling actin nucleation to assembly at cadherin-based cell–cell adhesive contacts. |
format | Online Article Text |
id | pubmed-3255975 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-32559752012-07-09 α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction Tang, Vivian W. Brieher, William M. J Cell Biol Research Articles We have developed an in vitro assay to study actin assembly at cadherin-enriched cell junctions. Using this assay, we demonstrate that cadherin-enriched junctions can polymerize new actin filaments but cannot capture preexisting filaments, suggesting a mechanism involving de novo synthesis. In agreement with this hypothesis, inhibition of Arp2/3-dependent nucleation abolished actin assembly at cell–cell junctions. Reconstitution biochemistry using the in vitro actin assembly assay identified α-actinin-4/focal segmental glomerulosclerosis 1 (FSGS1) as an essential factor. α-Actinin-4 specifically localized to sites of actin incorporation on purified membranes and at apical junctions in Madin–Darby canine kidney cells. Knockdown of α-actinin-4 decreased total junctional actin and inhibited actin assembly at the apical junction. Furthermore, a point mutation of α-actinin-4 (K255E) associated with FSGS failed to support actin assembly and acted as a dominant negative to disrupt actin dynamics at junctional complexes. These findings demonstrate that α-actinin-4 plays an important role in coupling actin nucleation to assembly at cadherin-based cell–cell adhesive contacts. The Rockefeller University Press 2012-01-09 /pmc/articles/PMC3255975/ /pubmed/22232703 http://dx.doi.org/10.1083/jcb.201103116 Text en © 2012 Tang and Brieher This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/). |
spellingShingle | Research Articles Tang, Vivian W. Brieher, William M. α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction |
title | α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction |
title_full | α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction |
title_fullStr | α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction |
title_full_unstemmed | α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction |
title_short | α-Actinin-4/FSGS1 is required for Arp2/3-dependent actin assembly at the adherens junction |
title_sort | α-actinin-4/fsgs1 is required for arp2/3-dependent actin assembly at the adherens junction |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3255975/ https://www.ncbi.nlm.nih.gov/pubmed/22232703 http://dx.doi.org/10.1083/jcb.201103116 |
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