Methylation of deoxycytidine incorporated by excision-repair synthesis of DNA

Journal Article · Wed Sep 01 04:00:00 EDT 1982 · Cell; (United States)

DOI:https://doi.org/10.1016/0092-8674(82)90248-3· OSTI ID:6524144

Kastan, M B; Gowans, B J; Lieberman, M W

Methylation of deoxycytidine incorporated by DNA excision-repair was studied in human diploid fibroblasts following damage with ultraviolet radiation, N-methyl-N-nitrosourea, or N-acetoxy-2-acetylaminofluorene. In confluent, nondividing cells, methylation in repair patches induced by all three agents is slow and incomplete. Whereas after DNA replication in logarithmic-phase cultures a steady state level of 3.4% 5-methylcytosine is reached in less than 2 hr after cells are labeled with 6- 3H-deoxycytidine, following ultraviolet-stimulated repair synthesis in confluent cells it takes about 3 days to reach a level of approximately 2.0% 5-methylcytosine in the repair patch. In cells from cultures in logarithmic-phase growth, 5-methylcytosine formation in ultraviolet-induced repair patches occurs faster and to a greater extent, reaching a level of approximately 2.7% in 10-20 hr. Preexisting hypomethylated repair patches in confluent cells are methylated further when the cells are stimulated to divide; however, the repair patch may still not be fully methylated before cell division occurs. Thus DNA damage and repair may lead to heritable loss of methylation at some sites.

• Research Organization: Department of Pathology, Washington University School of Medicine, St. Louis, Missouri
• OSTI ID: 6524144
• Journal Information: Cell; (United States), Journal Name: Cell; (United States) Vol. 30:2; ISSN CELLB
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550300 -- Cytology
560121* -- Radiation Effects on Cells-- External Source-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
AZINES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL PATHWAYS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BIOSYNTHESIS
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
DEOXYCYTIDINE
DNA
ELECTROMAGNETIC RADIATION
FIBROBLASTS
HETEROCYCLIC COMPOUNDS
KINETICS
METHYLATION
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RADIATIONS
REACTION KINETICS
RECOVERY
REPAIR
RIBOSIDES
SOMATIC CELLS
SYNTHESIS
ULTRAVIOLET RADIATION