Site-specific mutagenesis by O sup 6 -alkylguanines located in the chromosomes of mammalian cells: Influence of the mammalian O sup 6 -alkylguanine-DNA alkyltransferase

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.22.8620· OSTI ID:6956584

Ellison, K S; Dogliotti, E; Connors, T D; Basu, A K; Essigmann, J M ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

A plasmid was constructed in which a single guanine residue was replaced with either O{sup 6}-methylguanine or O{sup 6}-ethylguanine, two of the DNA adducts formed by carcinogenic alkylating agents. The vectors were introduced in parallel into a pair of Chinese hamster ovary cells, in which one member of the pair was deficient in the repair enzyme O{sup 6}-alkylguanine-DNA alkyltransferase (mex{sup {minus}}) and the other was proficient in this activity (mex{sup +}). The vector integrated into and replicated within the respective host genomes. After intrachromosomal replication, the DNA sequence in the vicinity of the originally adducted site of each integrated vector was amplified from the host genome by using the polymerase chain reaction and was analyzed for mutations. High levels of mutation were observed from the O{sup 6}-methylguanine- and O{sup 6}-ethylguanine-containing vectors replicated in mex{sup {minus}} cells. DNA sequencing revealed the induced mutations to be almost exclusively G {yields} A transitions. By contrast, little or no mutagenesis was detected when the adducted vectors were introduced into mex{sup +} cells, indicating the significant role of the O{sup 6}-alkylguanine-DNA alkyltransferase in the repair of O{sup 6}-methylguanine and O{sup 6}-ethylguanine in these mammalian cells.

• OSTI ID: 6956584
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 86:22; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADDUCTS
ALKYLATING AGENTS
AMINES
ANIMAL CELLS
AROMATICS
AZAARENES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CARCINOGENESIS
CELL CONSTITUENTS
CHEMISTRY
CHO CELLS
DAYS LIVING RADIOISOTOPES
DNA ADDUCTS
DNA REPAIR
DNA SEQUENCING
ELECTROPHORESIS
ENZYMES
GENE RECOMBINATION
GENETIC EFFECTS
GUANINE
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MUTAGENESIS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PATHOGENESIS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PLASMIDS
PURINES
RADIOISOTOPES
RECOVERY
REPAIR
STRUCTURAL CHEMICAL ANALYSIS
TRANSFERASES