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Toxicology and Cancer Biology Faculty Publications

Series

2015

Humans

Articles 1 - 6 of 6

Full-Text Articles in Medicine and Health Sciences

The Dna Structure And Sequence Preferences Of Wrn Underlie Its Function In Telomeric Recombination Events, Deanna N. Edwards, Amrita Machwe, Li Chen, Vilhelm A. Bohr, David K. Orren Sep 2015

The Dna Structure And Sequence Preferences Of Wrn Underlie Its Function In Telomeric Recombination Events, Deanna N. Edwards, Amrita Machwe, Li Chen, Vilhelm A. Bohr, David K. Orren

Toxicology and Cancer Biology Faculty Publications

Telomeric abnormalities caused by loss of function of the RecQ helicase WRN are linked to the multiple premature ageing phenotypes that characterize Werner syndrome. Here we examine WRN's role in telomeric maintenance, by comparing its action on a variety of DNA structures without or with telomeric sequences. Our results show that WRN clearly prefers to act on strand invasion intermediates in a manner that favours strand invasion and exchange. Moreover, WRN unwinding of these recombination structures is further enhanced when the invading strand contains at least three G-rich single-stranded telomeric repeats. These selectivities are most pronounced at NaCl concentrations within …


The C-Terminal Domain (Ctd) Of Human Dna Glycosylaseneil1 Is Required For Forming Berosome Repair Complex With Dna Replication Proteins At The Replicating Genome: Dominant Negative Function Of The Ctd, Pavana M. Hegde, Arijit Dutta, Shiladitya Sengupta, Joy Mitra, Sanjay Adhikari, Alan E. Tomkinson, Guo-Min Li, Istvan Boldogh, Tapas K. Hazra, Sankar Mitra, Muralidhar L. Hegde Aug 2015

The C-Terminal Domain (Ctd) Of Human Dna Glycosylaseneil1 Is Required For Forming Berosome Repair Complex With Dna Replication Proteins At The Replicating Genome: Dominant Negative Function Of The Ctd, Pavana M. Hegde, Arijit Dutta, Shiladitya Sengupta, Joy Mitra, Sanjay Adhikari, Alan E. Tomkinson, Guo-Min Li, Istvan Boldogh, Tapas K. Hazra, Sankar Mitra, Muralidhar L. Hegde

Toxicology and Cancer Biology Faculty Publications

The human DNA glycosylase NEIL1 was recently demonstrated to initiate prereplicative base excision repair (BER) of oxidized bases in the replicating genome, thus preventing mutagenic replication. A significant fraction of NEIL1 in cells is present in large cellular complexes containing DNA replication and other repair proteins, as shown by gel filtration. However, how the interaction of NEIL1 affects its recruitment to the replication site for prereplicative repair was not investigated. Here, we show that NEIL1 binarily interacts with the proliferating cell nuclear antigen clamp loader replication factor C, DNA polymerase δ, and DNA ligase I in the absence of DNA …


Truncating Mutation In The Autophagy Gene Uvrag Confers Oncogenic Properties And Chemosensitivity In Colorectal Cancers, Shanshan He, Zhen Zhao, Yongfei Yang, Douglas O'Connell, Xiaowei Zhang, Soohwan Oh, Binyun Ma, Joo-Hyung Lee, Tian Zhang, Bino Varghese, Janae Yip, Sara Dolatshahi Pirooz, Ming Li, Yong Zhang, Guo-Min Li, Sue Ellen Martin, Keigo Machida, Chengyu Liang Aug 2015

Truncating Mutation In The Autophagy Gene Uvrag Confers Oncogenic Properties And Chemosensitivity In Colorectal Cancers, Shanshan He, Zhen Zhao, Yongfei Yang, Douglas O'Connell, Xiaowei Zhang, Soohwan Oh, Binyun Ma, Joo-Hyung Lee, Tian Zhang, Bino Varghese, Janae Yip, Sara Dolatshahi Pirooz, Ming Li, Yong Zhang, Guo-Min Li, Sue Ellen Martin, Keigo Machida, Chengyu Liang

Toxicology and Cancer Biology Faculty Publications

Autophagy-related factors are implicated in metabolic adaptation and cancer metastasis. However, the role of autophagy factors in cancer progression and their effect in treatment response remain largely elusive. Recent studies have shown that UVRAG, a key autophagic tumour suppressor, is mutated in common human cancers. Here we demonstrate that the cancer-related UVRAG frameshift (FS), which does not result in a null mutation, is expressed as a truncated UVRAGFS in colorectal cancer (CRC) with microsatellite instability (MSI), and promotes tumorigenesis. UVRAGFS abrogates the normal functions of UVRAG, including autophagy, in a dominant-negative manner. Furthermore, expression of UVRAGFS can …


