BubR1 is involved in regulation of DNA damage responses

• Published in: Oncogene Vol. 25; no. 25; pp. 3598 - 3605
• Main Authors: FANG, Y, LIU, T, WANG, X, YANG, Y.-M, DENG, H, KUNICKI, J, TRAGANOS, F, DARZYNKIEWICZ, Z, LU, L, DAI, W
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing 15.06.2006; Nature Publishing Group
• Subjects: Animals; Antibiotics, Antineoplastic - toxicity; Biological and medical sciences; Blotting, Western; BUBR1 protein; Cell Cycle Proteins; Cell cycle, cell proliferation; Cell Line; Cell lines; Cell physiology; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Cyclin-dependent kinase inhibitor p21; Deoxyribonucleic acid; DNA; DNA damage; DNA Damage - physiology; DNA Repair - physiology; Doxorubicin; Doxorubicin - toxicity; Fibroblasts - drug effects; Flow Cytometry; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Gene expression; Genetics; Genomic instability; Genomics; HeLa Cells; Histone H2A; Histones - metabolism; Humans; Immunoprecipitation; Mass Spectrometry; Mass spectroscopy; Mice; Mitosis; Mitosis - drug effects; Mitosis - physiology; Molecular and cellular biology; Molecular Sequence Data; Oncology; p53 Protein; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose); Poly(ADP-ribose) polymerase; Poly(ADP-ribose) Polymerases - metabolism; Protein Kinases - genetics; Protein Kinases - metabolism; Protein-Serine-Threonine Kinases; rho GTP-Binding Proteins - metabolism; Ribose; RNA Interference; RNA-mediated interference; Rodents; Signal Transduction - physiology; Spindles; Transfection; Tumor Suppressor Protein p53 - metabolism; Tumorigenesis; Tumors; Yeast; Regulation(control); TP53 Gene; BuhR1: DNA damage: checkpoint: p53; DNA; Cell cycle; CDKN1A Gene; PARP; Lesion; Carcinogenesis; Control point; p21; Tumor suppressor gene
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/sj.onc.1209392

Defective mitotic spindles or an impaired spindle-kinetochore interaction activates the spindle checkpoint. We have previously shown that BubR1 haplo-insufficiency results in enhanced genomic instability and tumorigenesis in mice. Here we report that BubR1 deficiency also leads to a compromised response to DNA damage. Following treatment with doxorubicin, BubR1(+/-) murine fibroblast cells (MEF) were defective in undergoing G(2)/M arrest. Thus, whereas in the presence of DNA damage BubR1(+/+) MEF cells remained arrested in mitosis, BubR1(+/-) MEFs rapidly exited from mitosis and divided. The impaired mitotic arrest of BubR1(+/-) MEFs was associated with low levels of phospho-histone H2AX, p53, and p21 after DNA damage caused by treatment with both doxorubicin and ultraviolet light (UV). The impaired expression of p53 and p21 was also confirmed in human cell lines with BubR1 knockdown via RNA interference. Affinity pull-down coupled with mass spectrometry identified Poly(ADP-ribose) polymerase 1 (PARP-1) as one of the proteins interacting with BubR1. Reciprocal co-immunoprecipitation analysis confirmed the physical interaction between BubR1 and PARP-1. Our further study revealed that the ability of retaining intact PARP-1 or its cleavage product p89 was compromised in BubR1(+/-) MEFs upon treatment with doxorubicin or UV. Given that PARP-1 mediates DNA damage responses and regulates the activity of p53, our studies suggest that there exists a cross-talk between the spindle checkpoint and the DNA damage checkpoint and that BubR1 may play an important role in mediating the cross-talk.