1. Replication stress induces 53BP1-containing OPT domains in G1 cells
- Author
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Daniela S. Dimitrova, Rimma Belotserkovskaya, Stephen P. Jackson, Peter Fraser, Charles R. Bradshaw, Sophie E. Polo, Jeanine A. Harrigan, and Julia Coates
- Subjects
Aphidicolin ,DNA Replication ,Transcription, Genetic ,DNA damage ,Biology ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Control of chromosome duplication ,Humans ,Research Articles ,Cells, Cultured ,030304 developmental biology ,0303 health sciences ,Chromosomal fragile site ,DNA replication ,G1 Phase ,Intracellular Signaling Peptides and Proteins ,Cell Biology ,G2-M DNA damage checkpoint ,Molecular biology ,3. Good health ,chemistry ,030220 oncology & carcinogenesis ,Origin recognition complex ,Tumor Suppressor p53-Binding Protein 1 ,Chromatin immunoprecipitation ,Octamer Transcription Factor-1 ,Transcription Factors - Abstract
53BP1-OPT domains, nuclear bodies that arise in G1 cells at sites of DNA damage induced by incomplete DNA replication, preferentially localize to chromosomal common fragile sites., Chromosomal deletions and rearrangements in tumors are often associated with common fragile sites, which are specific genomic loci prone to gaps and breaks in metaphase chromosomes. Common fragile sites appear to arise through incomplete DNA replication because they are induced after partial replication inhibition by agents such as aphidicolin. Here, we show that in G1 cells, large nuclear bodies arise that contain p53 binding protein 1 (53BP1), phosphorylated H2AX (γH2AX), and mediator of DNA damage checkpoint 1 (MDC1), as well as components of previously characterized OPT (Oct-1, PTF, transcription) domains. Notably, we find that incubating cells with low aphidicolin doses increases the incidence and number of 53BP1-OPT domains in G1 cells, and by chromatin immunoprecipitation and massively parallel sequencing analysis of γH2AX, we demonstrate that OPT domains are enriched at common fragile sites. These findings invoke a model wherein incomplete DNA synthesis during S phase leads to a DNA damage response and formation of 53BP1-OPT domains in the subsequent G1.
- Published
- 2011