MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells

Transcytosis is used alone (e.g., hepatoma HepG2 cells) or in combination with a direct pathway from the Golgi (e.g., epithelial MDCK cells) as an indirect route for targeting proteins to the apical surface. The raft-associated MAL protein is an essential element of the machinery for the direct rout...

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Autores principales: de Marco, María C., Martín-Belmonte, Fernando, Kremer, Leonor, Albar, Juan P., Correas, Isabel, Vaerman, Jean P., Marazuela, Mónica, Byrne, Jennifer A., Alonso, Miguel A.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2002
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2173496/
https://www.ncbi.nlm.nih.gov/pubmed/12370246
http://dx.doi.org/10.1083/jcb.200206033
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author de Marco, María C.
Martín-Belmonte, Fernando
Kremer, Leonor
Albar, Juan P.
Correas, Isabel
Vaerman, Jean P.
Marazuela, Mónica
Byrne, Jennifer A.
Alonso, Miguel A.
author_facet de Marco, María C.
Martín-Belmonte, Fernando
Kremer, Leonor
Albar, Juan P.
Correas, Isabel
Vaerman, Jean P.
Marazuela, Mónica
Byrne, Jennifer A.
Alonso, Miguel A.
author_sort de Marco, María C.
collection PubMed
description Transcytosis is used alone (e.g., hepatoma HepG2 cells) or in combination with a direct pathway from the Golgi (e.g., epithelial MDCK cells) as an indirect route for targeting proteins to the apical surface. The raft-associated MAL protein is an essential element of the machinery for the direct route in MDCK cells. Herein, we present the functional characterization of MAL2, a member of the MAL protein family, in polarized HepG2 cells. MAL2 resided selectively in rafts and is predominantly distributed in a compartment localized beneath the subapical F-actin cytoskeleton. MAL2 greatly colocalized in subapical endosome structures with transcytosing molecules en route to the apical surface. Depletion of endogenous MAL2 drastically blocked transcytotic transport of exogenous polymeric immunoglobulin receptor and endogenous glycosylphosphatidylinositol-anchored protein CD59 to the apical membrane. MAL2 depletion did not affect the internalization of these molecules but produced their accumulation in perinuclear endosome elements that were accessible to transferrin. Normal transcytosis persisted in cells that expressed exogenous MAL2 designed to resist the depletion treatment. MAL2 is therefore essential for transcytosis in HepG2 cells.
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spelling pubmed-21734962008-05-01 MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells de Marco, María C. Martín-Belmonte, Fernando Kremer, Leonor Albar, Juan P. Correas, Isabel Vaerman, Jean P. Marazuela, Mónica Byrne, Jennifer A. Alonso, Miguel A. J Cell Biol Report Transcytosis is used alone (e.g., hepatoma HepG2 cells) or in combination with a direct pathway from the Golgi (e.g., epithelial MDCK cells) as an indirect route for targeting proteins to the apical surface. The raft-associated MAL protein is an essential element of the machinery for the direct route in MDCK cells. Herein, we present the functional characterization of MAL2, a member of the MAL protein family, in polarized HepG2 cells. MAL2 resided selectively in rafts and is predominantly distributed in a compartment localized beneath the subapical F-actin cytoskeleton. MAL2 greatly colocalized in subapical endosome structures with transcytosing molecules en route to the apical surface. Depletion of endogenous MAL2 drastically blocked transcytotic transport of exogenous polymeric immunoglobulin receptor and endogenous glycosylphosphatidylinositol-anchored protein CD59 to the apical membrane. MAL2 depletion did not affect the internalization of these molecules but produced their accumulation in perinuclear endosome elements that were accessible to transferrin. Normal transcytosis persisted in cells that expressed exogenous MAL2 designed to resist the depletion treatment. MAL2 is therefore essential for transcytosis in HepG2 cells. The Rockefeller University Press 2002-10-14 /pmc/articles/PMC2173496/ /pubmed/12370246 http://dx.doi.org/10.1083/jcb.200206033 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 Report
de Marco, María C.
Martín-Belmonte, Fernando
Kremer, Leonor
Albar, Juan P.
Correas, Isabel
Vaerman, Jean P.
Marazuela, Mónica
Byrne, Jennifer A.
Alonso, Miguel A.
MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells
title MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells
title_full MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells
title_fullStr MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells
title_full_unstemmed MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells
title_short MAL2, a novel raft protein of the MAL family, is an essential component of the machinery for transcytosis in hepatoma HepG2 cells
title_sort mal2, a novel raft protein of the mal family, is an essential component of the machinery for transcytosis in hepatoma hepg2 cells
topic Report
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2173496/
https://www.ncbi.nlm.nih.gov/pubmed/12370246
http://dx.doi.org/10.1083/jcb.200206033
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