Billions of base pairs of DNA must be replicated trillions of times during a human lifetime. Adding to the difficulty, replication is challenged by stresses including DNA template lesions, difficult to replicate sequences, and conflicts with transcription. Cells employ multiple repair and signaling responses to replication stress depending on the type, persistence, and location of the problem. We have employed proteomic and genetic approaches to understand how cells overcome replication stress. These analyses identified several new replication stress response proteins including RADX. RADX binds single-stranded DNA and prevents replication fork cleavage by endonucleases. We hypothesize that it regulates the processes of replication fork reversal and fork protection through its single-stranded DNA binding activity. We will test this hypothesis and more generally characterize mechanisms that regulate fork reversal and protection using biochemical and genetic approaches. Since cancer cells have elevated levels of replication stress and many cancer therapeutics work by interfering with DNA replication, these studies will also generate discoveries that may be translated into the cancer clinic.
This application seeks to understand mechanisms of the replication stress response that stabilize forks and maintain genome stability. Failures in these mechanisms cause cancer and also determine the response of cancer cells to cancer therapies. Therefore, completing this project will provide insights into basic genome maintenance mechanisms with significant clinical application.
Mohni, Kareem N; Wessel, Sarah R; Zhao, Runxiang et al. (2018) HMCES Maintains Genome Integrity by Shielding Abasic Sites in Single-Strand DNA. Cell : |
Bhat, Kamakoti P; Krishnamoorthy, Archana; Dungrawala, Huzefa et al. (2018) RADX Modulates RAD51 Activity to Control Replication Fork Protection. Cell Rep 24:538-545 |
Carvajal-Maldonado, Denisse; Byrum, Andrea K; Jackson, Jessica et al. (2018) Perturbing cohesin dynamics drives MRE11 nuclease-dependent replication fork slowing. Nucleic Acids Res : |
Bhat, Kamakoti P; Cortez, David (2018) RPA and RAD51: fork reversal, fork protection, and genome stability. Nat Struct Mol Biol 25:446-453 |
Poole, Lisa A; Cortez, David (2017) Functions of SMARCAL1, ZRANB3, and HLTF in maintaining genome stability. Crit Rev Biochem Mol Biol 52:696-714 |
Dungrawala, Huzefa; Bhat, Kamakoti P; Le Meur, Rémy et al. (2017) RADX Promotes Genome Stability and Modulates Chemosensitivity by Regulating RAD51 at Replication Forks. Mol Cell 67:374-386.e5 |
Vujanovic, Marko; Krietsch, Jana; Raso, Maria Chiara et al. (2017) Replication Fork Slowing and Reversal upon DNA Damage Require PCNA Polyubiquitination and ZRANB3 DNA Translocase Activity. Mol Cell 67:882-890.e5 |
Reynolds, John J; Bicknell, Louise S; Carroll, Paula et al. (2017) Mutations in DONSON disrupt replication fork stability and cause microcephalic dwarfism. Nat Genet 49:537-549 |
Cortez, David (2017) Proteomic Analyses of the Eukaryotic Replication Machinery. Methods Enzymol 591:33-53 |
Bass, Thomas E; Luzwick, Jessica W; Kavanaugh, Gina et al. (2016) ETAA1 acts at stalled replication forks to maintain genome integrity. Nat Cell Biol 18:1185-1195 |
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