DNA repair within nucleosome cores of UV-irradiated human cells

Journal Article · Tue May 22 00:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00472a005· OSTI ID:6645014

Jensen, K A; Smerdon, M J ^[1]

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1. Washington State Univ., Pullman (USA)

We have compared the distributions of repair synthesis and pyrimidine dimers (PD) in nucleosome core DNA during the early (fast) repair phase and the late (slow) repair phase of UV-irradiated human fibroblasts. As shown previously, repair synthesis is nonuniform in nucleosome core particles during the fast repair phase, and the distribution curve can be approximated by a model where repair synthesis occurs preferentially in the 5' and 3' end regions. In this report, we show that, during the slow repair phase, (3H)dThd-labeled repair patches are much more uniformly distributed in core DNA, although they appear to be preferentially located in sequences degraded slowly by exonuclease III. This change in distribution cannot be explained by an increase in patch size during slow repair, since the size of these patches actually decreases to about half the size measured during the fast repair phase. Furthermore, PD mapping within core DNA at the single-nucleotide level demonstrated that, at least within the 30-130-base region from the 5' end, there is little (or no) selective removal of PD during the fast repair phase. However, the nonuniform distribution of repair synthesis obtained during fast repair throughout most of the core DNA region (approximately 40-146 bases) is accounted for by the nonuniform distribution of PD in core DNA. The near-uniform distribution of repair synthesis observed during slow repair may result from more extensive nucleosome rearrangement and/or nucleosome modification during this phase.

• OSTI ID: 6645014
• Journal Information: Biochemistry; (USA), Vol. 29:20; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
FIBROBLASTS
DNA REPAIR
GENETIC RADIATION EFFECTS
MAN
NUCLEASES
NUCLEOSOMES
PYRIMIDINE DIMERS
THYMIDINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ULTRAVIOLET RADIATION
ANIMAL CELLS
ANIMALS
AZINES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CHROMATIN
CONNECTIVE TISSUE CELLS
ELECTROMAGNETIC RADIATION
ENZYMES
ESTERASES
GENETIC EFFECTS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROLASES
ISOTOPE APPLICATIONS
MAMMALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHODIESTERASES
PRIMATES
PYRIMIDINES
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
RIBOSIDES
SOMATIC CELLS
VERTEBRATES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture
550201 - Biochemistry- Tracer Techniques