Nucleotide Excision Repair (NER) is a versatile DNA repair pathway involved in the removal of diverse lesions, including those formed by UV light, from DNA. The importance of NER is underscored by the fact that the cancer-prone inherited disorder xeroderma pigmentosum is caused by defects in various NER genes. NER acts by the concerted action of over 30 proteins that sequentially assemble at sites of UV damage. Although the basic biochemical transactions involved in NER have been discerned, it is less well understood how the individual steps are coordinated to ensure smooth progression through the pathway. The research outlined here combines biochemical, cell biological, chemical and structural approaches to study the regulation and coordination of the dual incision and repair synthesis steps in NER. The proposal is guided by the hypothesis that the incisions, 5'to the lesion by ERCC1-XPF and 3'to the lesion by XPG, are temporarily and spatially regulated to avoid the formation of deleterious breaks and gaps in the process. We will test the specific hypothesis that this coordination is achieved by protein-protein interactions, DNA binding and catalytic activities as follows: 1) New structural information will be used to reassign and characterize the XPA-ERCC1 interaction domains and we will study how XPA recruits ERCC1-XPF to sites of NER. 2) We will study how individual DNA binding domains of ERCC1-XPF contribute to its catalytic activity and progression through the NER pathway. 3) We will investigate how the order of incisions by ERCC1-XPF and XPG and the coordination of incision and repair synthesis activities avoids the formation of single-stranded DNA gaps following excision of a 30 nucleotide long oligonuelcotide containing the damage. Our studies will provide new insight into the molecular basis of the regulation of a complex biochemical pathway in human cells as well as the molecular basis of inherited disease and the etiology of cancer. Since NER proteins also counteract the action of many clinically important antitumor agents, our studies will also contribute new targets for therapeutic intervention. Project Narrative: Nucleotide excision repair (NER) is a complex DNA repair pathway that counteracts damage to DNA caused by UV light, environmental agents and cancer chemotherapeutic drugs. Defects in NER genes result in the cancer-prone inherited disorder xeroderma pigmentosum and our interdisciplinary studies of this pathway contribute to our understanding of the molecular basis of human disease. Since NER proteins also contribute to the resistance of tumor cells to anti-cancer agents our investigations may also provide new targets for anti- tumor therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM080454-02S1
Application #
7899485
Study Section
Cancer Etiology Study Section (CE)
Program Officer
Portnoy, Matthew
Project Start
2009-08-14
Project End
2011-07-31
Budget Start
2009-08-14
Budget End
2011-07-31
Support Year
2
Fiscal Year
2009
Total Cost
$262,759
Indirect Cost
Name
State University New York Stony Brook
Department
Pharmacology
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
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Slean, Meghan M; Reddy, Kaalak; Wu, Bin et al. (2013) Interconverting conformations of slipped-DNA junctions formed by trinucleotide repeats affect repair outcome. Biochemistry 52:773-85
Sidorenko, Victoria S; Yeo, Jung-Eun; Bonala, Radha R et al. (2012) Lack of recognition by global-genome nucleotide excision repair accounts for the high mutagenicity and persistence of aristolactam-DNA adducts. Nucleic Acids Res 40:2494-505
Enoiu, Milica; Ho, The Vinh; Long, David T et al. (2012) Construction of plasmids containing site-specific DNA interstrand cross-links for biochemical and cell biological studies. Methods Mol Biol 920:203-19
Yeo, Jung-Eun; Khoo, Andy; Fagbemi, Adebanke F et al. (2012) The efficiencies of damage recognition and excision correlate with duplex destabilization induced by acetylaminofluorene adducts in human nucleotide excision repair. Chem Res Toxicol 25:2462-8
Su, Yan; Orelli, Barbara; Madireddy, Advaitha et al. (2012) Multiple DNA binding domains mediate the function of the ERCC1-XPF protein in nucleotide excision repair. J Biol Chem 287:21846-55
Fagbemi, Adebanke F; Orelli, Barbara; Scharer, Orlando D (2011) Regulation of endonuclease activity in human nucleotide excision repair. DNA Repair (Amst) 10:722-9
Gregg, Siobhan Q; Robinson, Andria Rasile; Niedernhofer, Laura J (2011) Physiological consequences of defects in ERCC1-XPF DNA repair endonuclease. DNA Repair (Amst) 10:781-91
Orelli, Barbara; McClendon, T Brooke; Tsodikov, Oleg V et al. (2010) The XPA-binding domain of ERCC1 is required for nucleotide excision repair but not other DNA repair pathways. J Biol Chem 285:3705-12
Guainazzi, Angelo; Schärer, Orlando D (2010) Using synthetic DNA interstrand crosslinks to elucidate repair pathways and identify new therapeutic targets for cancer chemotherapy. Cell Mol Life Sci 67:3683-97

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