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PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli

Scaffolding proteins containing PDZ (postsynaptic density 95/discs large/zonula occludens-1) domains are believed to provide relatively stable linkages between components of macromolecular complexes and in some cases to bridge to the actin cytoskeleton. The microvillar scaffolding protein EBP50 (ERM...

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Autores principales: Garbett, Damien, Bretscher, Anthony
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410424/
https://www.ncbi.nlm.nih.gov/pubmed/22801783
http://dx.doi.org/10.1083/jcb.201204008
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author Garbett, Damien
Bretscher, Anthony
author_facet Garbett, Damien
Bretscher, Anthony
author_sort Garbett, Damien
collection PubMed
description Scaffolding proteins containing PDZ (postsynaptic density 95/discs large/zonula occludens-1) domains are believed to provide relatively stable linkages between components of macromolecular complexes and in some cases to bridge to the actin cytoskeleton. The microvillar scaffolding protein EBP50 (ERM-binding phosphoprotein of 50 kD), consisting of two PDZ domains and an ezrin-binding site, retains specific proteins in microvilli and is necessary for microvillar biogenesis. Our analysis of the dynamics of microvillar proteins in vivo indicated that ezrin and microvillar membrane proteins had dynamics consistent with actin treadmilling and microvillar lifetimes. However, EBP50 was highly dynamic, turning over within seconds. EBP50 turnover was reduced by mutations that inactivate its PDZ domains and was enhanced by protein kinase C phosphorylation. Using a novel in vitro photoactivation fluorescence assay, the EBP50–ezrin interaction was shown to have a slow off-rate that was dramatically enhanced in a PDZ-regulated manner by addition of cell extract to near in vivo levels. Thus, the linking of relatively stable microvillar components can be mediated by surprisingly dynamic EBP50, a finding that may have important ramifications for other scaffolding proteins.
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spelling pubmed-34104242013-01-23 PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli Garbett, Damien Bretscher, Anthony J Cell Biol Research Articles Scaffolding proteins containing PDZ (postsynaptic density 95/discs large/zonula occludens-1) domains are believed to provide relatively stable linkages between components of macromolecular complexes and in some cases to bridge to the actin cytoskeleton. The microvillar scaffolding protein EBP50 (ERM-binding phosphoprotein of 50 kD), consisting of two PDZ domains and an ezrin-binding site, retains specific proteins in microvilli and is necessary for microvillar biogenesis. Our analysis of the dynamics of microvillar proteins in vivo indicated that ezrin and microvillar membrane proteins had dynamics consistent with actin treadmilling and microvillar lifetimes. However, EBP50 was highly dynamic, turning over within seconds. EBP50 turnover was reduced by mutations that inactivate its PDZ domains and was enhanced by protein kinase C phosphorylation. Using a novel in vitro photoactivation fluorescence assay, the EBP50–ezrin interaction was shown to have a slow off-rate that was dramatically enhanced in a PDZ-regulated manner by addition of cell extract to near in vivo levels. Thus, the linking of relatively stable microvillar components can be mediated by surprisingly dynamic EBP50, a finding that may have important ramifications for other scaffolding proteins. The Rockefeller University Press 2012-07-23 /pmc/articles/PMC3410424/ /pubmed/22801783 http://dx.doi.org/10.1083/jcb.201204008 Text en © 2012 Garbett and Bretscher 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
Garbett, Damien
Bretscher, Anthony
PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli
title PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli
title_full PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli
title_fullStr PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli
title_full_unstemmed PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli
title_short PDZ interactions regulate rapid turnover of the scaffolding protein EBP50 in microvilli
title_sort pdz interactions regulate rapid turnover of the scaffolding protein ebp50 in microvilli
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410424/
https://www.ncbi.nlm.nih.gov/pubmed/22801783
http://dx.doi.org/10.1083/jcb.201204008
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