Interstrand crosslinks (ICLs) are deleterious DNA damages in which both strands are covalently bound together, generating a stalled replication state cytotoxic to cells. Defective repair of ICLs is associated with Fanconi Anemia syndrome (FA) and predisposition to cancer. At least seventeen FA genes have been identified up to date. This proposal focuses on a specific FA protein, FANCA, a member of the FA core complex that is mutated in 64% of the entire FA patient population and does not have a clear function. Our preliminary study shows that FANCA destabilizes (unwinds) DNA helix and recognizes DNA interstrand crosslink damage (ICL) in a replication fork. Intriguingly, FANCA anneals single-strand DNA and catalyzes strand exchange as well. Furthermore, FANCA synergistically interacts with Rad51, the major recombinase in double strand break (DSB) repair. Based on these data, we hypothesize that FANCA directly participates in repair of interstrand crosslinks through its DNA-destabilizing (`unwinding') activity and facilitates subsequent repair of double strand DNA breaks by catalyzing strand annealing and exchange. In order to delineate the role of FANCA in DNA repair, we will use a biochemically defined in vitro system, a cell-based DSB repair study system, and a living cell imaging system to accomplish four aims: 1) Delineate the molecular mechanism of how FANCA catalyzes DNA `unwinding', single-strand annealing, and strand exchange. 2) Determine the role of FANCA in recognition and incision of DNA interstrand crosslinks. 3) Study the biological role of FANCA in double strand break repair. 4) Examine the physiological role of the DNA `unwinding', single- strand annealing, and strand exchange activities of FANCA in the etiology of Fanconi anemia. Understanding the role of FANCA in DNA repair will not only contribute to the overall clarification of the ICL repair process, but also provide novel insights into the etiology of Fanconi anemia and its associated cancer.

Public Health Relevance

Fanconi anemia affects children by causing bone marrow failure and predisposition to cancers. Mutations in FANCA gene cause 64% of the entire Fanconi anemia patient population. Exploring the role of FANCA in DNA repair is therefore directly related to human health. Our proposal will provide novel mechanistic insights into the etiology of Fanconi anemia and an important damage repair pathway that has not been well understood.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL131013-01A1
Application #
9173233
Study Section
Radiation Therapeutics and Biology Study Section (RTB)
Program Officer
Qasba, Pankaj
Project Start
2016-07-01
Project End
2020-02-29
Budget Start
2016-07-01
Budget End
2017-02-28
Support Year
1
Fiscal Year
2016
Total Cost
$389,879
Indirect Cost
$119,013
Name
University of Miami School of Medicine
Department
Biochemistry
Type
Schools of Medicine
DUNS #
052780918
City
Coral Gables
State
FL
Country
United States
Zip Code
33146
Benitez, Anaid; Liu, Wenjun; Palovcak, Anna et al. (2018) FANCA Promotes DNA Double-Strand Break Repair by Catalyzing Single-Strand Annealing and Strand Exchange. Mol Cell 71:621-628.e4
Zhou, Jeff Xiwu; Yang, Xiaoyan; Ning, Shunbin et al. (2017) Identification of KANSARL as the first cancer predisposition fusion gene specific to the population of European ancestry origin. Oncotarget 8:50594-50607
Palovcak, Anna; Liu, Wenjun; Yuan, Fenghua et al. (2017) Maintenance of genome stability by Fanconi anemia proteins. Cell Biosci 7:8
Mittal, Rahul; Grati, M'hamed; Sedlacek, Miloslav et al. (2016) Characterization of ATPase Activity of P2RX2 Cation Channel. Front Physiol 7:186