Defects in DNA repair can lead to genome instability, a hallmark of cancer. Oxidative DNA damage is a major source of mutation load in living organisms and plays a role in carcinogenesis and aging. The 8-oxo-7,8-dihydrodeoxyguanine (8-oxoG) lesion is a major stable product of oxidative damage and has the most deleterious effects because it can mispair with adenine during DNA replication. Thus, repair ol A/8-oxoG and C/8-oxoG by hMYH (MutY adenine glycosylase homolog), hOGG1 (an 8-oxoG glycosylase), and hMSH2/hMSH6 dependent mismatch repair pathways provide levels of defense against oxidative stress The overall goals of this project is to understand the role of hMYH pathway in controlling carcinogenesis and its interplay with other repair pathways in response to oxidative stress such as treatments by hydrogen peroxide and ionizing radiation. The interactions of hMYH with replication proteins hPCNA and hRPA, with repai] enzymes hAPE1 and hMSH6, as well as cell cycle checkpoint proteins hHusl/hRadl/hRad9 will be investigated. (I) Alterations in the interactions of hMYH with hPCNA and hHusl under oxidative stress will be investigated. The interacting domains on hMYH and hHusl will be mapped and the significance of their functional interaction will be tested in vivo. Working models that a molecular switch of hMYH-hPCNA tc hMYH-hRad9/hRadl/hHusl occurs to induce DNA damage response and that hMYH may recruit_ hRad9/hRadl/hHusl to the lesion sites will be tested. (II) Interaction between hMYH and hMSH6 will be elucidated both in vitro and in vivo. Fission yeast S. pombe will be used as a model system to test the in viw function of hMYH mutants. (III) Co-localization of hMYH with hAPE 1, hPCNA, hHus 1, hRPA, and hMSH6 ir repair and replication loci will be examined. (IV) The phosphorylation state of hMYH after DNA damage, the kinase responsible for the hMYH phosphorylation, and the phosphorylation site(s) of hMYH will be determined. The correlation of hMYH activities with protein phosphorylation or certain protein-protein interaction(s) after DNA damage will be examined. This study will advance our understanding of the role of DNA repair in tumor susceptibility.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA078391-08
Application #
6929941
Study Section
Radiation Study Section (RAD)
Program Officer
Okano, Paul
Project Start
1998-08-14
Project End
2008-04-30
Budget Start
2005-07-01
Budget End
2006-04-30
Support Year
8
Fiscal Year
2005
Total Cost
$279,180
Indirect Cost
Name
University of Maryland Baltimore
Department
Biochemistry
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Hwang, Bor-Jang; Jin, Jin; Gunther, Randall et al. (2015) Association of the Rad9-Rad1-Hus1 checkpoint clamp with MYH DNA glycosylase and DNA. DNA Repair (Amst) 31:80-90
Lim, Pei Xin; Patel, Darshil R; Poisson, Kelsey E et al. (2015) Genome Protection by the 9-1-1 Complex Subunit HUS1 Requires Clamp Formation, DNA Contacts, and ATR Signaling-independent Effector Functions. J Biol Chem 290:14826-40
Hwang, Bor-Jang; Jin, Jin; Gao, Ying et al. (2015) SIRT6 protein deacetylase interacts with MYH DNA glycosylase, APE1 endonuclease, and Rad9-Rad1-Hus1 checkpoint clamp. BMC Mol Biol 16:12
Jin, Jin; Hwang, Bor-Jang; Chang, Po-Wen et al. (2014) Interaction of apurinic/apyrimidinic endonuclease 2 (Apn2) with Myh1 DNA glycosylase in fission yeast. DNA Repair (Amst) 15:1-10
Hwang, Bor-Jang; Shi, Gouli; Lu, A-Lien (2014) Mammalian MutY homolog (MYH or MUTYH) protects cells from oxidative DNA damage. DNA Repair (Amst) 13:10-21
Hwang, Bor-Jang; Madabushi, Amrita; Jin, Jin et al. (2014) Histone/protein deacetylase SIRT1 is an anticancer therapeutic target. Am J Cancer Res 4:211-21
Luncsford, Paz J; Manvilla, Brittney A; Patterson, Dimeka N et al. (2013) Coordination of MYH DNA glycosylase and APE1 endonuclease activities via physical interactions. DNA Repair (Amst) 12:1043-52
Madabushi, Amrita; Hwang, Bor-Jang; Jin, Jin et al. (2013) Histone deacetylase SIRT1 modulates and deacetylates DNA base excision repair enzyme thymine DNA glycosylase. Biochem J 456:89-98
Chang, Dau-Yin; Shi, Guoli; Durand-Dubief, Mickael et al. (2011) The role of MutY homolog (Myh1) in controlling the histone deacetylase Hst4 in the fission yeast Schizosaccharomyces pombe. J Mol Biol 405:653-65
Luncsford, Paz J; Chang, Dau-Yin; Shi, Guoli et al. (2010) A structural hinge in eukaryotic MutY homologues mediates catalytic activity and Rad9-Rad1-Hus1 checkpoint complex interactions. J Mol Biol 403:351-70

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