DNA replication is a fundamental process on which all organisms depend for faithful passage of genetic material from one generation to the next. The DNA replication process is often """"""""stressed"""""""" either by mutations or by exogenous reagents that can cause DNA damage or impediments to the replication machinery. Replication stress can give rise to genomic instability and may ultimately lead to diseases including cancer. My main research interest is how defective replication cause genomic instability. The general hypothesis governing this proposal is that single-stranded DNA (ssDNA) production upon replication fork stalling and destablization in replication checkpoint-deficient mutants is a potentially lethal event that prevents complete synthesis of the genome, causes chromosomal breakage, and ultimately genomic instability.
The specific aims of this project are: 1. Investigate the link between extensive ssDNA formation during replication stress and chromosome breakage using the genome-wide ssDNA and chromosome breakage mapping techniques developed by the applicant in combination with other genetic approaches. 2. Elucidate the mechanism/cause of replication fork instability in checkpoint mutants in HU by examining the structural/compositional changes that occur in the replication complex upon replication stress by a minichromosome purification system coupled with mass spectrometry. 3. Identify origins of replication and chromosome fragile sites in humans using a combination of ssDNA and chromosome breakage mapping that have been adapted for the mammalian systems.
The proposed project will have a direct impact on our understanding of two important features of the human genome, origins of replication and chromosome fragile sites, and how defects in the replication process induce genomic instability and human diseases such as cancer.
|Peng, Jie; Feng, Wenyi (2016) Incision of damaged DNA in the presence of an impaired Smc5/6 complex imperils genome stability. Nucleic Acids Res 44:10216-10229|
|Hang, Lisa E; Peng, Jie; Tan, Wei et al. (2015) Rtt107 Is a Multi-functional Scaffold Supporting Replication Progression with Partner SUMO and Ubiquitin Ligases. Mol Cell 60:268-79|
|Hoffman, Elizabeth A; McCulley, Andrew; Haarer, Brian et al. (2015) Break-seq reveals hydroxyurea-induced chromosome fragility as a result of unscheduled conflict between DNA replication and transcription. Genome Res 25:402-12|
|McCulley, Andrew; Haarer, Brian; Viggiano, Susan et al. (2014) Chemical suppression of defects in mitotic spindle assembly, redox control, and sterol biosynthesis by hydroxyurea. G3 (Bethesda) 4:39-48|
|Peng, Jie; Raghuraman, M K; Feng, Wenyi (2014) Analysis of replication timing using synchronized budding yeast cultures. Methods Mol Biol 1170:477-99|
|Peng, Jie; Raghuraman, M K; Feng, Wenyi (2014) Analysis of ssDNA gaps and DSBs in genetically unstable yeast cultures. Methods Mol Biol 1170:501-15|