Arsenic Inhibits Dna Mismatch Repair By Promoting Egfr Expression And Pcna Phosphorylation, Dan Tong, Janice Ortega, Christine Kim, Jian Huang, Liya Gu, Guo-Min Li Jun 2015

Arsenic Inhibits Dna Mismatch Repair By Promoting Egfr Expression And Pcna Phosphorylation, Dan Tong, Janice Ortega, Christine Kim, Jian Huang, Liya Gu, Guo-Min Li

Toxicology and Cancer Biology Faculty Publications

Both genotoxic and non-genotoxic chemicals can act as carcinogens. However, while genotoxic compounds lead directly to mutations that promote unregulated cell growth, the mechanism by which non-genotoxic carcinogens lead to cellular transformation is poorly understood. Using a model non-genotoxic carcinogen, arsenic, we show here that exposure to arsenic inhibits mismatch repair (MMR) in human cells, possibly through its ability to stimulate epidermal growth factor receptor (EGFR)-dependent tyrosine phosphorylation of proliferating cellular nuclear antigen (PCNA). HeLa cells exposed to exogenous arsenic demonstrate a dose- and time-dependent increase in the levels of EGFR and tyrosine 211-phosphorylated PCNA. Cell extracts derived from arsenic-treated …


Human Dna Exonuclease Trex1 Is Also An Exoribonuclease That Acts On Single-Stranded Rna, Fenghua Yuan, Tanmay Dutta, Ling Wang, Lei Song, Liya Gu, Liangyue Qian, Anaid Benitez, Shunbin Ning, Arun Malhotra, Murray P. Deutscher, Yanbin Zhang May 2015

Human Dna Exonuclease Trex1 Is Also An Exoribonuclease That Acts On Single-Stranded Rna, Fenghua Yuan, Tanmay Dutta, Ling Wang, Lei Song, Liya Gu, Liangyue Qian, Anaid Benitez, Shunbin Ning, Arun Malhotra, Murray P. Deutscher, Yanbin Zhang

Toxicology and Cancer Biology Faculty Publications

3' repair exonuclease 1 (TREX1) is a known DNA exonuclease involved in autoimmune disorders and the antiviral response. In this work, we show that TREX1 is also a RNA exonuclease. Purified TREX1 displays robust exoribonuclease activity that degrades single-stranded, but not double-stranded, RNA. TREX1-D200N, an Aicardi-Goutieres syndrome disease-causing mutant, is defective in degrading RNA. TREX1 activity is strongly inhibited by a stretch of pyrimidine residues as is a bacterial homolog, RNase T. Kinetic measurements indicate that the apparent Km of TREX1 for RNA is higher than that for DNA. Like RNase T, human TREX1 is active in degrading native …


Chemoselective Detection And Discrimination Of Carbonyl-Containing Compounds In Metabolite Mixtures By 1H-Detected 15N Nuclear Magnetic Resonance, Andrew N. Lane, Sengodagounder Arumugam, Pawel Lorkiewicz, Richard M. Higashi, Sébastien Laulhé, Michael H. Nantz, Hunter N. B. Moseley, Teresa W-M Fan May 2015

Chemoselective Detection And Discrimination Of Carbonyl-Containing Compounds In Metabolite Mixtures By 1H-Detected 15N Nuclear Magnetic Resonance, Andrew N. Lane, Sengodagounder Arumugam, Pawel Lorkiewicz, Richard M. Higashi, Sébastien Laulhé, Michael H. Nantz, Hunter N. B. Moseley, Teresa W-M Fan

Toxicology and Cancer Biology Faculty Publications

NMR spectra of mixtures of metabolites extracted from cells or tissues are extremely complex, reflecting the large number of compounds that are present over a wide range of concentrations. Although multidimensional NMR can greatly improve resolution as well as improve reliability of compound assignments, lower abundance metabolites often remain hidden. We have developed a carbonyl-selective aminooxy probe that specifically reacts with free keto and aldehyde functions, but not carboxylates. By incorporating 15N in the aminooxy functional group, 15N-edited NMR was used to select exclusively those metabolites that contain a free carbonyl function while all other metabolites are rejected. …