Dna Mismatch Repair System
Mostrando 1-12 de 140 artigos, teses e dissertações.
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1. Prevalência de Pseudomonas aeruginosa hipermutante em pacientes com fibrose cística e associação com resistência antimicrobiana em condições plantônicas e em biofilme
Foram avaliados 528 isolados clínicos de Pseudomonas aeruginosa de 131 pacientes fibrocísticos atendidos em um centro de referência em fibrose cística (FC) durante o período de 2005 a 2008. 135 isolados clínicos (25,6%) apresentaram subpopulação hipermutante (isolados com altas taxas de mutações) utilizando teste modificado de suscetibilidade aos a
Publicado em: 2011
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2. Leucoplasias bucais: estudo comparativo entre o grau histológico de displasia, imunoexpressão de hMLH1 e p53 e análise quantitativa de AgNOR
hMLH1 is a protein of the mammalian mismatch repair system (MMR), which maintains genomic stability during repeated duplication. Investigations point to a role of hMLH1 in oral carcinogenesis, and its expression pattern may be related to epigenetic events and microsatellite instability in oral leukoplakias and squamous cell carcinomas. It seems that those al
Publicado em: 2010
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3. The presence of proteins hMLH1 and hMSH6 of DNA mismatch repair system in actinic cheilitis and squamous cell carcinoma of the lip / "A presença das proteínas hMLH1 e hMSH6 do sistema de reparo do mau pareamento do DNA em queilites actínicas e carcinomas epidermóides de lábio"
Actinic cheilitis (AC) results from chronic and excessive exposure of the lips to the ultraviolet radiation in sunlight. AC is recognized as a potentially malignant condition and it is estimated that 10% to 20% will become lip squamous cell carcinoma (LSCC). It has been suggested that virtually every LSCC was initially AC. It is well known that solar radiati
Publicado em: 2006
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4. Uracil-DNA glycosylase affects mismatch repair efficiency in transformation and bisulfite-induced mutagenesis in Streptococcus pneumoniae.
The generalized mismatch repair system of Streptococcus pneumoniae (the Hex system) can eliminate base pair mismatches arising in heteroduplex DNA during transformation or by DNA polymerase errors during replication. Mismatch repair is most likely initiated at nicks or gaps. The present work was started to examine the hypothesis that strand discontinuities a
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5. The cellular mismatch repair system is able to repair mismatches within MLV retroviral double-stranded DNA at a low frequency
Eukaryotic cells possess several distinct mismatch repair pathways. A mismatch can be introduced in retroviral double-stranded DNA by a pre-existing mutation within the primer binding site (PBS) of the viral RNA genome. In order to evaluate mismatch repair of retroviral double-stranded DNA, Moloney leukemia virus (MLV)-based vectors with a mutation in their
Oxford University Press.
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6. Mismatch-stimulated killing.
DNA duplexes with or without mismatches and with or without adenine-methylated GATC sequences were prepared from separated strands of bacteriophage lambda DNA and used to transfect Escherichia coli. Unmethylated heteroduplexes containing one or more repairable mismatches transfect cells with a functioning mismatch repair system less efficiently than they tra
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7. Mismatch repair in Xenopus egg extracts: DNA strand breaks act as signals rather than excision points.
In Xenopus egg extracts, DNA strand breaks (nicks) located 3' or 5' to a mismatch cause an overall 3-fold stimulation of the repair of the mismatch in circular heteroduplex DNA molecules. The increase in mismatch repair is almost entirely due to an increase in repair of the nicked strand, which is stimulated 5-fold. Repair synthesis is centered to the mismat
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8. Dual roles for DNA sequence identity and the mismatch repair system in the regulation of mitotic crossing-over in yeast
Sequence divergence acts as a potent barrier to homologous recombination; much of this barrier derives from an antirecombination activity exerted by mismatch repair proteins. An inverted repeat assay system with recombination substrates ranging in identity from 74% to 100% has been used to define the relationship between sequence divergence and the rate of m
The National Academy of Sciences of the USA.
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9. Mismatch Repair Processing of Carcinogen-DNA Adducts Triggers Apoptosis
The DNA mismatch repair pathway is well known for its role in correcting biosynthetic errors of DNA replication. We report here a novel role for mismatch repair in signaling programmed cell death in response to DNA damage induced by chemical carcinogens. Cells proficient in mismatch repair were highly sensitive to the cytotoxic effects of chemical carcinogen
American Society for Microbiology.
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10. Mutation, recombination, and incipient speciation of bacteria in the laboratory
Mutations in the DNA mismatch repair system increase mutation and recombination. They may thereby promote the genetic divergence that underlies speciation, after which the reacquisition of a functional repair system may sustain that divergence by creating a barrier to recombination. We tested several lines of Escherichia coli, derived from a common ancestor
The National Academy of Sciences.
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11. The extreme mutator effect of Escherichia coli mutD5 results from saturation of mismatch repair by excessive DNA replication errors.
Escherichia coli mutator mutD5 is the most potent mutator known. The mutD5 mutation resides in the dnaQ gene encoding the proofreading exonuclease of DNA polymerase III holoenzyme. It has recently been shown that the extreme mutability of this strain results, in addition to a proofreading defect, from a defect in mutH, L, S-encoded postreplicational DNA mism
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12. Mutation spectrum in Escherichia coli DNA mismatch repair deficient (mutH) strain.
The Dam-directed post-replicative mismatch repair system of Escherichia coli removes base pair mismatches from DNA. The products of the mutH, mutL and mutS genes, among others, are required for efficient mismatch repair. Absence of any of these gene products leads to persistence of mismatches in DNA with a resultant increase in spontaneous mutation rate. To