Learn More
The phenotypically similar hamster mutants irs1 and irs1SF exhibit high spontaneous chromosome instability and broad-spectrum mutagen sensitivity, including extreme sensitivity to DNA cross-linking agents. The human XRCC2 and XRCC3 genes, which functionally complement irs1 and irs1SF, respectively, were previously mapped in somatic cell hybrids.(More)
The b1012 operon of Escherichia coli K-12, which is composed of seven unidentified ORFs, is one of the most highly expressed operons under control of nitrogen regulatory protein C. Examination of strains with lesions in this operon on Biolog Phenotype MicroArray (PM3) plates and subsequent growth tests indicated that they failed to use uridine or uracil as(More)
The human XRCC1 gene has been shown to be involved in DNA strand-break repair using the Chinese hamster ovary cell mutant EM9. The purpose of this study was to characterize the expression of Xrcc-1 to determine if there is tissue-specific expression and to provide a baseline of information for future studies that may involve altering Xrcc-1 expression in(More)
ERCC4 is an essential human gene in the nucleotide excision repair (NER) pathway, which is responsible for removing UV-C photoproducts and bulky adducts from DNA. Among the NER genes, ERCC4 and ERCC1 are also uniquely involved in removing DNA interstrand cross-linking damage. The ERCC1-ERCC4 heterodimer, like the homologous Rad10-Rad1 complex, was recently(More)
O(6)-methylguanine (O(6)mG) is a potent mutagenic and procarcinogenic DNA lesion. Organisms have evolved with a DNA repair mechanism that largely ameliorates the deleterious effects of O(6)mG through a direct reversal mechanism by a protein termed O(6)-methylguanine-DNA methyltransferase (MGMT). However, the contribution of O(6)mG to carcinogenesis, in the(More)
The Chinese hamster ovary (CHO) mutant UV40 cell line is hypersensitive to UV and ionizing radiation, simple alkylating agents, and DNA cross-linking agents. The mutant cells also have a high level of spontaneous chromosomal aberrations and 3-fold elevated sister chromatid exchange. We cloned and sequenced a human cDNA, designated XRCC9, that partially(More)
Members of the Myc family of transcription factors are key regulators of cell proliferation, and excessive levels of Myc lead to tumor formation. Mad family proteins are related to Myc, but they antagonize the oncogenic activity of Myc in cell-culture assays. Here, we examine current models of Mad function and the relationship between Mad and Myc in cell(More)
Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; little is known about other ferric citrate-binding proteins. Here we report a unique siderophore-binding(More)
XRCC1 is a DNA repair gene involved in rejoining DNA strand-breaks. We used baboon as an animal model to determine the levels of XRCC1 gene expression in different tissues. Baboons were selected because they are evolutionarily closely related to humans. A single 2.2 kb transcript was detected in all tissues tested by northern blot analysis, with variations(More)
One way to better understand the contribution of DNA repair, DNA damage, and mutagenesis in aging would be to enhance DNA repair activity, lower DNA damage, and lower mutagenesis. Because the repair protein O6-methylguanine-DNA methyltransferase (MGMT) acts alone and stoichiometrically, the human MGMT (hMGMT) cDNA was selected to test the feasibility of(More)