Inherited disorders resulting from defective responses to DNA double strand breaks feature immunodeficiency, bone marrow failure, lymphoid malignancies and developmental delay. Cellular responses to double strand breaks require rapid communication between specialized DNA damage recognition complexes and the core cell cycle machinery, but this important relationship is poorly understood. In the previous project period we identified an unanticipated protein interaction that provides a unique opportunity to make major strides in understanding this relationship. The interaction involves Mre11, a core component of the DNA damage recognition machinery that is mutated in ataxia-telangiectasia like disorders (ATLD), and cyclin dependent kinase 2 (CDK2), a core component of the cell cycle machinery. We reported that the interaction facilitates CDK2 dependent phosphorylation of a single substrate, demonstrating for the first time that Mre11 has roles in the normal cell cycle. In this proposal we present preliminary evidence that Mre11 controls CDK2 functions more globally during the normal cell cycle. Our findings indicate that this control plays an important role when cells undergo DNA damage. Therefore, we will test the overarching hypothesis that Mre11 interacts with and controls CDK2 to provide a rapid switch between the normal cell cycle and the DNA damage response. We will determine roles that Mre11-CDK2 interaction plays is diverse biological contexts such as specialized recombination in lymphocyte development, and S phase checkpoint responses more generally. The studies proposed herein take advantage of murine systems with alleles of Mre11 that we constructed in the previous two project periods, along with new mouse models we will develop to directly test our hypotheses. The combination of our long term investment in the development of unique biological reagents and our discovery of Mre11-CDK2 interaction places the Principle Investigator's laboratory in a unique position to make major strides in our understanding of cellular responses to DNA damage and their associated diseases.
The DNA of our cells frequently suffers from breaks to both strands of the Watson-Crick double helix. Such damage is called double strand breaks, and individuals who are defective in repairing this damage suffer from immune deficiencies, bone marrow failure, leukemias/lymphomas, and other diseases. This proposal aims to significantly increase our understanding of how cells respond to the presence of double strand breaks, with the hope of gaining greater understanding of why inherited deficiencies are so devastating. Because the general population also suffers from similar ailments at later ages, understanding these inherited disorders may present new therapeutic opportunities that are not uncovered by other avenues of investigation.
| Hartlerode, Andrea J; Regal, Joshua A; Ferguson, David O (2018) Reversible mislocalization of a disease-associated MRE11 splice variant product. Sci Rep 8:10121 |
| Spehalski, Elizabeth; Capper, Kayla M; Smith, Cheryl J et al. (2017) MRE11 Promotes Tumorigenesis by Facilitating Resistance to Oncogene-Induced Replication Stress. Cancer Res 77:5327-5338 |
| Hartlerode, Andrea J; Morgan, Mary J; Wu, Yipin et al. (2015) Recruitment and activation of the ATM kinase in the absence of DNA-damage sensors. Nat Struct Mol Biol 22:736-43 |
| Jones, Morgan; Osawa, Gail; Regal, Joshua A et al. (2014) Hematopoietic stem cells are acutely sensitive to Acd shelterin gene inactivation. J Clin Invest 124:353-66 |
| Regal, Joshua A; Festerling, Todd A; Buis, Jeffrey M et al. (2013) Disease-associated MRE11 mutants impact ATM/ATR DNA damage signaling by distinct mechanisms. Hum Mol Genet 22:5146-59 |
| Guilherme, Rafael F; Xisto, Debora G; Kunkel, Steven L et al. (2013) Pulmonary antifibrotic mechanisms aspirin-triggered lipoxin A(4) synthetic analog. Am J Respir Cell Mol Biol 49:1029-37 |
| Spehalski, Elizabeth; Kovalchuk, Alexander L; Collins, John T et al. (2012) Oncogenic Myc translocations are independent of chromosomal location and orientation of the immunoglobulin heavy chain locus. Proc Natl Acad Sci U S A 109:13728-32 |
| Buis, Jeffrey; Stoneham, Trina; Spehalski, Elizabeth et al. (2012) Mre11 regulates CtIP-dependent double-strand break repair by interaction with CDK2. Nat Struct Mol Biol 19:246-52 |
| Yu, Zhenbao; Vogel, Gillian; Coulombe, Yan et al. (2012) The MRE11 GAR motif regulates DNA double-strand break processing and ATR activation. Cell Res 22:305-20 |
| Deng, Yibin; Guo, Xiaolan; Ferguson, David O et al. (2009) Multiple roles for MRE11 at uncapped telomeres. Nature 460:914-8 |
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