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The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors

Transport receptors of the importin β family continuously shuttle between the nucleus and cytoplasm. We previously reported that the nuclear export of importin β involves energy-requiring step(s) in living cells. Here, we show that the in vitro nuclear export of importin β also requires energy input...

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Autores principales: Kose, Shingo, Furuta, Maiko, Koike, Makiko, Yoneda, Yoshihiro, Imamoto, Naoko
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2005
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2171223/
https://www.ncbi.nlm.nih.gov/pubmed/16203861
http://dx.doi.org/10.1083/jcb.200506074
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author Kose, Shingo
Furuta, Maiko
Koike, Makiko
Yoneda, Yoshihiro
Imamoto, Naoko
author_facet Kose, Shingo
Furuta, Maiko
Koike, Makiko
Yoneda, Yoshihiro
Imamoto, Naoko
author_sort Kose, Shingo
collection PubMed
description Transport receptors of the importin β family continuously shuttle between the nucleus and cytoplasm. We previously reported that the nuclear export of importin β involves energy-requiring step(s) in living cells. Here, we show that the in vitro nuclear export of importin β also requires energy input. Cytosol, depleted of ATP-binding proteins, did not support the sufficient nuclear export of importin β. Further purification revealed that the active component in the absorbed fraction was a 70-kD heat shock cognate protein (hsc70). The addition of recombinant hsc70, but not an ATPase-deficient hsc70 mutant, to the depleted cytosol restored the export activity. In living cells, depletion of hsc70 caused the significant nuclear accumulation of importin β. These effects of hsc70 were observed in the nuclear export of importin β, but also for other import receptors, transportin and importin α. These results suggest that hsc70 broadly modulates nucleocytoplasmic transport systems by regulating the nuclear export of receptor proteins.
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spelling pubmed-21712232008-03-05 The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors Kose, Shingo Furuta, Maiko Koike, Makiko Yoneda, Yoshihiro Imamoto, Naoko J Cell Biol Research Articles Transport receptors of the importin β family continuously shuttle between the nucleus and cytoplasm. We previously reported that the nuclear export of importin β involves energy-requiring step(s) in living cells. Here, we show that the in vitro nuclear export of importin β also requires energy input. Cytosol, depleted of ATP-binding proteins, did not support the sufficient nuclear export of importin β. Further purification revealed that the active component in the absorbed fraction was a 70-kD heat shock cognate protein (hsc70). The addition of recombinant hsc70, but not an ATPase-deficient hsc70 mutant, to the depleted cytosol restored the export activity. In living cells, depletion of hsc70 caused the significant nuclear accumulation of importin β. These effects of hsc70 were observed in the nuclear export of importin β, but also for other import receptors, transportin and importin α. These results suggest that hsc70 broadly modulates nucleocytoplasmic transport systems by regulating the nuclear export of receptor proteins. The Rockefeller University Press 2005-10-10 /pmc/articles/PMC2171223/ /pubmed/16203861 http://dx.doi.org/10.1083/jcb.200506074 Text en Copyright © 2005, 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 Research Articles
Kose, Shingo
Furuta, Maiko
Koike, Makiko
Yoneda, Yoshihiro
Imamoto, Naoko
The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors
title The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors
title_full The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors
title_fullStr The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors
title_full_unstemmed The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors
title_short The 70-kD heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors
title_sort 70-kd heat shock cognate protein (hsc70) facilitates the nuclear export of the import receptors
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2171223/
https://www.ncbi.nlm.nih.gov/pubmed/16203861
http://dx.doi.org/10.1083/jcb.200506074
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