Cargando…

Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing

Early Xenopus embryos are large, and during the egg to gastrula stages, when there is little extracellular matrix, the cytoskeletons of the individual blastomeres are thought to maintain their spherical architecture and provide scaffolding for the cellular movements of gastrulation. We showed previo...

Descripción completa

Detalles Bibliográficos
Autores principales: Kofron, Matthew, Heasman, Janet, Lang, Stephanie A., Wylie, Christopher C.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2002
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2174016/
https://www.ncbi.nlm.nih.gov/pubmed/12186853
http://dx.doi.org/10.1083/jcb.200202123
_version_ 1782145286991249408
author Kofron, Matthew
Heasman, Janet
Lang, Stephanie A.
Wylie, Christopher C.
author_facet Kofron, Matthew
Heasman, Janet
Lang, Stephanie A.
Wylie, Christopher C.
author_sort Kofron, Matthew
collection PubMed
description Early Xenopus embryos are large, and during the egg to gastrula stages, when there is little extracellular matrix, the cytoskeletons of the individual blastomeres are thought to maintain their spherical architecture and provide scaffolding for the cellular movements of gastrulation. We showed previously that depletion of plakoglobin protein during the egg to gastrula stages caused collapse of embryonic architecture. Here, we show that this is due to loss of the cortical actin skeleton after depletion of plakoglobin, whereas the microtubule and cytokeratin skeletons are still present. As a functional assay for the actin skeleton, we show that wound healing, an actin-based behavior in embryos, is also abrogated by plakoglobin depletion. Both wound healing and the amount of cortical actin are enhanced by overexpression of plakoglobin. To begin to identify links between plakoglobin and the cortical actin polymerization machinery, we show here that the Rho family GTPase cdc42, is required for wound healing in the Xenopus blastula. Myc-tagged cdc42 colocalizes with actin in purse-strings surrounding wounds. Overexpression of cdc42 dramatically enhances wound healing, whereas depletion of maternal cdc42 mRNA blocks it. In combinatorial experiments we show that cdc42 cannot rescue the effects of plakoglobin depletion, showing that plakoglobin is required for cdc42-mediated cortical actin assembly during wound healing. However, plakoglobin does rescue the effect of cdc42 depletion, suggesting that cdc42 somehow mediates the distribution or function of plakoglobin. Depletion of α-catenin does not remove the cortical actin skeleton, showing that plakoglobin does not mediate its effect by its known linkage through α-catenin to the actin skeleton. We conclude that in Xenopus, the actin skeleton is a major determinant of cell shape and overall architecture in the early embryo, and that plakoglobin plays an essential role in the assembly, maintenance, or organization of this cortical actin.
format Text
id pubmed-2174016
institution National Center for Biotechnology Information
language English
publishDate 2002
publisher The Rockefeller University Press
record_format MEDLINE/PubMed
spelling pubmed-21740162008-05-01 Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing Kofron, Matthew Heasman, Janet Lang, Stephanie A. Wylie, Christopher C. J Cell Biol Article Early Xenopus embryos are large, and during the egg to gastrula stages, when there is little extracellular matrix, the cytoskeletons of the individual blastomeres are thought to maintain their spherical architecture and provide scaffolding for the cellular movements of gastrulation. We showed previously that depletion of plakoglobin protein during the egg to gastrula stages caused collapse of embryonic architecture. Here, we show that this is due to loss of the cortical actin skeleton after depletion of plakoglobin, whereas the microtubule and cytokeratin skeletons are still present. As a functional assay for the actin skeleton, we show that wound healing, an actin-based behavior in embryos, is also abrogated by plakoglobin depletion. Both wound healing and the amount of cortical actin are enhanced by overexpression of plakoglobin. To begin to identify links between plakoglobin and the cortical actin polymerization machinery, we show here that the Rho family GTPase cdc42, is required for wound healing in the Xenopus blastula. Myc-tagged cdc42 colocalizes with actin in purse-strings surrounding wounds. Overexpression of cdc42 dramatically enhances wound healing, whereas depletion of maternal cdc42 mRNA blocks it. In combinatorial experiments we show that cdc42 cannot rescue the effects of plakoglobin depletion, showing that plakoglobin is required for cdc42-mediated cortical actin assembly during wound healing. However, plakoglobin does rescue the effect of cdc42 depletion, suggesting that cdc42 somehow mediates the distribution or function of plakoglobin. Depletion of α-catenin does not remove the cortical actin skeleton, showing that plakoglobin does not mediate its effect by its known linkage through α-catenin to the actin skeleton. We conclude that in Xenopus, the actin skeleton is a major determinant of cell shape and overall architecture in the early embryo, and that plakoglobin plays an essential role in the assembly, maintenance, or organization of this cortical actin. The Rockefeller University Press 2002-08-19 /pmc/articles/PMC2174016/ /pubmed/12186853 http://dx.doi.org/10.1083/jcb.200202123 Text en Copyright © 2002, The Rockefeller University Press 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 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Kofron, Matthew
Heasman, Janet
Lang, Stephanie A.
Wylie, Christopher C.
Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing
title Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing
title_full Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing
title_fullStr Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing
title_full_unstemmed Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing
title_short Plakoglobin is required for maintenance of the cortical actin skeleton in early Xenopus embryos and for cdc42-mediated wound healing
title_sort plakoglobin is required for maintenance of the cortical actin skeleton in early xenopus embryos and for cdc42-mediated wound healing
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2174016/
https://www.ncbi.nlm.nih.gov/pubmed/12186853
http://dx.doi.org/10.1083/jcb.200202123
work_keys_str_mv AT kofronmatthew plakoglobinisrequiredformaintenanceofthecorticalactinskeletoninearlyxenopusembryosandforcdc42mediatedwoundhealing
AT heasmanjanet plakoglobinisrequiredformaintenanceofthecorticalactinskeletoninearlyxenopusembryosandforcdc42mediatedwoundhealing
AT langstephaniea plakoglobinisrequiredformaintenanceofthecorticalactinskeletoninearlyxenopusembryosandforcdc42mediatedwoundhealing
AT wyliechristopherc plakoglobinisrequiredformaintenanceofthecorticalactinskeletoninearlyxenopusembryosandforcdc42mediatedwoundhealing