MDC1 is required for the intra-S-phase DNA damage checkpoint

Goldberg, M., Stucki, M., Falck, J., D'Amours, D., Rahman, D., Pappin, D., Bartek, J., Jackson, S. P. (February 2003) MDC1 is required for the intra-S-phase DNA damage checkpoint. Nature, 421 (6926). pp. 952-6. ISSN 0028-0836 (Print)0028-0836 (Linking)

URL: http://www.ncbi.nlm.nih.gov/pubmed/12607003
DOI: 10.1038/nature01445

Abstract

MRE11, RAD50 and NBS1 form a highly conserved protein complex (the MRE11 complex) that is involved in the detection, signalling and repair of DNA damage. We identify MDC1 (KIAA0170/NFBD1), a protein that contains a forkhead-associated (FHA) domain and two BRCA1 carboxy-terminal (BRCT) domains, as a binding partner for the MRE11 complex. We show that, in response to ionizing radiation, MDC1 is hyperphosphorylated in an ATM-dependent manner, and rapidly relocalizes to nuclear foci that also contain the MRE11 complex, phosphorylated histone H2AX and 53BP1. Downregulation of MDC1 expression by small interfering RNA yields a radio-resistant DNA synthesis (RDS) phenotype and prevents ionizing radiation-induced focus formation by the MRE11 complex. However, downregulation of MDC1 does not abolish the ionizing radiation-induced phosphorylation of NBS1, CHK2 and SMC1, or the degradation of CDC25A. Furthermore, we show that overexpression of the MDC1 FHA domain interferes with focus formation by MDC1 itself and by the MRE11 complex, and induces an RDS phenotype. These findings reveal that MDC1-mediated focus formation by the MRE11 complex at sites of DNA damage is crucial for the efficient activation of the intra-S-phase checkpoint.

Item Type: Paper
Uncontrolled Keywords: Animals Cell Cycle Proteins/metabolism Cell Line Chromosomal Proteins, Non-Histone/metabolism DNA Damage/radiation effects DNA Repair Enzymes DNA-Binding Proteins/chemistry/ metabolism Humans Mice Nuclear Proteins/chemistry/ metabolism Phosphorylation/radiation effects Protein Kinases/metabolism Protein Structure, Tertiary Protein-Serine-Threonine Kinases Radiation, Ionizing S Phase/radiation effects Trans-Activators/chemistry/ metabolism Tumor Cells, Cultured cdc25 Phosphatases/metabolism
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromosome
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromosomes, structure and function > chromosome

bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > kinase
CSHL Authors:
Communities: CSHL labs > Pappin lab
Depositing User: Matt Covey
Date: 27 February 2003
Date Deposited: 01 Jul 2013 16:01
Last Modified: 01 Jul 2013 16:01
Related URLs:
URI: http://repository.cshl.edu/id/eprint/27890

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