The causality of human environmental exposures and disease development is irrefutable. Human cells deploy highly coordinated and structured mechanisms in response to ubiquitous environmentally related genotoxic damage. Amongst these, versatile nucleotide excision repair (NER) efficiently mends helix-distorting lesions by global genomic repair (GGR) and transcription-coupled repair (TCR) sub-pathways. Ongoing work of past project years has provided in-depth mechanistic insights about the individual steps of GGR and TCR as well as the crucial elements of their regulation. This continuation grant application will extend the scope of these studies along a similar overall theme to demonstrate the role of ubiquitination/deubiquitination during the initial damage recognition phase and following the successful completion of repair during the restoration of intact chromatin. Overall work is based on the premise that specific ubiquitinating/ deubiquitinating activities orchestrate the coordinated targeting of core repair and regulatory factors to damage sites. As the final aftermath of damage response, the deubiquitination events herald the cell cycle progression and transcription recovery. Thus, the proposed studies plan to dissect the dynamics of DNA damage recognition and its elaborate processing against the regulatory backdrop of specific ubiquitination/ deubiquitination of key DNA repair proteins. Four inter-related specific aims are proposed to, (1) reveal the cellular components operating in deubiquitination of crucial NER recognition factor XPC during GGR; (2) establish the underlying mechanism by which Cul4A-DDB1-CSA E3 ubiquitin ligase complex mediates the regulation of TCR; (3) delineate the molecular machinery operational in incorporating the mono- ubiquitinated histone 2A (uH2A) within repaired genomic sites; and (4) distinguish the role of putative deubiquitinase and functional relevance of uH2A deubiquitination in restoring chromatin. Powerful in situ technology and related resources established in the previous project years will be applied to experimentally dissect the molecular/cellular components of ubiquitination/deubiquitination via spatiotemporal in vivo assembly/disassembly of repair and regulatory factors, in vivo and in vitro DNA-protein/protein-protein interactions and kinetics of lesion removal in conjunction with the ultimate fate of ubiquitinated factors. Identification, function and regulation of these critical interacting factors and repair pathway events influencing the overall genomic stability, so fundamental to normal cellular existence, has obvious significance in understanding the cause and treating human environment based diseases.

Public Health Relevance

The causality of human environmental exposures and disease development is irrefutable. Human cells deploy highly coordinated and structured mechanisms in response to ubiquitous environmentally related genotoxic damage. Amongst these, versatile nucleotide excision repair efficiently mends helix-distorting genomic lesions that impair normal cell function. Main goal of this continuation grant is to demonstrate the role of ubiquitination/deubiquitination during the initial damage recognition phase and following the successful completion of repair during the restoration of intact chromatin. Identification, function and regulation of critical interacting factors and repair pathway events influencing the overall genomic stability, so fundamental to normal cellular existence, has obvious significance in understanding the cause and treating human environment based diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
4R01ES002388-29
Application #
8969677
Study Section
Xenobiotic and Nutrient Disposition and Action Study Section (XNDA)
Program Officer
Reinlib, Leslie J
Project Start
1981-09-01
Project End
2017-11-30
Budget Start
2015-12-01
Budget End
2017-11-30
Support Year
29
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Ohio State University
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
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Zhu, Qianzheng; Wani, Altaf A (2017) Nucleotide Excision Repair: Finely Tuned Molecular Orchestra of Early Pre-incision Events. Photochem Photobiol 93:166-177
Zhu, Qianzheng; Wei, Shengcai; Sharma, Nidhi et al. (2017) Human CRL4DDB2 ubiquitin ligase preferentially regulates post-repair chromatin restoration of H3K56Ac through recruitment of histone chaperon CAF-1. Oncotarget 8:104525-104542
Rehmani, Nida; Zafar, Atif; Arif, Hussain et al. (2017) Copper-mediated DNA damage by the neurotransmitter dopamine and L-DOPA: A pro-oxidant mechanism. Toxicol In Vitro 40:336-346
He, Jinshan; Zhu, Qianzheng; Wani, Gulzar et al. (2016) Valosin-containing Protein (VCP)/p97 Segregase Mediates Proteolytic Processing of Cockayne Syndrome Group B (CSB) in Damaged Chromatin. J Biol Chem 291:7396-408
Han, Chunhua; Srivastava, Amit Kumar; Cui, Tiantian et al. (2016) Differential DNA lesion formation and repair in heterochromatin and euchromatin. Carcinogenesis 37:129-38
Ray, Alo; Blevins, Chessica; Wani, Gulzar et al. (2016) ATR- and ATM-Mediated DNA Damage Response Is Dependent on Excision Repair Assembly during G1 but Not in S Phase of Cell Cycle. PLoS One 11:e0159344
Han, Chunhua; Wani, Gulzar; Zhao, Ran et al. (2015) Cdt2-mediated XPG degradation promotes gap-filling DNA synthesis in nucleotide excision repair. Cell Cycle 14:1103-15
Zhao, Ran; Cui, Tiantian; Han, Chunhua et al. (2015) DDB2 modulates TGF-? signal transduction in human ovarian cancer cells by downregulating NEDD4L. Nucleic Acids Res 43:7838-49
Qian, J; Pentz, K; Zhu, Q et al. (2015) USP7 modulates UV-induced PCNA monoubiquitination by regulating DNA polymerase eta stability. Oncogene 34:4791-6

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