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A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization

PDZK1 and ezrin, radixin, moesin binding phosphoprotein 50 kDa (EBP50) are postsynaptic density 95/disc-large/zona occludens (PDZ)-domain–containing scaffolding proteins found in the apical microvilli of polarized epithelial cells. Binary interactions have been shown between the tail of PDZK1 and th...

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Detalles Bibliográficos
Autores principales: LaLonde, David P., Garbett, Damien, Bretscher, Anthony
Formato: Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861611/
https://www.ncbi.nlm.nih.gov/pubmed/20237154
http://dx.doi.org/10.1091/mbc.E10-01-0008
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author LaLonde, David P.
Garbett, Damien
Bretscher, Anthony
author_facet LaLonde, David P.
Garbett, Damien
Bretscher, Anthony
author_sort LaLonde, David P.
collection PubMed
description PDZK1 and ezrin, radixin, moesin binding phosphoprotein 50 kDa (EBP50) are postsynaptic density 95/disc-large/zona occludens (PDZ)-domain–containing scaffolding proteins found in the apical microvilli of polarized epithelial cells. Binary interactions have been shown between the tail of PDZK1 and the PDZ domains of EBP50, as well as between EBP50 and the membrane–cytoskeletal linking protein ezrin. Here, we show that these molecules form a regulated ternary complex in vitro and in vivo. Complex formation is cooperative because ezrin positively influences the PDZK1/EBP50 interaction. Moreover, the interaction of PDZK1 with EBP50 is enhanced by the occupancy of EBP50's adjacent PDZ domain. The complex is further regulated by location, because PDZK1 shuttles from the nucleus in low confluence cells to microvilli in high confluence cells, and this regulates the formation of the PDZK1/EBP50/ezrin complex in vivo. Knockdown of EBP50 decreases the presence of microvilli, a phenotype that can be rescued by EBP50 re-expression or expression of a PDZK1 chimera that is directly targeted to ezrin. Thus, when appropriately located, PDZK1 can provide a function necessary for microvilli formation normally provided by EBP50. By entering into the ternary complex, PDZK1 can both enhance the scaffolding at the apical membrane as well as augment EBP50's role in microvilli formation.
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spelling pubmed-28616112010-07-16 A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization LaLonde, David P. Garbett, Damien Bretscher, Anthony Mol Biol Cell Articles PDZK1 and ezrin, radixin, moesin binding phosphoprotein 50 kDa (EBP50) are postsynaptic density 95/disc-large/zona occludens (PDZ)-domain–containing scaffolding proteins found in the apical microvilli of polarized epithelial cells. Binary interactions have been shown between the tail of PDZK1 and the PDZ domains of EBP50, as well as between EBP50 and the membrane–cytoskeletal linking protein ezrin. Here, we show that these molecules form a regulated ternary complex in vitro and in vivo. Complex formation is cooperative because ezrin positively influences the PDZK1/EBP50 interaction. Moreover, the interaction of PDZK1 with EBP50 is enhanced by the occupancy of EBP50's adjacent PDZ domain. The complex is further regulated by location, because PDZK1 shuttles from the nucleus in low confluence cells to microvilli in high confluence cells, and this regulates the formation of the PDZK1/EBP50/ezrin complex in vivo. Knockdown of EBP50 decreases the presence of microvilli, a phenotype that can be rescued by EBP50 re-expression or expression of a PDZK1 chimera that is directly targeted to ezrin. Thus, when appropriately located, PDZK1 can provide a function necessary for microvilli formation normally provided by EBP50. By entering into the ternary complex, PDZK1 can both enhance the scaffolding at the apical membrane as well as augment EBP50's role in microvilli formation. The American Society for Cell Biology 2010-05-01 /pmc/articles/PMC2861611/ /pubmed/20237154 http://dx.doi.org/10.1091/mbc.E10-01-0008 Text en © 2010 by The American Society for Cell Biology
spellingShingle Articles
LaLonde, David P.
Garbett, Damien
Bretscher, Anthony
A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization
title A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization
title_full A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization
title_fullStr A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization
title_full_unstemmed A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization
title_short A Regulated Complex of the Scaffolding Proteins PDZK1 and EBP50 with Ezrin Contribute to Microvillar Organization
title_sort regulated complex of the scaffolding proteins pdzk1 and ebp50 with ezrin contribute to microvillar organization
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861611/
https://www.ncbi.nlm.nih.gov/pubmed/20237154
http://dx.doi.org/10.1091/mbc.E10-01-0008
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