DNA damage accumulates during life and is thought to contribute to aging and genomic instability. Therefore, defining those proteins and pathways that maintain genomic instability is critical in preventing aging and age-related degeneration. This project aims to understand what roles the five human RecQ helicases play in DNA repair and genomic stability. One major goal of our lab is to delineate the unique and complementary roles of the human RecQ helicases, with the expectation that we might fully explain each proteins function. Each RecQ possesses helicase and strand annealing activity as well as domains that confer unique functionality. We've demonstrated that all the RecQ helicases can be recruited to laser-induced double strand breaks (DSB), however the details of how each RecQ participates in DSB is less clear and therefore efforts are ongoing to dissect more precisely the role of each RecQ in DSB repair. Recently, we showed that RECQL4 interacts with Ku and further that loss of RECQL4 alters in vivo DSB repair efficiency. This expands the list of RecQs that interact with Ku to three: WRN, RECQL1 and RECQL4. The definitive role that RECQL4 plays in NHEJ and/or Alt-NHEJ is being explored. Another common interacting partner for the human RecQ proteins is PARP1. PARP1 is recruited early to DSB sites and orchestrates the recruitment and retention of many components of the DNA repair and DNA damage response network. We are investigating the mechanisms of interaction between RecQs and PARP1, mapping their domains of interaction and determining how significant the interactions are using survival assays. PARP1 inhibitors are used as anti-cancer therapies and since PARP1 is such a central play in the DNA damage response network, PARP inhibitors may alter RecQ protein functions. We are exploring these and other interaction partners to define the roles that RecQs play in DNA repair. In addition, our lab, in collaboration with others, continues to identify and characterize potential RecQ inhibitors. Thus far, inhibitors for both WRN and BLM have been identified, however both are suboptimal, thus we are continuing to screen for more optimized inhibitors.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIAAG000726-23
Application #
9147329
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
23
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Aging
Department
Type
DUNS #
City
State
Country
Zip Code
Lu, Huiming; Shamanna, Raghavendra A; de Freitas, Jessica K et al. (2017) Cell cycle-dependent phosphorylation regulates RECQL4 pathway choice and ubiquitination in DNA double-strand break repair. Nat Commun 8:2039
Lu, Huiming; Shamanna, Raghavendra A; Keijzers, Guido et al. (2016) RECQL4 Promotes DNA End Resection in Repair of DNA Double-Strand Breaks. Cell Rep 16:161-173
Arora, Arvind; Abdel-Fatah, Tarek M A; Agarwal, Devika et al. (2016) Clinicopathological and prognostic significance of RECQL5 helicase expression in breast cancers. Carcinogenesis 37:63-71
Arora, Arvind; Agarwal, Devika; Abdel-Fatah, Tarek Ma et al. (2016) RECQL4 helicase has oncogenic potential in sporadic breast cancers. J Pathol 238:495-501
Shamanna, Raghavendra A; Lu, Huiming; de Freitas, Jessica K et al. (2016) WRN regulates pathway choice between classical and alternative non-homologous end joining. Nat Commun 7:13785
Shamanna, Raghavendra A; Lu, Huiming; Croteau, Deborah L et al. (2016) Camptothecin targets WRN protein: mechanism and relevance in clinical breast cancer. Oncotarget 7:13269-84
Khadka, Prabhat; Croteau, Deborah L; Bohr, Vilhelm A (2016) RECQL5 has unique strand annealing properties relative to the other human RecQ helicase proteins. DNA Repair (Amst) 37:53-66
Sarkar, Jaya; Wan, Bingbing; Yin, Jinhu et al. (2015) SLX4 contributes to telomere preservation and regulated processing of telomeric joint molecule intermediates. Nucleic Acids Res 43:5912-23
Edwards, Deanna N; Machwe, Amrita; Chen, Li et al. (2015) The DNA structure and sequence preferences of WRN underlie its function in telomeric recombination events. Nat Commun 6:8331
Bürkle, Alexander; Grune, Tilman; Gonos, Efstathios S et al. (2015) Editorial. Mech Ageing Dev 151:1

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