Cargando…
CtIP-mediated resection is essential for viability and can operate independently of BRCA1
Homologous recombination (HR) is initiated by DNA end resection, a process in which stretches of single-strand DNA (ssDNA) are generated and used for homology search. Factors implicated in resection include nucleases MRE11, EXO1, and DNA2, which process DNA ends into 3′ ssDNA overhangs; helicases su...
Autores principales: | , , , , , , , , , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
2014
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4042650/ https://www.ncbi.nlm.nih.gov/pubmed/24842372 http://dx.doi.org/10.1084/jem.20131939 |
_version_ | 1782318848415891456 |
---|---|
author | Polato, Federica Callen, Elsa Wong, Nancy Faryabi, Robert Bunting, Samuel Chen, Hua-Tang Kozak, Marina Kruhlak, Michael J. Reczek, Colleen R. Lee, Wen-Hwa Ludwig, Thomas Baer, Richard Feigenbaum, Lionel Jackson, Stephen Nussenzweig, André |
author_facet | Polato, Federica Callen, Elsa Wong, Nancy Faryabi, Robert Bunting, Samuel Chen, Hua-Tang Kozak, Marina Kruhlak, Michael J. Reczek, Colleen R. Lee, Wen-Hwa Ludwig, Thomas Baer, Richard Feigenbaum, Lionel Jackson, Stephen Nussenzweig, André |
author_sort | Polato, Federica |
collection | PubMed |
description | Homologous recombination (HR) is initiated by DNA end resection, a process in which stretches of single-strand DNA (ssDNA) are generated and used for homology search. Factors implicated in resection include nucleases MRE11, EXO1, and DNA2, which process DNA ends into 3′ ssDNA overhangs; helicases such as BLM, which unwind DNA; and other proteins such as BRCA1 and CtIP whose functions remain unclear. CDK-mediated phosphorylation of CtIP on T847 is required to promote resection, whereas CDK-dependent phosphorylation of CtIP-S327 is required for interaction with BRCA1. Here, we provide evidence that CtIP functions independently of BRCA1 in promoting DSB end resection. First, using mouse models expressing S327A or T847A mutant CtIP as a sole species, and B cells deficient in CtIP, we show that loss of the CtIP-BRCA1 interaction does not detectably affect resection, maintenance of genomic stability or viability, whereas T847 is essential for these functions. Second, although loss of 53BP1 rescues the embryonic lethality and HR defects in BRCA1-deficient mice, it does not restore viability or genome integrity in CtIP(−/−) mice. Third, the increased resection afforded by loss of 53BP1 and the rescue of BRCA1-deficiency depend on CtIP but not EXO1. Finally, the sensitivity of BRCA1-deficient cells to poly ADP ribose polymerase (PARP) inhibition is partially rescued by the phospho-mimicking mutant CtIP (CtIP-T847E). Thus, in contrast to BRCA1, CtIP has indispensable roles in promoting resection and embryonic development. |
format | Online Article Text |
id | pubmed-4042650 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-40426502014-12-02 CtIP-mediated resection is essential for viability and can operate independently of BRCA1 Polato, Federica Callen, Elsa Wong, Nancy Faryabi, Robert Bunting, Samuel Chen, Hua-Tang Kozak, Marina Kruhlak, Michael J. Reczek, Colleen R. Lee, Wen-Hwa Ludwig, Thomas Baer, Richard Feigenbaum, Lionel Jackson, Stephen Nussenzweig, André J Exp Med Brief Definitive Report Homologous recombination (HR) is initiated by DNA end resection, a process in which stretches of single-strand DNA (ssDNA) are generated and used for homology search. Factors implicated in resection include nucleases MRE11, EXO1, and DNA2, which process DNA ends into 3′ ssDNA overhangs; helicases such as BLM, which unwind DNA; and other proteins such as BRCA1 and CtIP whose functions remain unclear. CDK-mediated phosphorylation of CtIP on T847 is required to promote resection, whereas CDK-dependent phosphorylation of CtIP-S327 is required for interaction with BRCA1. Here, we provide evidence that CtIP functions independently of BRCA1 in promoting DSB end resection. First, using mouse models expressing S327A or T847A mutant CtIP as a sole species, and B cells deficient in CtIP, we show that loss of the CtIP-BRCA1 interaction does not detectably affect resection, maintenance of genomic stability or viability, whereas T847 is essential for these functions. Second, although loss of 53BP1 rescues the embryonic lethality and HR defects in BRCA1-deficient mice, it does not restore viability or genome integrity in CtIP(−/−) mice. Third, the increased resection afforded by loss of 53BP1 and the rescue of BRCA1-deficiency depend on CtIP but not EXO1. Finally, the sensitivity of BRCA1-deficient cells to poly ADP ribose polymerase (PARP) inhibition is partially rescued by the phospho-mimicking mutant CtIP (CtIP-T847E). Thus, in contrast to BRCA1, CtIP has indispensable roles in promoting resection and embryonic development. The Rockefeller University Press 2014-06-02 /pmc/articles/PMC4042650/ /pubmed/24842372 http://dx.doi.org/10.1084/jem.20131939 Text en 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 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/). |
spellingShingle | Brief Definitive Report Polato, Federica Callen, Elsa Wong, Nancy Faryabi, Robert Bunting, Samuel Chen, Hua-Tang Kozak, Marina Kruhlak, Michael J. Reczek, Colleen R. Lee, Wen-Hwa Ludwig, Thomas Baer, Richard Feigenbaum, Lionel Jackson, Stephen Nussenzweig, André CtIP-mediated resection is essential for viability and can operate independently of BRCA1 |
title | CtIP-mediated resection is essential for viability and can operate independently of BRCA1 |
title_full | CtIP-mediated resection is essential for viability and can operate independently of BRCA1 |
title_fullStr | CtIP-mediated resection is essential for viability and can operate independently of BRCA1 |
title_full_unstemmed | CtIP-mediated resection is essential for viability and can operate independently of BRCA1 |
title_short | CtIP-mediated resection is essential for viability and can operate independently of BRCA1 |
title_sort | ctip-mediated resection is essential for viability and can operate independently of brca1 |
topic | Brief Definitive Report |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4042650/ https://www.ncbi.nlm.nih.gov/pubmed/24842372 http://dx.doi.org/10.1084/jem.20131939 |
work_keys_str_mv | AT polatofederica ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT callenelsa ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT wongnancy ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT faryabirobert ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT buntingsamuel ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT chenhuatang ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT kozakmarina ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT kruhlakmichaelj ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT reczekcolleenr ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT leewenhwa ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT ludwigthomas ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT baerrichard ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT feigenbaumlionel ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT jacksonstephen ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 AT nussenzweigandre ctipmediatedresectionisessentialforviabilityandcanoperateindependentlyofbrca1 |