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The PI3K/Akt1 pathway enhances steady-state levels of FANCL

Fanconi anemia hematopoietic stem cells display poor self-renewal capacity when subjected to a variety of cellular stress. This phenotype raises the question of whether the Fanconi anemia proteins are stabilized or recruited as part of a stress response and protect against stem cell loss. Here we pr...

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Autores principales: Dao, Kim-Hien T., Rotelli, Michael D., Brown, Brieanna R., Yates, Jane E., Rantala, Juha, Tognon, Cristina, Tyner, Jeffrey W., Druker, Brian J., Bagby, Grover C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3744951/
https://www.ncbi.nlm.nih.gov/pubmed/23783032
http://dx.doi.org/10.1091/mbc.E13-03-0144
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author Dao, Kim-Hien T.
Rotelli, Michael D.
Brown, Brieanna R.
Yates, Jane E.
Rantala, Juha
Tognon, Cristina
Tyner, Jeffrey W.
Druker, Brian J.
Bagby, Grover C.
author_facet Dao, Kim-Hien T.
Rotelli, Michael D.
Brown, Brieanna R.
Yates, Jane E.
Rantala, Juha
Tognon, Cristina
Tyner, Jeffrey W.
Druker, Brian J.
Bagby, Grover C.
author_sort Dao, Kim-Hien T.
collection PubMed
description Fanconi anemia hematopoietic stem cells display poor self-renewal capacity when subjected to a variety of cellular stress. This phenotype raises the question of whether the Fanconi anemia proteins are stabilized or recruited as part of a stress response and protect against stem cell loss. Here we provide evidence that FANCL, the E3 ubiquitin ligase of the Fanconi anemia pathway, is constitutively targeted for degradation by the proteasome. We confirm biochemically that FANCL is polyubiquitinated with Lys-48–linked chains. Evaluation of a series of N-terminal–deletion mutants showed that FANCL's E2-like fold may direct ubiquitination. In addition, our studies showed that FANCL is stabilized in a complex with axin1 when glycogen synthase kinase-3β is overexpressed. This result leads us to investigate the potential regulation of FANCL by upstream signaling pathways known to regulate glycogen synthase kinase-3β. We report that constitutively active, myristoylated-Akt increases FANCL protein level by reducing polyubiquitination of FANCL. Two-dimensional PAGE analysis shows that acidic forms of FANCL, some of which are phospho-FANCL, are not subject to polyubiquitination. These results indicate that a signal transduction pathway involved in self-renewal and survival of hematopoietic stem cells also functions to stabilize FANCL and suggests that FANCL participates directly in support of stem cell function.
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spelling pubmed-37449512013-10-30 The PI3K/Akt1 pathway enhances steady-state levels of FANCL Dao, Kim-Hien T. Rotelli, Michael D. Brown, Brieanna R. Yates, Jane E. Rantala, Juha Tognon, Cristina Tyner, Jeffrey W. Druker, Brian J. Bagby, Grover C. Mol Biol Cell Articles Fanconi anemia hematopoietic stem cells display poor self-renewal capacity when subjected to a variety of cellular stress. This phenotype raises the question of whether the Fanconi anemia proteins are stabilized or recruited as part of a stress response and protect against stem cell loss. Here we provide evidence that FANCL, the E3 ubiquitin ligase of the Fanconi anemia pathway, is constitutively targeted for degradation by the proteasome. We confirm biochemically that FANCL is polyubiquitinated with Lys-48–linked chains. Evaluation of a series of N-terminal–deletion mutants showed that FANCL's E2-like fold may direct ubiquitination. In addition, our studies showed that FANCL is stabilized in a complex with axin1 when glycogen synthase kinase-3β is overexpressed. This result leads us to investigate the potential regulation of FANCL by upstream signaling pathways known to regulate glycogen synthase kinase-3β. We report that constitutively active, myristoylated-Akt increases FANCL protein level by reducing polyubiquitination of FANCL. Two-dimensional PAGE analysis shows that acidic forms of FANCL, some of which are phospho-FANCL, are not subject to polyubiquitination. These results indicate that a signal transduction pathway involved in self-renewal and survival of hematopoietic stem cells also functions to stabilize FANCL and suggests that FANCL participates directly in support of stem cell function. The American Society for Cell Biology 2013-08-15 /pmc/articles/PMC3744951/ /pubmed/23783032 http://dx.doi.org/10.1091/mbc.E13-03-0144 Text en © 2013 Dao et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell Biology.
spellingShingle Articles
Dao, Kim-Hien T.
Rotelli, Michael D.
Brown, Brieanna R.
Yates, Jane E.
Rantala, Juha
Tognon, Cristina
Tyner, Jeffrey W.
Druker, Brian J.
Bagby, Grover C.
The PI3K/Akt1 pathway enhances steady-state levels of FANCL
title The PI3K/Akt1 pathway enhances steady-state levels of FANCL
title_full The PI3K/Akt1 pathway enhances steady-state levels of FANCL
title_fullStr The PI3K/Akt1 pathway enhances steady-state levels of FANCL
title_full_unstemmed The PI3K/Akt1 pathway enhances steady-state levels of FANCL
title_short The PI3K/Akt1 pathway enhances steady-state levels of FANCL
title_sort pi3k/akt1 pathway enhances steady-state levels of fancl
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3744951/
https://www.ncbi.nlm.nih.gov/pubmed/23783032
http://dx.doi.org/10.1091/mbc.E13-03-0144
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