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Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins
The Retinoblastoma (RB) transcriptional corepressor and related family of pocket proteins play central roles in cell cycle control and development, and the regulatory networks governed by these factors are frequently inactivated during tumorigenesis. During normal growth, these proteins are subject...
Autores principales: | , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The American Society for Cell Biology
2010
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2982090/ https://www.ncbi.nlm.nih.gov/pubmed/20861300 http://dx.doi.org/10.1091/mbc.E10-06-0520 |
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author | Acharya, Pankaj Raj, Nitin Buckley, Martin S. Zhang, Liang Duperon, Stephanie Williams, Geoffrey Henry, R. William Arnosti, David N. |
author_facet | Acharya, Pankaj Raj, Nitin Buckley, Martin S. Zhang, Liang Duperon, Stephanie Williams, Geoffrey Henry, R. William Arnosti, David N. |
author_sort | Acharya, Pankaj |
collection | PubMed |
description | The Retinoblastoma (RB) transcriptional corepressor and related family of pocket proteins play central roles in cell cycle control and development, and the regulatory networks governed by these factors are frequently inactivated during tumorigenesis. During normal growth, these proteins are subject to tight control through at least two mechanisms. First, during cell cycle progression, repressor potential is down-regulated by Cdk-dependent phosphorylation, resulting in repressor dissociation from E2F family transcription factors. Second, RB proteins are subject to proteasome-mediated destruction during development. To better understand the mechanism for RB family protein instability, we characterized Rbf1 turnover in Drosophila and the protein motifs required for its destabilization. We show that specific point mutations in a conserved C-terminal instability element strongly stabilize Rbf1, but strikingly, these mutations also cripple repression activity. Rbf1 is destabilized specifically in actively proliferating tissues of the larva, indicating that controlled degradation of Rbf1 is linked to developmental signals. The positive linkage between Rbf1 activity and its destruction indicates that repressor function is governed in a manner similar to that described by the degron theory of transcriptional activation. Analogous mutations in the mammalian RB family member p107 similarly induce abnormal accumulation, indicating substantial conservation of this regulatory pathway. |
format | Text |
id | pubmed-2982090 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | The American Society for Cell Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-29820902011-01-30 Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins Acharya, Pankaj Raj, Nitin Buckley, Martin S. Zhang, Liang Duperon, Stephanie Williams, Geoffrey Henry, R. William Arnosti, David N. Mol Biol Cell Articles The Retinoblastoma (RB) transcriptional corepressor and related family of pocket proteins play central roles in cell cycle control and development, and the regulatory networks governed by these factors are frequently inactivated during tumorigenesis. During normal growth, these proteins are subject to tight control through at least two mechanisms. First, during cell cycle progression, repressor potential is down-regulated by Cdk-dependent phosphorylation, resulting in repressor dissociation from E2F family transcription factors. Second, RB proteins are subject to proteasome-mediated destruction during development. To better understand the mechanism for RB family protein instability, we characterized Rbf1 turnover in Drosophila and the protein motifs required for its destabilization. We show that specific point mutations in a conserved C-terminal instability element strongly stabilize Rbf1, but strikingly, these mutations also cripple repression activity. Rbf1 is destabilized specifically in actively proliferating tissues of the larva, indicating that controlled degradation of Rbf1 is linked to developmental signals. The positive linkage between Rbf1 activity and its destruction indicates that repressor function is governed in a manner similar to that described by the degron theory of transcriptional activation. Analogous mutations in the mammalian RB family member p107 similarly induce abnormal accumulation, indicating substantial conservation of this regulatory pathway. The American Society for Cell Biology 2010-11-15 /pmc/articles/PMC2982090/ /pubmed/20861300 http://dx.doi.org/10.1091/mbc.E10-06-0520 Text en © 2010 by The American Society for Cell Biology 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). |
spellingShingle | Articles Acharya, Pankaj Raj, Nitin Buckley, Martin S. Zhang, Liang Duperon, Stephanie Williams, Geoffrey Henry, R. William Arnosti, David N. Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins |
title | Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins |
title_full | Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins |
title_fullStr | Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins |
title_full_unstemmed | Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins |
title_short | Paradoxical Instability–Activity Relationship Defines a Novel Regulatory Pathway for Retinoblastoma Proteins |
title_sort | paradoxical instability–activity relationship defines a novel regulatory pathway for retinoblastoma proteins |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2982090/ https://www.ncbi.nlm.nih.gov/pubmed/20861300 http://dx.doi.org/10.1091/mbc.E10-06-0520 |
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