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Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain
MDC1 is a key mediator of the DNA-damage response in mammals with several phosphorylation-dependent protein interaction domains. The function of its N-terminal forkhead-associated (FHA) domain remains elusive. Here, we show with structural, biochemical and cellular data that the FHA domain mediates...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351156/ https://www.ncbi.nlm.nih.gov/pubmed/22234877 http://dx.doi.org/10.1093/nar/gkr1296 |
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author | Liu, Jinping Luo, Shukun Zhao, Hongchang Liao, Ji Li, Jing Yang, Chunying Xu, Bo Stern, David F. Xu, Xingzhi Ye, Keqiong |
author_facet | Liu, Jinping Luo, Shukun Zhao, Hongchang Liao, Ji Li, Jing Yang, Chunying Xu, Bo Stern, David F. Xu, Xingzhi Ye, Keqiong |
author_sort | Liu, Jinping |
collection | PubMed |
description | MDC1 is a key mediator of the DNA-damage response in mammals with several phosphorylation-dependent protein interaction domains. The function of its N-terminal forkhead-associated (FHA) domain remains elusive. Here, we show with structural, biochemical and cellular data that the FHA domain mediates phosphorylation-dependent dimerization of MDC1 in response to DNA damage. Crystal structures of the FHA domain reveal a face-to-face dimer with pseudo-dyad symmetry. We found that the FHA domain recognizes phosphothreonine 4 (pT4) at the N-terminus of MDC1 and determined its crystal structure in complex with a pT4 peptide. Biochemical analysis further revealed that in the dimer, the FHA domain binds in trans to pT4 from the other subunit, which greatly stabilizes the otherwise unstable dimer. We show that T4 is phosphorylated primarily by ATM upon DNA damage. MDC1 mutants with the FHA domain deleted or impaired in its ability to dimerize formed fewer foci at DNA-damage sites, but the localization defect was largely rescued by an artificial dimerization module, suggesting that dimerization is the primary function of the MDC1 FHA domain. Our results suggest a novel mechanism for the regulation of MDC1 function through T4 phosphorylation and FHA-mediated dimerization. |
format | Online Article Text |
id | pubmed-3351156 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-33511562012-05-14 Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain Liu, Jinping Luo, Shukun Zhao, Hongchang Liao, Ji Li, Jing Yang, Chunying Xu, Bo Stern, David F. Xu, Xingzhi Ye, Keqiong Nucleic Acids Res Genome Integrity, Repair and Replication MDC1 is a key mediator of the DNA-damage response in mammals with several phosphorylation-dependent protein interaction domains. The function of its N-terminal forkhead-associated (FHA) domain remains elusive. Here, we show with structural, biochemical and cellular data that the FHA domain mediates phosphorylation-dependent dimerization of MDC1 in response to DNA damage. Crystal structures of the FHA domain reveal a face-to-face dimer with pseudo-dyad symmetry. We found that the FHA domain recognizes phosphothreonine 4 (pT4) at the N-terminus of MDC1 and determined its crystal structure in complex with a pT4 peptide. Biochemical analysis further revealed that in the dimer, the FHA domain binds in trans to pT4 from the other subunit, which greatly stabilizes the otherwise unstable dimer. We show that T4 is phosphorylated primarily by ATM upon DNA damage. MDC1 mutants with the FHA domain deleted or impaired in its ability to dimerize formed fewer foci at DNA-damage sites, but the localization defect was largely rescued by an artificial dimerization module, suggesting that dimerization is the primary function of the MDC1 FHA domain. Our results suggest a novel mechanism for the regulation of MDC1 function through T4 phosphorylation and FHA-mediated dimerization. Oxford University Press 2012-05 2012-01-10 /pmc/articles/PMC3351156/ /pubmed/22234877 http://dx.doi.org/10.1093/nar/gkr1296 Text en © The Author(s) 2012. Published by Oxford University Press. http://creativecommons.org/licenses/by-nc/3.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Genome Integrity, Repair and Replication Liu, Jinping Luo, Shukun Zhao, Hongchang Liao, Ji Li, Jing Yang, Chunying Xu, Bo Stern, David F. Xu, Xingzhi Ye, Keqiong Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain |
title | Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain |
title_full | Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain |
title_fullStr | Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain |
title_full_unstemmed | Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain |
title_short | Structural mechanism of the phosphorylation-dependent dimerization of the MDC1 forkhead-associated domain |
title_sort | structural mechanism of the phosphorylation-dependent dimerization of the mdc1 forkhead-associated domain |
topic | Genome Integrity, Repair and Replication |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351156/ https://www.ncbi.nlm.nih.gov/pubmed/22234877 http://dx.doi.org/10.1093/nar/gkr1296 |
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