Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00492 (hypoxanthine-guanine phosphoribosyltransferase)
 2,385 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Conditions were characterized for maximizing the uptake of exogenous mammalian cell DNA by hypoxanthine-guanine phosphoribosyltransferase-deficient Chinese hamster lung cells. Recipient cell cultures in an exponential growth phase were found to be more competent in taking up DNA than stationary cultures. Polyornithine enhanced the uptake of exogenous DNA more reproducibly and to a greater extent than did any of the other facilitators tested (DEAE-dextran, CaCl2, latex spheres, spermine, polylysine and polyarginine). Maximal DNA incorporation occurred when polyornithine and DNA were mixed together prior to inoculation. About 25-30% of the DNA inoculum became deoxyribonuclease-resistant in a typical experiment utilizing polyornithine as the facilitator. Both homologous and heterologous exogenous DNAs rapidly became associated with recipient cell nuclei: approximately 95% of the deoxyribonuclease-resistant donor DNA was nuclear-associated 15 min after inoculation.
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PMID:Optimal conditions for uptake of exogenous DNA by Chinese hamster lung cells deficient in hypoxanthine-guanine phosphoribosyltransferase. 116 8

The relationship between DNA-adduct formation and mutagenicity of two heterocyclic aromatic amines associated with cooked foods was determined in a CHO cell strain lacking nucleotide excision repair. Cells were exposed to tritiated IQ (2-amino-3-methylimidazo[4,5-f]quinoline) or Trp-P-2 (3-amino-1-methyl-5H-pyrido[4,3-b]indole) supplemented with hamster S9 microsomal fraction for metabolic activation. DNA from nuclei was isolated by DNAase-mediated elution from polycarbonate filters after RNAase and proteinase treatment. The presumed metabolites of both compounds bound to DNA in a dose-dependent fashion. Although the dose required to produce 50% cell killing was 15 times higher for IQ than Trp-P-2, the amount of radioactive material bound to DNA at that dose was about 10-fold lower with IQ. When mutations at the hprt and aprt loci were compared with the estimated levels of adducts, the calculated mutagenic efficiency of the adducts was about 4 mutations per 1000 adducts for both compounds, assuming a target sequence of 1000 base pairs for either locus. We conclude that IQ is acting as a weak mutagen in this system because its extracellular metabolites either do not reach or do not react efficiently with the DNA of the CHO cells.
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PMID:Comparative mutagenic efficiencies of the DNA adducts from the cooked-food-related mutagens Trp-P-2 and IQ in CHO cells. 398 43